CA2104824A1 - Method and apparatus for processing data for a visual-output device with reduced buffer memory requirements - Google Patents
Method and apparatus for processing data for a visual-output device with reduced buffer memory requirementsInfo
- Publication number
- CA2104824A1 CA2104824A1 CA002104824A CA2104824A CA2104824A1 CA 2104824 A1 CA2104824 A1 CA 2104824A1 CA 002104824 A CA002104824 A CA 002104824A CA 2104824 A CA2104824 A CA 2104824A CA 2104824 A1 CA2104824 A1 CA 2104824A1
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- Prior art keywords
- data
- representation
- region
- compressing
- page
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
- 230000015654 memory Effects 0.000 title claims abstract description 58
- 238000000034 method Methods 0.000 title claims description 120
- 238000012545 processing Methods 0.000 title claims description 18
- 238000007906 compression Methods 0.000 claims abstract description 165
- 230000006835 compression Effects 0.000 claims abstract description 164
- 230000000007 visual effect Effects 0.000 claims description 17
- 238000004590 computer program Methods 0.000 claims 2
- 238000010586 diagram Methods 0.000 description 17
- 230000008569 process Effects 0.000 description 16
- 238000012360 testing method Methods 0.000 description 8
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- 238000004891 communication Methods 0.000 description 4
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Classifications
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N1/00—Scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission; Details thereof
- H04N1/41—Bandwidth or redundancy reduction
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06K—GRAPHICAL DATA READING; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
- G06K15/00—Arrangements for producing a permanent visual presentation of the output data, e.g. computer output printers
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06K—GRAPHICAL DATA READING; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
- G06K15/00—Arrangements for producing a permanent visual presentation of the output data, e.g. computer output printers
- G06K15/02—Arrangements for producing a permanent visual presentation of the output data, e.g. computer output printers using printers
- G06K15/18—Conditioning data for presenting it to the physical printing elements
- G06K15/1801—Input data handling means
- G06K15/181—Receiving print data characterized by its formatting, e.g. particular page description languages
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06K—GRAPHICAL DATA READING; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
- G06K15/00—Arrangements for producing a permanent visual presentation of the output data, e.g. computer output printers
- G06K15/02—Arrangements for producing a permanent visual presentation of the output data, e.g. computer output printers using printers
- G06K15/18—Conditioning data for presenting it to the physical printing elements
- G06K15/1848—Generation of the printable image
- G06K15/1849—Generation of the printable image using an intermediate representation, e.g. a list of graphical primitives
- G06K15/1851—Generation of the printable image using an intermediate representation, e.g. a list of graphical primitives parted in a plurality of segments per page
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06K—GRAPHICAL DATA READING; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
- G06K15/00—Arrangements for producing a permanent visual presentation of the output data, e.g. computer output printers
- G06K15/02—Arrangements for producing a permanent visual presentation of the output data, e.g. computer output printers using printers
- G06K15/18—Conditioning data for presenting it to the physical printing elements
- G06K15/1848—Generation of the printable image
- G06K15/1856—Generation of the printable image characterized by its workflow
- G06K15/1861—Generation of the printable image characterized by its workflow taking account of a limited available memory space or rasterization time
- G06K15/1865—Generation of the printable image characterized by its workflow taking account of a limited available memory space or rasterization time by compressing the rasterized print data
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
- G06T11/00—2D [Two Dimensional] image generation
- G06T11/60—Editing figures and text; Combining figures or text
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
- G06T9/00—Image coding
- G06T9/005—Statistical coding, e.g. Huffman, run length coding
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
- G06T9/00—Image coding
- G06T9/007—Transform coding, e.g. discrete cosine transform
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03M—CODING; DECODING; CODE CONVERSION IN GENERAL
- H03M7/00—Conversion of a code where information is represented by a given sequence or number of digits to a code where the same, similar or subset of information is represented by a different sequence or number of digits
- H03M7/30—Compression; Expansion; Suppression of unnecessary data, e.g. redundancy reduction
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06K—GRAPHICAL DATA READING; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
- G06K2215/00—Arrangements for producing a permanent visual presentation of the output data
- G06K2215/0002—Handling the output data
- G06K2215/0062—Handling the output data combining generic and host data, e.g. filling a raster
- G06K2215/0065—Page or partial page composition
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06K—GRAPHICAL DATA READING; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
- G06K2215/00—Arrangements for producing a permanent visual presentation of the output data
- G06K2215/0002—Handling the output data
- G06K2215/0062—Handling the output data combining generic and host data, e.g. filling a raster
- G06K2215/0071—Post-treatment of the composed image, e.g. compression, rotation
Abstract
ABSTRACT OF THE DISCLOSURE
A two-dimensional page representation to be printed has a combination of text, graphic and image representation types. A data memory stores data representative of the page representation. A program memory stores program instructions including a plurality of different algorithms for compressing data associated with corresponding different representation types and their combinations. A processor is coupled to the data and program memories for (a) identifying separate data for each of a plurality of regions containing collectively the page representation, with the data for each region corresponding to the portion of the page representation contained in that region; (b) determining the types of representations and boundaries of each type of representation and the combinations of types contained in each region;
(c) rasterizing and compressing the data associated with the determined types of representations for each region with algorithms based on selected compression factors; (d) storing sequentially the compressed data for each region; and (e) when needed for printing, sequentially for each region, reading the corresponding stored data, decompressing the read data, and transmitting the decompressed data to the print device for printing.
A two-dimensional page representation to be printed has a combination of text, graphic and image representation types. A data memory stores data representative of the page representation. A program memory stores program instructions including a plurality of different algorithms for compressing data associated with corresponding different representation types and their combinations. A processor is coupled to the data and program memories for (a) identifying separate data for each of a plurality of regions containing collectively the page representation, with the data for each region corresponding to the portion of the page representation contained in that region; (b) determining the types of representations and boundaries of each type of representation and the combinations of types contained in each region;
(c) rasterizing and compressing the data associated with the determined types of representations for each region with algorithms based on selected compression factors; (d) storing sequentially the compressed data for each region; and (e) when needed for printing, sequentially for each region, reading the corresponding stored data, decompressing the read data, and transmitting the decompressed data to the print device for printing.
Description
8 2 ~
METHOD AND APPARA~US FOR PROCESSING DATA FOR A
VlSUAL4lJTPUT DEVICE WITH REDUCED BUFFER ME~AORY FlEC~UlREMENTS
BACKGROUN0 OF THE iNVENTI(~N
Field of the Invention This invention relates to a method and appara us for processing data representative of a visual representation, typically induding a combination of 10 text, graphics, and images, that is to be output to a visual-output device, such as a screen display or print device. More particularly it relates to such a method and apparatus in which a data memory, ref~rred to herein functionally as a "buffer memory", has reduced capacity requirements resul~ing from the selective compression of data.
Related Art The preferred embodiment of, and preferred r~ethod of practicing the present invention is directed to printers that form a raster image typically connected indirectly over a network, or directly to a computer for printing 20 documents created on the computer. The invention is realizable for other forms of output devices as well, such as a video display generated on a CRT monitor or an LCD. Thus, the device creating the actual visual representation is referred to as a "visual-output device~. The visual area within which the visual representation exists is referred to as a ~page~, rega~dless of its actual form.25 The complete visuai representation is referred to as a ~page representation''. A
separately defined part of a page representation is referred to as an ~object".
One of the significant cost elements in a conYentional printer is a buffer memory, also referred to as a frame buffer, for storing raster data defining thepage representation. Conventional printer configurations employ buffer 30 memories that are capable of storing all of the rastef data required to define each pixel on a page. An extensive amount of memory capacity is therefore SPECIFICATION
~~
METHOD AND APPARA~US FOR PROCESSING DATA FOR A
VlSUAL4lJTPUT DEVICE WITH REDUCED BUFFER ME~AORY FlEC~UlREMENTS
BACKGROUN0 OF THE iNVENTI(~N
Field of the Invention This invention relates to a method and appara us for processing data representative of a visual representation, typically induding a combination of 10 text, graphics, and images, that is to be output to a visual-output device, such as a screen display or print device. More particularly it relates to such a method and apparatus in which a data memory, ref~rred to herein functionally as a "buffer memory", has reduced capacity requirements resul~ing from the selective compression of data.
Related Art The preferred embodiment of, and preferred r~ethod of practicing the present invention is directed to printers that form a raster image typically connected indirectly over a network, or directly to a computer for printing 20 documents created on the computer. The invention is realizable for other forms of output devices as well, such as a video display generated on a CRT monitor or an LCD. Thus, the device creating the actual visual representation is referred to as a "visual-output device~. The visual area within which the visual representation exists is referred to as a ~page~, rega~dless of its actual form.25 The complete visuai representation is referred to as a ~page representation''. A
separately defined part of a page representation is referred to as an ~object".
One of the significant cost elements in a conYentional printer is a buffer memory, also referred to as a frame buffer, for storing raster data defining thepage representation. Conventional printer configurations employ buffer 30 memories that are capable of storing all of the rastef data required to define each pixel on a page. An extensive amount of memory capacity is therefore SPECIFICATION
~~
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typically required. A black-and-white representation fcr a 8.5 inch x 11 inch sheet of paper at a pixel density of 300 dpi (dots or p~els per inch) requires in excess of 1 MByte (1 million 8-bit bytes) of memory. Higher spatial and tonal resolutions, color printing and larger paper sizes requ,re even more memory. A
5 continuous tone, four-color representation at a pixel c'~nsity of 600 dpi for the same sized page requires about 135 MBytes of memo y. Since the printer costs rise with memory size, it is desirable to provide printers with reduced memory requirements.
A memory device known by the proprietary name of ~Memory MiserU
10 produced by Advanced Micro Devices of Santa Clara, California, stores data ina resident memory by applying a compression algori~m to all of the data input.
When required for output it is decompressed based on the reverse of the compression algorithm and output. If used in a printer, such a device would reduce the amount of memory required. However, the memory would need to 15 be at least large enough to store the most complex page representation in order to be able to process any page that is input. This printer would have little flexibility in processing the variety of pags representa~ons possible with present day printers.
SUMMARY OF TllE INVENTION
Th~ present invention provides a method for using, and an apparatus permitting a reduced-size memory. Further, it provides a method and apparatus that can accommodate a variety of page representation characteristics and data processing objectives.
The invention is directed generally to an apparatus and a method for processing data representative of a page representation for output to a visual-output device, such as the electro-mechanical printing apparatus (also referred to as the print device), of a printer. The method begins with the step of receiving data that deflnes a page representation. A plurality of regions of thepage are selected, which regions contain at least a portion of the page . . . . ~
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Q1~8~4 representation. In one aspect of the invention, separate data for each such region is identified corresponding to the portion of the page representation contained in that region. Data identified for at least one of the regions is then compressed, using at least one compression algorithm and stored. For producing the page representation after storing the compressed data, the compressed data is decompressed and transmitted to the visual-output device.
In another aspect of the invention, at least one compression factor and a plurality of compression algorithms are provided. The compression factor has a determinable value that is related to a reference value. A compression algorithm is then chosen based on the relationship of the determined value of the compression factor to the reference value.
More specifically, the preferred embodiment of the invention is an apparatus for printing a two-dimensional page representation composed potentially of text, graphic and image objects (object representations) individually, and in combination. A print device is responsive ~o raster data for printing a page containing the page representation. An input device, such as a personal computer or workstation, is used for inputting data defining the page representation. A program memory stores program instructions including a piurality of different algorithms for compressing the data associated with corresponding different representation types and their combinations. The selection of compression algorithms is based in part on balancing the compression factors of compression ratio, computational complexity, and visual quality. A processor is coupled to the input device, print device, program memory and a data memory for executing the stored program instructions.
The processor is responsive to the data input in the form of descriptive commands for identifying data for each of a plurality of ordered regions or bands containing collectively at least a portion, and preferably, all of the page representation. The data for each region corresponds to the portion of the page representation contained in that region. Some regions may not contain data. The descriptive commands, which are not necessarily band limited, are SPEClFiCATlON 3 .
,. . . . . .
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converted into lists of primitive elements selected from a set of primitive elements. Each primitive element represents at least a portion of an object representation. These lists are referred to as display lists. There is preferably a display list for each region, although the display list could be for the entire 5 page, or for other defined regions.
The types (and combinations of types) of representations and boundaries (referred to as bounding boxes) of each type contained in each region are determined. The display list data associated with the determined types of representations for each region is rasterized into an uncompressed 10 band and then compressed using algorithms corresponding to the analysis of certain compression factors. Rasterizing refers generally to the conversion of high-level descriptive commands into rasters. Data associated with primitive elements is often already in raster form. However, for purposes of this discussion, rasterizing refers to the conversion of display list data for a region 15 into raster form without regard for whether or not the data associated with the corresponding primitive elements is already in raster form.
The compression factors may, and preferably do include compression goals specifying target visual quality, compression ratio, and computational complexity. Compression ratio re~ers generally to the bytes of memory required 20 to hold the compressed data relative to the bytes of memory required to hold the same data uncompressed. Additionally considered are such factors as the type of representation, content of individual boundin~ boxes, overall content ofthe page representation, estimated versus actual compression being achieved, and the number of passes or attempts made at compressing the data. Other 25 factors may also be used, and some of these factors may not be used in all situations. For example, the factors could be prioritized so that some are givenmore weight than others. As an extension of this, in certain situations some factors could be given no weight at all relative to other factors.
Some of these factors inherently have values that are readily determined.
30 Others relate to characteristics or features the state cf which is determined and ~ Q~82~
a value assigned accordingly. For instance, the three representation types of text, graphics and images could be assigned arbitrary respective identifier values 1, 2, and 3.
An algorithm, generally speaking, refers to a particular algorithm or 5 combination of algorithms with particular parameter values. Thus, a change in parameter values results in a change in the algorithm.
The compressed data is stored sequentially by region. In the preferred embodiment, when required for printing, data for a region is read and decompressed. Depending on the system configuration, the compressed data 10 may be transmitted to an external printer or stored pending requirement of the data by the print device. The data is then transmitted to the print device for printing. Producing data (display lists) for each region and defining the regions to conform to the sequential output of raster data to an output device minimizesthe number of times the data is decompressed, data added, and then 15 retcompressed. During this overall process ~data~ defining the page representation takes the form of descriptive commands, display lists and associated information, and raster data.
Data representative of the page representation is thus compressed and held in memory until such time as it is required by the print device for printing, 20 or until the content of a region is changed. The data for the regions are swapped in and out of the compressed-data memory using the selected compression and corresponding decompression algorithms, Uhereby reducing substantially the buffer memory requirements. This and other features and advantages of the present invention will be apparent from the following detailed ~ ~:
25 description of the preferred embodiment of the invention and as illustrated in the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of an apparatus made according to and for 30 practicing the method of the invention.
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FIG. 2 is an illustration of a page having different types ol two-dimensional representations FIG. 3 is a flow diagram summarizing a method of practicing the invention.
FIG. 4 is a flow diagram of step 58 of the diagram of FIG. 3.
FIG. 5 illustrates visually the development of non-intersecting bounding boxes from bounding boxes of different representation types that overlap according to the method of the diagram of FIG. 4.
FIG. 6 is a simplified graphic example of overlapping bounding boxes with identifying coordinates used in the method of the diagram of FIG. 4.
FIG. 7 is a flow diagram illustrating the development of non-intersecting bounding boxes corresponding to step 122 in FIG. 4.
FIG. 8 is a flow diagram of step 78 of the diagram of FIG. 3.
FIG. 9 is a flow diagram of step 80 of the diagram of FIG. 3.
FIG. 1û is a functional block diagram corresponding to the apparatus of FIG. 1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT AND METHOD
Referring initially to FIG. 1, a generalized visual-representation-generating 20 system made according to the present invention is shown generally at 10. It includes a visual information source 12 connected via a communication link 14 to an output-data generator 16. Generator 16 is connected to a visual-output device 18 via a communication link 20. As will be seen, various embodiments are realizable from this general structure. Output data generator 16 can be 25 resident within a host unit including source 12, can be resident within an output unit including visual-output device 18, or can be functionally split between a host unit and an output unit.
In the typical instance when data generalor 16 and output device 18 comprise a laser or other raster printer, information source 12 is a conventional 30 work station or other computer-based system, such as an Apple Macintosh or :
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IBM PC. The term print device is also used herein as an exar~ple of a visual-output device. In the preferred embodiment, this term applies to the electro-mechanical apparatus responsive to raster data for producing a printed page.
Generator 16 could also be incorporated in a computer or wofkstation, such as a computer-based system as has just been mentioned, programmed to function as described herein, for controlling a raster display or printing device, as hasalso been mentioned. Further, as is discussed with referenoe to FIG. 10, a host unit could generate and output the compressed data and an output unit could receive the compressed data, decompress it and transmit it to a resident visual-output device.
The preferred embodiment of the invention is thus directed to the printing of two-dimensional pixel representations. The general concepts are e~ually applicable to three (or more) dimensional representations to the extent they arerealizable in the system of FIG. 1.
Generator 16 includes an input\output controller 22 coupled to communication links 14 and 20. A conventional CPU (central processing unit) or processor 24 is coupled to controller 22, as well as to a read/write or random access memory (RAM) 26, ussd partially as a buffer memory, for storing data, and a read only memory ~ROM) 28 for storing pro~ram -instructions and fixed information, such as nonvariable data and compression and decompression algorithms, as is discussed in further det~1 with reference to FlGs. 3, 5, and 7-10. Any of a variety of conventional CPU's may be used, depending on the actual application. Further, other forms of hardware that -accomplish the same functions can be used.
FIG. 2 illustrates a page 30 having a page representation 34 that could be defined by data input by the input device using a conventional page-description language, such as the language available from A~obe Systems Incorporated known by the name PostScript. In the printer environment, as a PostScript file is created on source 12 (FIG. 1), objects can be created in any arbitrary order or fashion on a page. The objects are defined by one or mors .. , . ,. ~. .
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descriptive commands. As used herein, then, an ~'ob;~ct-defir,ing command" is the command or collection of commands that define en object.
Different compression schemes have been found to be pr'eferable for the different representation types of text, graphics, and images. For instanoe, the S human eye is often less sensitive to changes in images than to degradations insomething as well defined as text. Thus, technically lossy compressiorl schemes such as JPEG, when used at reduced levels of compression for images, can be visually lossless. Further, by the nature of graphics objects, some otherwise lossy schemes may be usable without compromising spatial 10 resolution. The LZW technique has been found to work well on text, runlength coding is effective for graphics and text/graphics combinations, and the JPEG
technique is useful for images. It is therefore advantageous to identify the different types of objects in a page representation.
Continuing to refer to FIG. 2, page 30 has defined boundaries 1~ represented by border line 32. The boundaries thus represent the maximum area wiShin which page representation 34 is to be produced. Page representation 34 includes the following objects on a background of a single color. A title or main heading 36 is formed of text in different c~lors (represented by the different tones). A subheading 38 identifies a text representation 40; a subheading 42 identifies a graphics representation 44; and a subheading 46 identifies an image representation 48. These subheadings are text representations in relatively large fonts and, along with text representation 40, are all a single color different than the background color. Text representation 40 is in a reduced font. Graphics representatlon 44 has grid identifiers 50 in the form of alphanumeric characters (text), and a bar chart section 52 composed of bars of different colors. Image representation 48 is simply an array of pixels of varying colors.
Page representation 34 incorporates separate examples of large and small text, graphics, and image representations or o~jects. In a more complex page representation various of the different objects could overlap. That is, they .
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could be printed at least partially on a cornmon area. The preferred methocl of the present invention is designed to take such overlapping areas into consideration, as is discussed in greater detail below.
A generalized flow diagram chart of a process or method 54 according to 5 the invention is provided in FIG. 3. Processor 24 of FIG. 1 executes instructions to function as an interpreter that recognizes the PostScript descriptive commands input as page data from source 12, as is provided by step 56 in ~he flow diagram of FIG. 3. In the general method of the invention, the page description data is divided into at least one, and preferably R dMerent data 10 regions at step 58. The regions can be determined in advance, as is the case with the preferred embodiment and therefore be determined arbitrarily with reference to a particular page representation. They could also be determined dynamically for each page representation. Referring to FIG. 2, an example of a dynamic determination would be to divide the page into separate regions corresponding to title heading 36, text subheading 3~, text section 40, graphicssubheading 42, each of grid identifiers 50, bar chart section 52, image subheading 46 and image section 48. In the preferred embodiment of the invention, however, in which raster data is produced for printir~ a page, the page area is divided into a plurality of fixed regions in the form of parailel 20 bands. The bands are chosen and ordered to correspond to the generation of raster data for output to a print device, and is therefore related to the resolution and scan order of the output device.
Referring again to FIG. 2, page 30 is shown for purposes of illustration divided into sixteen bands 60-75. When it is time to print, data for band 60 is 25 read out and decompressed first and the data progresses sequentially through the bands until data for the last band 75 is output. These bands each correspond to multiple raster scans~ of the page and provide for ordering the data in a way that will make the data readily available for printing. An actual letter-size page having a resolution of 300 dpi may be divided into about 20 to 30 40 bands.
SPECIFICATION g 2 ~ 4 As has been mentioned, the present invention provides for a reduction in the amount of memory required through the use of compression techniques, as is represented by step 78 in FIG. 3. By compressing a rasterized version of the descriptive data of the page representation, according to the preferred 5 embodiment, and decompressing it as needed by the printer or dispiay, the amount of RAM needed may be drastically reduced.
This memory reduction is achieved by storing in the working RAM a compressed representation of what is conventionally stored uncompressed in a frame buffer. Raster data is created for one region at a time and stored 10 uncompressed in RAM 26. This data is then compressed and re-stored in F~M
26 until needed. The data for all the regions is ultimately processed in this way until da~a for essentially all the regions is compressed and stored. In the preferred embodiment of the present invention, as data for each region is requested for output (printing), it is decompressed and output to the output 15 device (print device), as represented by step 80 in FIG. 3.
By compressing the data for the regions in the reverse order required for output to the output device, the compression/decompression cycle of the last region may be avoided, since it can simply be rasterized and output directly.
Also, depending on the circumstances, the decompression algor-~hm typically 20 is, but may not be exactly the reverse of the compression algorithm. When the outpu~ (page printing) is completed, process 54 ends for that page.
The following description of this process is directed to processing data for a single page. It will be understood that multiple pages may also be processed at a time using a similar system, so that dmerent ones of the steps 25 take place simultaneously for various regions of the same or different pages.Step 58 is shown in further detail by the flow diagram of FIG. 4. High level descriptive (such as PostScript) commands are input into data generato 16 from a source 12 as shown in FIG. 1. As has been described, these commands define, usually in no particular order, where text, graphics, and 30 image objects appear. Some of the commands do not define a particular 8 2 ~
object. These commands may be directed to identifying locations on a page, what color to use, and the like. Text typically includes definitions of font andcharacter size, as well as character identifiers and other informalion, such as the color of the text. Graphics are defined by area fills and strokes of arb~rary 5 color, and images are usually provided by bit or byte patterns.
Referring again to FIG. 4, the first object-defining command is selected at step 82. The intersection of the obiect defined by the command with each of the R regions (bands) is then determined, as shown generally at 84. Iterative loop step 86 symbolizes the sequential determinations made for each region.
10 When the first region is selected, a determination is made at 88 as to whether the object described by the command intersects the region. If there is no intersection, the next region is selected at s~ep 86 and the determination repeated for that region.
If there is an intersection, primitive elements, collectively referred to as a 15 display list, are generated for the portion of the object in the region at step 90.
Primitive elements are basic object portions or ~building blocksR that, when combined, form a new definition of an object. Character masks are used to define text. Geometric shapes, such as trapezoids and run arrays (bit patterns) are both graphics primitive elements. Because of the random color and - 2~ intensity changes, images are defined by the actual image descriptions. In some instances, these primitive elements are stored in the display list indirectly via pointers. Preferably, a single display list is generated for each region. Ashas been mentioned, it would also be possible to have a single display list for a page with allocation of data to a region taking place as raster data for the 25 region is stored prior to compressing.
Each high level input object-defining command implicitly has a corresponding representation type, such as text, graphics or image. Other ways of classifying the object-defining commands may also be used. In this embodiment, the primitive element has an associated representation type 30 corresponding to this implicit type. A bounding box is also determined for each 2~4~2~
region in which a portion of an object exists. A representation type is assignedto each bounding box based on the associated primitive element type. In the preferred embodiment, the representation type is one of the three preferred types of text, graphics and image.
A bounding box is a defined area containing an object or object portion in the region. In an X-Y coordinate system, a bounding box is preferably a rectangle defined by the coordinates of the lower left and upper right corners.
Other definitions for bounding boxes, such as trapezoids, could also be used.
l~ere is thus potentially a single bounding box for each representation type in each region, referred to as a regional bounding box. As is discussed below, as an object is added to a region, the regional bounding box of the same type is preferably expanded to include the area of the new primitive element(s) and the display list for the region is updated, as represented by step 92.
Collecting only one text, one graphic and one image bounding box for each region sa~isfies a requirement of computational simplicity while processingthe primitive elements. However, it does so at the expense of lost local information. For example, if an ~a~ is marked on the left side of the region anda "b- is marked on the right side of the region, there would be a tex~ bounding ~; box that spans the width of the region although characters do not fill this entire span. Consequently, a logical extension of this invention would be to perform this information collection on a smaller region basis, such as having two or three regions across the width of a page. This wo~uld provide more local tracking of the objects in the regions. In general, as has been discussed, the page can be divided into any arbitrary regions.
FIG. 5 shows visually the development of bounding boxes. Bounding boxes are also referred to herein, in a general sense, as regions. Each bounding box identifies a specific region of a page in which an object, collection of objects, or portions thereof, exists. As was described with reference to page30 shown in FIG. 2, the selected regions can be set dynamically to correspond to the objects in each page representation. A bounding box is thus a specific ~` 2 1 ~
.
:
example of this concept. However, in the following d:~cussion, the term region refers to the bands as shown in FIG. 2 and not to bo!~nding boxes.
The leH-most representation in FIG. s illustrates a regional graphics bounding box 100 and a regional text bounding box 102. The text bounding 5 box was formed by combining all the bounding boxes (not shown) for characters 1û4 (t), 105 (e) and 106 (x). Bounding box 102 is enlarged by adding bounding box 107 associated with the addition of a new character 1û8 "t" to ~tex~, resulting in enlarged bounding box 110 shown in the center of FIG. 5 containing the word "text".
Referring again ~o FIG. 4, this process of building regional bounding boxes of each type continues until the descriptive command is processed for each region, or until intersection with all regions has been determined as described. After the last region is checked, a deterrr,ination is made at step 112 if there is another command. If there is, the next command is selected at step 114 and process 84 is repeated. If there are no other commands, then intersecting bounding boxes for each region are determined, as shown generally at 116.
In the discussion to follow, H will be seen that different compression algorithms are applied to the different types and combinations of types of 20 representations. The following procedure divides the bounding boxes into non-intersecting bounding boxes that are exclusively of a particular type or a particular combination of types. This allows different objects of different types to have the associated raster representation compressed wit'n different algorithms. During this procedure, the size of boun~lng boxes that contain a 25 combination of overlapping objects of different types are minimized.
As controlled by iterative loop 118, the regions are sequentially checked to see if the bounding boxes of the different types intersect, as shown in step 12û. If not, the next region is checked. If the bounding boxes do intersect, thebounding boxes for the region are divided at step 122 into non-intersecting 30 bounding boxes. This process is illustrated visually in the right illustration of . . .,: . . .
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FIG. 5 with shaded boxes representing different non-intersecting bounding boxes. These non-intersectiny bounding boxes may also be re~erred to as subregions. Regional bounding box 110 is divided into non-intersecting bounding boxes 124, 125 and 126. Similarly, regional graphics bounding box 100 is divided into non-intersecting bounding boxes 125, 128, and 129. Non-intersecting text bounding boxes 124 and 126 have only text representations in them. Non-intersecting graphics bounding boxes 128 and 129 have only graphics representations in them. Remaining bounding box 125 has a combination of both text and graphics representations, as noted in the figure.
FIG. 6 is a simplified representation of a combination of three different original bounding boxes 130, 132 and 134 in a region 136 of types text ~r), - graphics (G), and image (I), respectively, as shown. This figure does not represent the same bounding box configuration as FIG. 5, but is used to illustrate the method of dividing intersecting bounding boxes of all three representation types. In order to simplify the explanation, adjacent coordinate values are used and only represent relative pixel coordinates. Actual values aretypically much higher and are typically not adjacent. Bounding box 130 is defined by the lower left and upper right coordinates having the (~(, Y) values (0,2)(6,3). Similarly, bounding boxes 132 and 134 have the coordinate values (1,1)(2,4) and (3,0)(5,5), respectively. In order to delineate between adjacent bounding boxes, the pixels along the ieft and bottom boundaries are included in the bounding box and the pixels along the right and top boundaries are excluded. Thus, the upper right coordinate identifying each bounding box is not included in the bounding box.
The process of dividing these regional bounding boxes into non-intersecting bounding boxes may be thought of as a distilling operation. The method is illustrated in the flow diagram of FIG. 7 with reference to the chart of FIG. 6. Starting with step 140, the bounding box coordinates are listed and the Y coordinates are ordered from lowest to highest. This procedure may also be : 30 performed in reverse using the highest coordinates first instead of the lowest.
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In the following discussion, the reference to X and Y coordinates may be reversed and the results will be the same. In this case the Y coordinates are:
o, 1, 2, 3, 4 and 5. The two lowest Y coordinates (0 and 1) are selected initialiy, and the X coordinates that are associated with the selected Y coordinates are ordered during step 142. Thus, Y = 0,1 and X=3,5 as provided by bounding box 134 X coordinates 1 and 2 for Y = 1, which define the bonom boundary of bounding box 132, are not used since this forms the top of what would otherwise be a test box (1,0)(2,1). This top line is not included in the test box, so there is no intersection with bounding box 132.
The next two lowest X coordinates are selected initially, during step 144.
In this case there are only two X coordinates. A test is then made during step 146 to determine if lhe resulting test box is in one of the original bounding boxes. Test box (3,0)(5,1), the top of which is shown by a dotted line in FIG. 6, is in bounding box 134 and is identified as bounding box A,. The subscript I
refers to the bounding box type, which in this case is image. rnis representation type and the coordinates of bounding box A are stored during step 148.
If the test box is not in an original bounding box, it is ignored and step 148 bypassed. The next step 150 is a determination as to whether thsre are more X coordinates for the existing pair of Y coordinates, 0,1. If so the next two X coordinates would be 5 and whatever the next one is. Since there are no more X coordinates, a test is made at step 152 to determine ~ there are any more Y coordinates. If not, the distilling procedure is completed. However, in this example, we are just beginning. There being another Y, the procedure retùrns to step 142 and repeats the above steps for Y=1,2.
Rather than go through the process step-by-step verbally, the following table is used to show the various steps involved in identifying all the non-intersecting bounding boxes A through M.
Y ¦ X ¦TEST EIOX ¦ ID ¦ STORE? ¦ TYPE
0,1,2,3,4,5 . . . .
0,1 ; ' . _ 3,5 . I
3,5 13,0)(5.1) A YES _ 1,2 1,2,3,5 _ ' .
_ I
1,2 (1,1)(2,2) 8 YES
2,3 (2,1)(3,2) C NO
3,5 (3.1 ) (5,2) D YES
2,3 0,1,2,3,5,6 _, =
l 0,1 (0,2)(1,3) E YES T
l 1,2 (1,2)(2,3) F YES T,G
2,3 l2,2)t3,3) G YES T
3,S 13.2)(5.3) H YES T,l 5,6 (5,2)(6,3) l YES T
. 1 3,4 _ _ =
l 1,2,3,5 . . .
1,2 (1,3) (2~4) J YES G
2,3 (2,3) (3,4) K NO
.` 3,5 (3,3)(5.4) E YES _ ¦
typically required. A black-and-white representation fcr a 8.5 inch x 11 inch sheet of paper at a pixel density of 300 dpi (dots or p~els per inch) requires in excess of 1 MByte (1 million 8-bit bytes) of memory. Higher spatial and tonal resolutions, color printing and larger paper sizes requ,re even more memory. A
5 continuous tone, four-color representation at a pixel c'~nsity of 600 dpi for the same sized page requires about 135 MBytes of memo y. Since the printer costs rise with memory size, it is desirable to provide printers with reduced memory requirements.
A memory device known by the proprietary name of ~Memory MiserU
10 produced by Advanced Micro Devices of Santa Clara, California, stores data ina resident memory by applying a compression algori~m to all of the data input.
When required for output it is decompressed based on the reverse of the compression algorithm and output. If used in a printer, such a device would reduce the amount of memory required. However, the memory would need to 15 be at least large enough to store the most complex page representation in order to be able to process any page that is input. This printer would have little flexibility in processing the variety of pags representa~ons possible with present day printers.
SUMMARY OF TllE INVENTION
Th~ present invention provides a method for using, and an apparatus permitting a reduced-size memory. Further, it provides a method and apparatus that can accommodate a variety of page representation characteristics and data processing objectives.
The invention is directed generally to an apparatus and a method for processing data representative of a page representation for output to a visual-output device, such as the electro-mechanical printing apparatus (also referred to as the print device), of a printer. The method begins with the step of receiving data that deflnes a page representation. A plurality of regions of thepage are selected, which regions contain at least a portion of the page . . . . ~
f ~
Q1~8~4 representation. In one aspect of the invention, separate data for each such region is identified corresponding to the portion of the page representation contained in that region. Data identified for at least one of the regions is then compressed, using at least one compression algorithm and stored. For producing the page representation after storing the compressed data, the compressed data is decompressed and transmitted to the visual-output device.
In another aspect of the invention, at least one compression factor and a plurality of compression algorithms are provided. The compression factor has a determinable value that is related to a reference value. A compression algorithm is then chosen based on the relationship of the determined value of the compression factor to the reference value.
More specifically, the preferred embodiment of the invention is an apparatus for printing a two-dimensional page representation composed potentially of text, graphic and image objects (object representations) individually, and in combination. A print device is responsive ~o raster data for printing a page containing the page representation. An input device, such as a personal computer or workstation, is used for inputting data defining the page representation. A program memory stores program instructions including a piurality of different algorithms for compressing the data associated with corresponding different representation types and their combinations. The selection of compression algorithms is based in part on balancing the compression factors of compression ratio, computational complexity, and visual quality. A processor is coupled to the input device, print device, program memory and a data memory for executing the stored program instructions.
The processor is responsive to the data input in the form of descriptive commands for identifying data for each of a plurality of ordered regions or bands containing collectively at least a portion, and preferably, all of the page representation. The data for each region corresponds to the portion of the page representation contained in that region. Some regions may not contain data. The descriptive commands, which are not necessarily band limited, are SPEClFiCATlON 3 .
,. . . . . .
4 ~ ~
converted into lists of primitive elements selected from a set of primitive elements. Each primitive element represents at least a portion of an object representation. These lists are referred to as display lists. There is preferably a display list for each region, although the display list could be for the entire 5 page, or for other defined regions.
The types (and combinations of types) of representations and boundaries (referred to as bounding boxes) of each type contained in each region are determined. The display list data associated with the determined types of representations for each region is rasterized into an uncompressed 10 band and then compressed using algorithms corresponding to the analysis of certain compression factors. Rasterizing refers generally to the conversion of high-level descriptive commands into rasters. Data associated with primitive elements is often already in raster form. However, for purposes of this discussion, rasterizing refers to the conversion of display list data for a region 15 into raster form without regard for whether or not the data associated with the corresponding primitive elements is already in raster form.
The compression factors may, and preferably do include compression goals specifying target visual quality, compression ratio, and computational complexity. Compression ratio re~ers generally to the bytes of memory required 20 to hold the compressed data relative to the bytes of memory required to hold the same data uncompressed. Additionally considered are such factors as the type of representation, content of individual boundin~ boxes, overall content ofthe page representation, estimated versus actual compression being achieved, and the number of passes or attempts made at compressing the data. Other 25 factors may also be used, and some of these factors may not be used in all situations. For example, the factors could be prioritized so that some are givenmore weight than others. As an extension of this, in certain situations some factors could be given no weight at all relative to other factors.
Some of these factors inherently have values that are readily determined.
30 Others relate to characteristics or features the state cf which is determined and ~ Q~82~
a value assigned accordingly. For instance, the three representation types of text, graphics and images could be assigned arbitrary respective identifier values 1, 2, and 3.
An algorithm, generally speaking, refers to a particular algorithm or 5 combination of algorithms with particular parameter values. Thus, a change in parameter values results in a change in the algorithm.
The compressed data is stored sequentially by region. In the preferred embodiment, when required for printing, data for a region is read and decompressed. Depending on the system configuration, the compressed data 10 may be transmitted to an external printer or stored pending requirement of the data by the print device. The data is then transmitted to the print device for printing. Producing data (display lists) for each region and defining the regions to conform to the sequential output of raster data to an output device minimizesthe number of times the data is decompressed, data added, and then 15 retcompressed. During this overall process ~data~ defining the page representation takes the form of descriptive commands, display lists and associated information, and raster data.
Data representative of the page representation is thus compressed and held in memory until such time as it is required by the print device for printing, 20 or until the content of a region is changed. The data for the regions are swapped in and out of the compressed-data memory using the selected compression and corresponding decompression algorithms, Uhereby reducing substantially the buffer memory requirements. This and other features and advantages of the present invention will be apparent from the following detailed ~ ~:
25 description of the preferred embodiment of the invention and as illustrated in the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of an apparatus made according to and for 30 practicing the method of the invention.
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FIG. 2 is an illustration of a page having different types ol two-dimensional representations FIG. 3 is a flow diagram summarizing a method of practicing the invention.
FIG. 4 is a flow diagram of step 58 of the diagram of FIG. 3.
FIG. 5 illustrates visually the development of non-intersecting bounding boxes from bounding boxes of different representation types that overlap according to the method of the diagram of FIG. 4.
FIG. 6 is a simplified graphic example of overlapping bounding boxes with identifying coordinates used in the method of the diagram of FIG. 4.
FIG. 7 is a flow diagram illustrating the development of non-intersecting bounding boxes corresponding to step 122 in FIG. 4.
FIG. 8 is a flow diagram of step 78 of the diagram of FIG. 3.
FIG. 9 is a flow diagram of step 80 of the diagram of FIG. 3.
FIG. 1û is a functional block diagram corresponding to the apparatus of FIG. 1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT AND METHOD
Referring initially to FIG. 1, a generalized visual-representation-generating 20 system made according to the present invention is shown generally at 10. It includes a visual information source 12 connected via a communication link 14 to an output-data generator 16. Generator 16 is connected to a visual-output device 18 via a communication link 20. As will be seen, various embodiments are realizable from this general structure. Output data generator 16 can be 25 resident within a host unit including source 12, can be resident within an output unit including visual-output device 18, or can be functionally split between a host unit and an output unit.
In the typical instance when data generalor 16 and output device 18 comprise a laser or other raster printer, information source 12 is a conventional 30 work station or other computer-based system, such as an Apple Macintosh or :
.. .. .
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IBM PC. The term print device is also used herein as an exar~ple of a visual-output device. In the preferred embodiment, this term applies to the electro-mechanical apparatus responsive to raster data for producing a printed page.
Generator 16 could also be incorporated in a computer or wofkstation, such as a computer-based system as has just been mentioned, programmed to function as described herein, for controlling a raster display or printing device, as hasalso been mentioned. Further, as is discussed with referenoe to FIG. 10, a host unit could generate and output the compressed data and an output unit could receive the compressed data, decompress it and transmit it to a resident visual-output device.
The preferred embodiment of the invention is thus directed to the printing of two-dimensional pixel representations. The general concepts are e~ually applicable to three (or more) dimensional representations to the extent they arerealizable in the system of FIG. 1.
Generator 16 includes an input\output controller 22 coupled to communication links 14 and 20. A conventional CPU (central processing unit) or processor 24 is coupled to controller 22, as well as to a read/write or random access memory (RAM) 26, ussd partially as a buffer memory, for storing data, and a read only memory ~ROM) 28 for storing pro~ram -instructions and fixed information, such as nonvariable data and compression and decompression algorithms, as is discussed in further det~1 with reference to FlGs. 3, 5, and 7-10. Any of a variety of conventional CPU's may be used, depending on the actual application. Further, other forms of hardware that -accomplish the same functions can be used.
FIG. 2 illustrates a page 30 having a page representation 34 that could be defined by data input by the input device using a conventional page-description language, such as the language available from A~obe Systems Incorporated known by the name PostScript. In the printer environment, as a PostScript file is created on source 12 (FIG. 1), objects can be created in any arbitrary order or fashion on a page. The objects are defined by one or mors .. , . ,. ~. .
; . - - : .
: . .. . ;.:- , . ~, , , . . , - :
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descriptive commands. As used herein, then, an ~'ob;~ct-defir,ing command" is the command or collection of commands that define en object.
Different compression schemes have been found to be pr'eferable for the different representation types of text, graphics, and images. For instanoe, the S human eye is often less sensitive to changes in images than to degradations insomething as well defined as text. Thus, technically lossy compressiorl schemes such as JPEG, when used at reduced levels of compression for images, can be visually lossless. Further, by the nature of graphics objects, some otherwise lossy schemes may be usable without compromising spatial 10 resolution. The LZW technique has been found to work well on text, runlength coding is effective for graphics and text/graphics combinations, and the JPEG
technique is useful for images. It is therefore advantageous to identify the different types of objects in a page representation.
Continuing to refer to FIG. 2, page 30 has defined boundaries 1~ represented by border line 32. The boundaries thus represent the maximum area wiShin which page representation 34 is to be produced. Page representation 34 includes the following objects on a background of a single color. A title or main heading 36 is formed of text in different c~lors (represented by the different tones). A subheading 38 identifies a text representation 40; a subheading 42 identifies a graphics representation 44; and a subheading 46 identifies an image representation 48. These subheadings are text representations in relatively large fonts and, along with text representation 40, are all a single color different than the background color. Text representation 40 is in a reduced font. Graphics representatlon 44 has grid identifiers 50 in the form of alphanumeric characters (text), and a bar chart section 52 composed of bars of different colors. Image representation 48 is simply an array of pixels of varying colors.
Page representation 34 incorporates separate examples of large and small text, graphics, and image representations or o~jects. In a more complex page representation various of the different objects could overlap. That is, they .
~. : . - ~ . ,, , -; .
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could be printed at least partially on a cornmon area. The preferred methocl of the present invention is designed to take such overlapping areas into consideration, as is discussed in greater detail below.
A generalized flow diagram chart of a process or method 54 according to 5 the invention is provided in FIG. 3. Processor 24 of FIG. 1 executes instructions to function as an interpreter that recognizes the PostScript descriptive commands input as page data from source 12, as is provided by step 56 in ~he flow diagram of FIG. 3. In the general method of the invention, the page description data is divided into at least one, and preferably R dMerent data 10 regions at step 58. The regions can be determined in advance, as is the case with the preferred embodiment and therefore be determined arbitrarily with reference to a particular page representation. They could also be determined dynamically for each page representation. Referring to FIG. 2, an example of a dynamic determination would be to divide the page into separate regions corresponding to title heading 36, text subheading 3~, text section 40, graphicssubheading 42, each of grid identifiers 50, bar chart section 52, image subheading 46 and image section 48. In the preferred embodiment of the invention, however, in which raster data is produced for printir~ a page, the page area is divided into a plurality of fixed regions in the form of parailel 20 bands. The bands are chosen and ordered to correspond to the generation of raster data for output to a print device, and is therefore related to the resolution and scan order of the output device.
Referring again to FIG. 2, page 30 is shown for purposes of illustration divided into sixteen bands 60-75. When it is time to print, data for band 60 is 25 read out and decompressed first and the data progresses sequentially through the bands until data for the last band 75 is output. These bands each correspond to multiple raster scans~ of the page and provide for ordering the data in a way that will make the data readily available for printing. An actual letter-size page having a resolution of 300 dpi may be divided into about 20 to 30 40 bands.
SPECIFICATION g 2 ~ 4 As has been mentioned, the present invention provides for a reduction in the amount of memory required through the use of compression techniques, as is represented by step 78 in FIG. 3. By compressing a rasterized version of the descriptive data of the page representation, according to the preferred 5 embodiment, and decompressing it as needed by the printer or dispiay, the amount of RAM needed may be drastically reduced.
This memory reduction is achieved by storing in the working RAM a compressed representation of what is conventionally stored uncompressed in a frame buffer. Raster data is created for one region at a time and stored 10 uncompressed in RAM 26. This data is then compressed and re-stored in F~M
26 until needed. The data for all the regions is ultimately processed in this way until da~a for essentially all the regions is compressed and stored. In the preferred embodiment of the present invention, as data for each region is requested for output (printing), it is decompressed and output to the output 15 device (print device), as represented by step 80 in FIG. 3.
By compressing the data for the regions in the reverse order required for output to the output device, the compression/decompression cycle of the last region may be avoided, since it can simply be rasterized and output directly.
Also, depending on the circumstances, the decompression algor-~hm typically 20 is, but may not be exactly the reverse of the compression algorithm. When the outpu~ (page printing) is completed, process 54 ends for that page.
The following description of this process is directed to processing data for a single page. It will be understood that multiple pages may also be processed at a time using a similar system, so that dmerent ones of the steps 25 take place simultaneously for various regions of the same or different pages.Step 58 is shown in further detail by the flow diagram of FIG. 4. High level descriptive (such as PostScript) commands are input into data generato 16 from a source 12 as shown in FIG. 1. As has been described, these commands define, usually in no particular order, where text, graphics, and 30 image objects appear. Some of the commands do not define a particular 8 2 ~
object. These commands may be directed to identifying locations on a page, what color to use, and the like. Text typically includes definitions of font andcharacter size, as well as character identifiers and other informalion, such as the color of the text. Graphics are defined by area fills and strokes of arb~rary 5 color, and images are usually provided by bit or byte patterns.
Referring again to FIG. 4, the first object-defining command is selected at step 82. The intersection of the obiect defined by the command with each of the R regions (bands) is then determined, as shown generally at 84. Iterative loop step 86 symbolizes the sequential determinations made for each region.
10 When the first region is selected, a determination is made at 88 as to whether the object described by the command intersects the region. If there is no intersection, the next region is selected at s~ep 86 and the determination repeated for that region.
If there is an intersection, primitive elements, collectively referred to as a 15 display list, are generated for the portion of the object in the region at step 90.
Primitive elements are basic object portions or ~building blocksR that, when combined, form a new definition of an object. Character masks are used to define text. Geometric shapes, such as trapezoids and run arrays (bit patterns) are both graphics primitive elements. Because of the random color and - 2~ intensity changes, images are defined by the actual image descriptions. In some instances, these primitive elements are stored in the display list indirectly via pointers. Preferably, a single display list is generated for each region. Ashas been mentioned, it would also be possible to have a single display list for a page with allocation of data to a region taking place as raster data for the 25 region is stored prior to compressing.
Each high level input object-defining command implicitly has a corresponding representation type, such as text, graphics or image. Other ways of classifying the object-defining commands may also be used. In this embodiment, the primitive element has an associated representation type 30 corresponding to this implicit type. A bounding box is also determined for each 2~4~2~
region in which a portion of an object exists. A representation type is assignedto each bounding box based on the associated primitive element type. In the preferred embodiment, the representation type is one of the three preferred types of text, graphics and image.
A bounding box is a defined area containing an object or object portion in the region. In an X-Y coordinate system, a bounding box is preferably a rectangle defined by the coordinates of the lower left and upper right corners.
Other definitions for bounding boxes, such as trapezoids, could also be used.
l~ere is thus potentially a single bounding box for each representation type in each region, referred to as a regional bounding box. As is discussed below, as an object is added to a region, the regional bounding box of the same type is preferably expanded to include the area of the new primitive element(s) and the display list for the region is updated, as represented by step 92.
Collecting only one text, one graphic and one image bounding box for each region sa~isfies a requirement of computational simplicity while processingthe primitive elements. However, it does so at the expense of lost local information. For example, if an ~a~ is marked on the left side of the region anda "b- is marked on the right side of the region, there would be a tex~ bounding ~; box that spans the width of the region although characters do not fill this entire span. Consequently, a logical extension of this invention would be to perform this information collection on a smaller region basis, such as having two or three regions across the width of a page. This wo~uld provide more local tracking of the objects in the regions. In general, as has been discussed, the page can be divided into any arbitrary regions.
FIG. 5 shows visually the development of bounding boxes. Bounding boxes are also referred to herein, in a general sense, as regions. Each bounding box identifies a specific region of a page in which an object, collection of objects, or portions thereof, exists. As was described with reference to page30 shown in FIG. 2, the selected regions can be set dynamically to correspond to the objects in each page representation. A bounding box is thus a specific ~` 2 1 ~
.
:
example of this concept. However, in the following d:~cussion, the term region refers to the bands as shown in FIG. 2 and not to bo!~nding boxes.
The leH-most representation in FIG. s illustrates a regional graphics bounding box 100 and a regional text bounding box 102. The text bounding 5 box was formed by combining all the bounding boxes (not shown) for characters 1û4 (t), 105 (e) and 106 (x). Bounding box 102 is enlarged by adding bounding box 107 associated with the addition of a new character 1û8 "t" to ~tex~, resulting in enlarged bounding box 110 shown in the center of FIG. 5 containing the word "text".
Referring again ~o FIG. 4, this process of building regional bounding boxes of each type continues until the descriptive command is processed for each region, or until intersection with all regions has been determined as described. After the last region is checked, a deterrr,ination is made at step 112 if there is another command. If there is, the next command is selected at step 114 and process 84 is repeated. If there are no other commands, then intersecting bounding boxes for each region are determined, as shown generally at 116.
In the discussion to follow, H will be seen that different compression algorithms are applied to the different types and combinations of types of 20 representations. The following procedure divides the bounding boxes into non-intersecting bounding boxes that are exclusively of a particular type or a particular combination of types. This allows different objects of different types to have the associated raster representation compressed wit'n different algorithms. During this procedure, the size of boun~lng boxes that contain a 25 combination of overlapping objects of different types are minimized.
As controlled by iterative loop 118, the regions are sequentially checked to see if the bounding boxes of the different types intersect, as shown in step 12û. If not, the next region is checked. If the bounding boxes do intersect, thebounding boxes for the region are divided at step 122 into non-intersecting 30 bounding boxes. This process is illustrated visually in the right illustration of . . .,: . . .
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FIG. 5 with shaded boxes representing different non-intersecting bounding boxes. These non-intersectiny bounding boxes may also be re~erred to as subregions. Regional bounding box 110 is divided into non-intersecting bounding boxes 124, 125 and 126. Similarly, regional graphics bounding box 100 is divided into non-intersecting bounding boxes 125, 128, and 129. Non-intersecting text bounding boxes 124 and 126 have only text representations in them. Non-intersecting graphics bounding boxes 128 and 129 have only graphics representations in them. Remaining bounding box 125 has a combination of both text and graphics representations, as noted in the figure.
FIG. 6 is a simplified representation of a combination of three different original bounding boxes 130, 132 and 134 in a region 136 of types text ~r), - graphics (G), and image (I), respectively, as shown. This figure does not represent the same bounding box configuration as FIG. 5, but is used to illustrate the method of dividing intersecting bounding boxes of all three representation types. In order to simplify the explanation, adjacent coordinate values are used and only represent relative pixel coordinates. Actual values aretypically much higher and are typically not adjacent. Bounding box 130 is defined by the lower left and upper right coordinates having the (~(, Y) values (0,2)(6,3). Similarly, bounding boxes 132 and 134 have the coordinate values (1,1)(2,4) and (3,0)(5,5), respectively. In order to delineate between adjacent bounding boxes, the pixels along the ieft and bottom boundaries are included in the bounding box and the pixels along the right and top boundaries are excluded. Thus, the upper right coordinate identifying each bounding box is not included in the bounding box.
The process of dividing these regional bounding boxes into non-intersecting bounding boxes may be thought of as a distilling operation. The method is illustrated in the flow diagram of FIG. 7 with reference to the chart of FIG. 6. Starting with step 140, the bounding box coordinates are listed and the Y coordinates are ordered from lowest to highest. This procedure may also be : 30 performed in reverse using the highest coordinates first instead of the lowest.
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In the following discussion, the reference to X and Y coordinates may be reversed and the results will be the same. In this case the Y coordinates are:
o, 1, 2, 3, 4 and 5. The two lowest Y coordinates (0 and 1) are selected initialiy, and the X coordinates that are associated with the selected Y coordinates are ordered during step 142. Thus, Y = 0,1 and X=3,5 as provided by bounding box 134 X coordinates 1 and 2 for Y = 1, which define the bonom boundary of bounding box 132, are not used since this forms the top of what would otherwise be a test box (1,0)(2,1). This top line is not included in the test box, so there is no intersection with bounding box 132.
The next two lowest X coordinates are selected initially, during step 144.
In this case there are only two X coordinates. A test is then made during step 146 to determine if lhe resulting test box is in one of the original bounding boxes. Test box (3,0)(5,1), the top of which is shown by a dotted line in FIG. 6, is in bounding box 134 and is identified as bounding box A,. The subscript I
refers to the bounding box type, which in this case is image. rnis representation type and the coordinates of bounding box A are stored during step 148.
If the test box is not in an original bounding box, it is ignored and step 148 bypassed. The next step 150 is a determination as to whether thsre are more X coordinates for the existing pair of Y coordinates, 0,1. If so the next two X coordinates would be 5 and whatever the next one is. Since there are no more X coordinates, a test is made at step 152 to determine ~ there are any more Y coordinates. If not, the distilling procedure is completed. However, in this example, we are just beginning. There being another Y, the procedure retùrns to step 142 and repeats the above steps for Y=1,2.
Rather than go through the process step-by-step verbally, the following table is used to show the various steps involved in identifying all the non-intersecting bounding boxes A through M.
Y ¦ X ¦TEST EIOX ¦ ID ¦ STORE? ¦ TYPE
0,1,2,3,4,5 . . . .
0,1 ; ' . _ 3,5 . I
3,5 13,0)(5.1) A YES _ 1,2 1,2,3,5 _ ' .
_ I
1,2 (1,1)(2,2) 8 YES
2,3 (2,1)(3,2) C NO
3,5 (3.1 ) (5,2) D YES
2,3 0,1,2,3,5,6 _, =
l 0,1 (0,2)(1,3) E YES T
l 1,2 (1,2)(2,3) F YES T,G
2,3 l2,2)t3,3) G YES T
3,S 13.2)(5.3) H YES T,l 5,6 (5,2)(6,3) l YES T
. 1 3,4 _ _ =
l 1,2,3,5 . . .
1,2 (1,3) (2~4) J YES G
2,3 (2,3) (3,4) K NO
.` 3,5 (3,3)(5.4) E YES _ ¦
4,5 3,5 _~ _ _ ~, 3,5 (3,4)(5.5) ~J YES l ~'' I _ _ ~ SPECIFICATION 16 , ., .. - . . :
2 1 ~
FIG. 10 is a functional block diagram of the pre'erred embodiment of system 10 shown in FIG. 1. As shown in FIG. 10 and as has been discussed, a descriptive command receiver 154 assigns display list objects to the incoming commands, divides the display list objects into regions, defines the regional 5 bounding boxes, and stores the resulting information by region in a por~ion ofRAM 26 referred to functionally as a working memory 156. A distilling process unit 158 then divides the regional bounding boxes as required into non-intersecting bounding boxes and stores it in memory 156 as has been described with reference to FlGs. 4-7. The regional bounding boxes are 10 preferably retained in case further processing is required in a region.
After dividing the regional bounding boxes into non-intersecting bounding boxes, the display list is "rasterized" for each region and compressed. Then, the compressed data is stored along with bounding box and representation type information, compression algorithm identifiers, and any compression 1~ parameters, as provided by step 78 shown in FIG. 3. This step is shown in further detail in FIG. 8. The compression algorithms are selected, by what is referred to as "consultant" 166 (FIG. 10), on the basis of the previously mentioned compression factors. For instance, high speed operation and high quality may be required. In such a printer, computationally simpler algorithms 20 and lower compression ratio requirements might be used. A~ternatively, lower speed, lower quality, and higher compression ratio requirements would allow for more computationally complex algorithms.
Some compression schemes, such as one-color encoding, two-color encoding, run-length encoding, and subsampling, are computationally simple.
25 They provide limited compression of visually active objects, particularly images.
However, with simple objects, very high compression is realized. More complex compression schemes, such as those conventionally known as L~W and JPEG, provide varying levels of compression, depending upon the data processed and the values assigned to parameters. The amount of compression is also 30 controlled by controlling the parameters associated with such schemes, as is ~ , .
r~~
8~
well known in the art. In some cases, then, it may ~ possible to obtain poor visual quality quickly or high quality slowly. The par~cular compression algorithms used are determined by the compression factors.
Combinations of these techniques can be us~d to achieve even different 5 levels of compression, computational complexity and visual qual ty. The characteristics of the contents of the bounding boxes may be identified to determine whether yet other techniques would be appropriate. If a given bounding box has, for example, a graphic representation, then perusal of it may show that it consists of only two different colors. For a continuous tone device, 10 a savings of 8-to-1 for each colorant is achieved by representing the pixel map of the bounding box with a one-bit-per-pixel map wi~hout sacrificing quality. Ifthe contents have a single color, it is sufficient to store only the color and bounding box information. The compression realized depends upon the size of the bounding box.
As another example, the local activity or rate of change in the content of a bounding box could be determined. If there is only slight activity, a runlength coder technique may be used. If it is highly active, ~e JPEG technique may be employed. Further, H a representation is only a sm~1 portion of a region, then the raster contents of the bounding boxes may be s,mply copied. This provides RAM savings by not saving a raster representation ~f the unmarked background. This is also desirable for some bouncl~g boxes that contain combinations of objects or representation types. Thus, copying the raster data associated with a bounding box may be an important compression algorithm for satisfying compression goals.
The initial selection by consultant 166 of a set of compression algorithms (a compression scheme) including at least one algonthm, for compressing the data is shown as step 160 in FIG. 8. An "algorithm- as used herein refers to an algorithm with specific parameter values. Thus, a change in parameter values results in a different algorithm and different parameter values result in a plurality - 30 of algorithms. Each time a compression scheme is selected, consultant 166 ':
., . ~, , , - ~ .:
, . .
- . - - . , 2~0~82~ ~
, may form an estimate of the amount of overall compression expected based upon the various compression algorithms selected and the content of the page representation. Alternatively, the algorithms may be selected based upon an estimated compression requirement.
An iterative loop defined by step 161 is used to progress serially through the regions. For each region, the display list is rasterized in step 162 by a rasSer generator 163 and stored uncompressed in an uncompressed" memory 164 (FIG. 10), as provided by step 162. A compression unit 165, using algorithms selected for the compression scheme, subject to rnodification by a ~consuitant" 166, shown in FIG. 10, based upon the current state of the relevantcompression factors, compresses, at step 167, the rasterized display list and stores it in a "compressed" memory 168 (FIG 10). RAM 26 of FIG. 1 includes functional memories 156, 164 and 168. Different compression algorithms may be used on data corresponding to different boundin3 boxes determined according to the relevant compression factors. The bounding box, representation type, algorithm identifiers, and parameter values used are storedwith the compressed data.
The current values of the compression factors are compared to the target values to determine if adjustments may be required at decision step 169.
If progress is adequate, data for the next region is obtained.
If consultant 166 determines in step 169 that progress toward achieving the target compression factors is inadequate, the extent of inadequacy relative to the proportion of the page representation compressed is used to determine at step 171 whether to simply update the compression scheme and continue, or whether to reprocess at least some of the data that is already compressed. If the decision is to update, then in step 172 the compression scheme is revised based upon the current state of the relevant compression factors. A revised estimate of the expected compression results based on actual and projected progress is also determined. A new region is then selected at step 161 and the process continues as has been described.
: . -.. . . ,,. ~, ,-. ~
., .
,~. ~ -, . ; , ., ,~. , If at step 171 a decision is made to reprocess the ex,s~ng data, then a revised compression scheme and an updated estimate of ex~ected compression are determined at step ~74, based upon the relevant compression factors for this situation. A loop process, shown generally at 176, is then followed to reprocess the previously compressed data. An t~eration control step 17~ is used to progress through all of the regions. A determination is made in step 180 as to whether data for the particular region is compressed, and if so, whether it is desirable to reprocess the corresponding data. For instance, if very little additional memory capac ty is needed, it may be sufficient to reprocess only the data for the last region that was compressed, or only reprocess the data for regions having large amounts of data. If it is not to be reprocessed, the next region is selected If it is to be reprooessed, the data for the region is decompressed at step 182 based on the algori;~ms used to compress it. 1 hen an algorithm ident~led in the new compression scheme, possibly modified based upon the current state of the compression factors, is used to recompress the data.
The recompressed data is again stored in cornpressed rnemory 168.
Progress is checked at step 184. If progress is determined to be adequate, the 3 data for the next region is processed. If progress is inadequate, then a decision is made at step 186 either to simply update the compression scheme - and continue processing data for the remaining regions, or to reprocess selectively the data for all of the regions. As with the procedure associated with step 171, if the decision is to update, then the compression scheme is updated and estimates revised at step 188, and processing is continued at iterative step178. If the decision is made to reprocess the data for a given region, then step174 is returned to and reprocessing method 176 is reinitiated.
Reprocessing method 176 is followed until all of the previously compressed data is reprocessed. Control then returns to iterative step 161 to process data for any additional regions. Compression process 78 continues until there is sufficient compression to store all of the data. ~here is preferably ., .
.~. , . .
.
^~
at least one compression scheme that guarantees t~at all of the data will be compressed enough to be stored in memory. By d~nition, during this process, only data associated with those areas of a pa~e on which ~marking" occurs is stored. Data associated with portions of a region where no marking occurs is S not stored. This provides an inherent compression, regardless of the use of specific compression algorithms on the stored data.
It is also possible for RAM 26 of FIG. 1 to run out of memory when generating the display lists during process 84 shown in FIG. 4. In such a case, the existing display lists are rasterized, compressed and stored following a procedure very similar to that described with reference to FIG. 8 until adequateprogress is achieved. Then display list generation is resumed for the unprocessed descriptive commands.
The outputting of data to the visual output deYice, shown generally as step 80 in FIG. 3, is shown in further detail in FIQ 9. Because the regions intowhich the page is divided correspond to the raster o~der for producing the visual output, the regions are sequentially output. This is represented by the iterative loop 190 shown in FIG. 9. For each region, tt~e data stored in compressed rnemory 168 is read, decompressed based upon the algorithm~s) used to compress it, and stored in uncompressed memory 164, as represented by step 192. The data is decompressed using the reverse of the compression ` algorithrn used to compress it, or a variation of n, depending upon existing conditions. For instance, in order to make raster da~a available to the print device, it may be necessary to modify the algorithm(s) to increase the speed at which the data is decompressed. At step 194 the r~ter data is read from memory 164 and output on communication link 20 to the visual-output device 18 under the control of an output controller 196. As has been mentioned, in the preferred embodiment, the output device prints the page representation on a hard copy page. It is possible to bypass the compress/decompress cycle if the last region processed is the first region required by the print device.
FIG. 10 also illustrates an alternative printer system 200 made according .
:-. .. . . : - . : .
, ~ .. ~ .
- ~; - ~, ;
21~L.~24 to the inven~ion. System 200 includes a host unit 202, such as a workstation, including sourcs 12 and a modified output-data generator 16'. Generator 16' includes the components of generator 16, except ou~put controller 196, and output controller 204 that transmits data from cornpressed mernory 168 to an output unit 206. The modified content of generator 16' is represented by the dash-dot lines excluding controiler 196 and including controller 204.
Output unit 206 includes an input controller 208 that receives the regional compressed and associated data from generator 16', and stores it in a compressed memory 210 similar to memory 168 in generator 16'. A
1~ decompression unit 212, providing the decompression function described for compression unit 165 of generator 16, when required for output, decompresses the data and forms the necessary raster data in an uncompressed memory 214.
An output controller 216, equivalent to controller 196 then transmits the rasterdata to a resident visual-output device 18.
In system 200, then, steps 56, 58 and 78 shown in FIG. 3 are provided by host unit 202, and step 80 is provided by output unit 206. Considering the variations in hardware that are thus possible, the respective components, such as of host unit 202 and output unit 206, are referred to jointly as "computer means", "memory means", Uprocessor means~ and the like.
In the preferred embodiment, RAM 26 of FIG. 1 is used as the working memory, the uncompressed memory, and the compressed memory. A working - memory also exists in conventional PostScript-based printers. The uncompressed memory stores data ~or a single region at a time. If a page is divided into forty regions, this is a small part of the total memory requirements.
The primary benefit of this invention is realized in reducing the size requirements of what is referred to as compressed memory 168. The size is directly proportional to the amount of compression desired relative to visual quality, and computational complexity. For instance, if a rninimum compression of 10:i is desired, the memory size is reduced accordingly. However, if a consistently higher quality visual output is desired, a 4:1 compression may be selected. The target compression then affects the b~lance between the compression goals of compression ratio, visual quali~y, and computationai complexity.
It will be understood that parallel processing of regional data can also be S used for distilling bounding boxes, compressing, storing, reading and printing.
As has been mentioned this allows for processing different parts of the data fora page at a time. This can be extended to also prooess data for different pages at the same time.
The division of a page into parallel regions or bands is not a requisite to the general aspects of the present invention. The method of the present invention can also be carried out in a non-band environment, such as the system sold by Adobe Systems Incorporated with the name Photoshop. As noted though, it is useful in the specific embodiment as part of a printer to operate in a banded environment. There are additional inherent benefits in this type of system. That is, one wants to minimize the number of times, during data processing and printing, that data has to be compressed and decompressed in order to generate the raster data required by the output device. The use of bands and associated display lists assures that the data required by the printer is available in the sequence needed.
As has been noted with regard to various features of the present invention, it will be apparent to one skilled in the art that variations in form and detail may be made in the preferred embodiment and method without varyin~
from the spirit and scope of the invention as defined in the claims or as interpreted under the doctrine of equivalents. The preferred embodiment and method are thus provided for purposes of explanation and illustration, but not limitation.
, i .~ .
2 1 ~
FIG. 10 is a functional block diagram of the pre'erred embodiment of system 10 shown in FIG. 1. As shown in FIG. 10 and as has been discussed, a descriptive command receiver 154 assigns display list objects to the incoming commands, divides the display list objects into regions, defines the regional 5 bounding boxes, and stores the resulting information by region in a por~ion ofRAM 26 referred to functionally as a working memory 156. A distilling process unit 158 then divides the regional bounding boxes as required into non-intersecting bounding boxes and stores it in memory 156 as has been described with reference to FlGs. 4-7. The regional bounding boxes are 10 preferably retained in case further processing is required in a region.
After dividing the regional bounding boxes into non-intersecting bounding boxes, the display list is "rasterized" for each region and compressed. Then, the compressed data is stored along with bounding box and representation type information, compression algorithm identifiers, and any compression 1~ parameters, as provided by step 78 shown in FIG. 3. This step is shown in further detail in FIG. 8. The compression algorithms are selected, by what is referred to as "consultant" 166 (FIG. 10), on the basis of the previously mentioned compression factors. For instance, high speed operation and high quality may be required. In such a printer, computationally simpler algorithms 20 and lower compression ratio requirements might be used. A~ternatively, lower speed, lower quality, and higher compression ratio requirements would allow for more computationally complex algorithms.
Some compression schemes, such as one-color encoding, two-color encoding, run-length encoding, and subsampling, are computationally simple.
25 They provide limited compression of visually active objects, particularly images.
However, with simple objects, very high compression is realized. More complex compression schemes, such as those conventionally known as L~W and JPEG, provide varying levels of compression, depending upon the data processed and the values assigned to parameters. The amount of compression is also 30 controlled by controlling the parameters associated with such schemes, as is ~ , .
r~~
8~
well known in the art. In some cases, then, it may ~ possible to obtain poor visual quality quickly or high quality slowly. The par~cular compression algorithms used are determined by the compression factors.
Combinations of these techniques can be us~d to achieve even different 5 levels of compression, computational complexity and visual qual ty. The characteristics of the contents of the bounding boxes may be identified to determine whether yet other techniques would be appropriate. If a given bounding box has, for example, a graphic representation, then perusal of it may show that it consists of only two different colors. For a continuous tone device, 10 a savings of 8-to-1 for each colorant is achieved by representing the pixel map of the bounding box with a one-bit-per-pixel map wi~hout sacrificing quality. Ifthe contents have a single color, it is sufficient to store only the color and bounding box information. The compression realized depends upon the size of the bounding box.
As another example, the local activity or rate of change in the content of a bounding box could be determined. If there is only slight activity, a runlength coder technique may be used. If it is highly active, ~e JPEG technique may be employed. Further, H a representation is only a sm~1 portion of a region, then the raster contents of the bounding boxes may be s,mply copied. This provides RAM savings by not saving a raster representation ~f the unmarked background. This is also desirable for some bouncl~g boxes that contain combinations of objects or representation types. Thus, copying the raster data associated with a bounding box may be an important compression algorithm for satisfying compression goals.
The initial selection by consultant 166 of a set of compression algorithms (a compression scheme) including at least one algonthm, for compressing the data is shown as step 160 in FIG. 8. An "algorithm- as used herein refers to an algorithm with specific parameter values. Thus, a change in parameter values results in a different algorithm and different parameter values result in a plurality - 30 of algorithms. Each time a compression scheme is selected, consultant 166 ':
., . ~, , , - ~ .:
, . .
- . - - . , 2~0~82~ ~
, may form an estimate of the amount of overall compression expected based upon the various compression algorithms selected and the content of the page representation. Alternatively, the algorithms may be selected based upon an estimated compression requirement.
An iterative loop defined by step 161 is used to progress serially through the regions. For each region, the display list is rasterized in step 162 by a rasSer generator 163 and stored uncompressed in an uncompressed" memory 164 (FIG. 10), as provided by step 162. A compression unit 165, using algorithms selected for the compression scheme, subject to rnodification by a ~consuitant" 166, shown in FIG. 10, based upon the current state of the relevantcompression factors, compresses, at step 167, the rasterized display list and stores it in a "compressed" memory 168 (FIG 10). RAM 26 of FIG. 1 includes functional memories 156, 164 and 168. Different compression algorithms may be used on data corresponding to different boundin3 boxes determined according to the relevant compression factors. The bounding box, representation type, algorithm identifiers, and parameter values used are storedwith the compressed data.
The current values of the compression factors are compared to the target values to determine if adjustments may be required at decision step 169.
If progress is adequate, data for the next region is obtained.
If consultant 166 determines in step 169 that progress toward achieving the target compression factors is inadequate, the extent of inadequacy relative to the proportion of the page representation compressed is used to determine at step 171 whether to simply update the compression scheme and continue, or whether to reprocess at least some of the data that is already compressed. If the decision is to update, then in step 172 the compression scheme is revised based upon the current state of the relevant compression factors. A revised estimate of the expected compression results based on actual and projected progress is also determined. A new region is then selected at step 161 and the process continues as has been described.
: . -.. . . ,,. ~, ,-. ~
., .
,~. ~ -, . ; , ., ,~. , If at step 171 a decision is made to reprocess the ex,s~ng data, then a revised compression scheme and an updated estimate of ex~ected compression are determined at step ~74, based upon the relevant compression factors for this situation. A loop process, shown generally at 176, is then followed to reprocess the previously compressed data. An t~eration control step 17~ is used to progress through all of the regions. A determination is made in step 180 as to whether data for the particular region is compressed, and if so, whether it is desirable to reprocess the corresponding data. For instance, if very little additional memory capac ty is needed, it may be sufficient to reprocess only the data for the last region that was compressed, or only reprocess the data for regions having large amounts of data. If it is not to be reprocessed, the next region is selected If it is to be reprooessed, the data for the region is decompressed at step 182 based on the algori;~ms used to compress it. 1 hen an algorithm ident~led in the new compression scheme, possibly modified based upon the current state of the compression factors, is used to recompress the data.
The recompressed data is again stored in cornpressed rnemory 168.
Progress is checked at step 184. If progress is determined to be adequate, the 3 data for the next region is processed. If progress is inadequate, then a decision is made at step 186 either to simply update the compression scheme - and continue processing data for the remaining regions, or to reprocess selectively the data for all of the regions. As with the procedure associated with step 171, if the decision is to update, then the compression scheme is updated and estimates revised at step 188, and processing is continued at iterative step178. If the decision is made to reprocess the data for a given region, then step174 is returned to and reprocessing method 176 is reinitiated.
Reprocessing method 176 is followed until all of the previously compressed data is reprocessed. Control then returns to iterative step 161 to process data for any additional regions. Compression process 78 continues until there is sufficient compression to store all of the data. ~here is preferably ., .
.~. , . .
.
^~
at least one compression scheme that guarantees t~at all of the data will be compressed enough to be stored in memory. By d~nition, during this process, only data associated with those areas of a pa~e on which ~marking" occurs is stored. Data associated with portions of a region where no marking occurs is S not stored. This provides an inherent compression, regardless of the use of specific compression algorithms on the stored data.
It is also possible for RAM 26 of FIG. 1 to run out of memory when generating the display lists during process 84 shown in FIG. 4. In such a case, the existing display lists are rasterized, compressed and stored following a procedure very similar to that described with reference to FIG. 8 until adequateprogress is achieved. Then display list generation is resumed for the unprocessed descriptive commands.
The outputting of data to the visual output deYice, shown generally as step 80 in FIG. 3, is shown in further detail in FIQ 9. Because the regions intowhich the page is divided correspond to the raster o~der for producing the visual output, the regions are sequentially output. This is represented by the iterative loop 190 shown in FIG. 9. For each region, tt~e data stored in compressed rnemory 168 is read, decompressed based upon the algorithm~s) used to compress it, and stored in uncompressed memory 164, as represented by step 192. The data is decompressed using the reverse of the compression ` algorithrn used to compress it, or a variation of n, depending upon existing conditions. For instance, in order to make raster da~a available to the print device, it may be necessary to modify the algorithm(s) to increase the speed at which the data is decompressed. At step 194 the r~ter data is read from memory 164 and output on communication link 20 to the visual-output device 18 under the control of an output controller 196. As has been mentioned, in the preferred embodiment, the output device prints the page representation on a hard copy page. It is possible to bypass the compress/decompress cycle if the last region processed is the first region required by the print device.
FIG. 10 also illustrates an alternative printer system 200 made according .
:-. .. . . : - . : .
, ~ .. ~ .
- ~; - ~, ;
21~L.~24 to the inven~ion. System 200 includes a host unit 202, such as a workstation, including sourcs 12 and a modified output-data generator 16'. Generator 16' includes the components of generator 16, except ou~put controller 196, and output controller 204 that transmits data from cornpressed mernory 168 to an output unit 206. The modified content of generator 16' is represented by the dash-dot lines excluding controiler 196 and including controller 204.
Output unit 206 includes an input controller 208 that receives the regional compressed and associated data from generator 16', and stores it in a compressed memory 210 similar to memory 168 in generator 16'. A
1~ decompression unit 212, providing the decompression function described for compression unit 165 of generator 16, when required for output, decompresses the data and forms the necessary raster data in an uncompressed memory 214.
An output controller 216, equivalent to controller 196 then transmits the rasterdata to a resident visual-output device 18.
In system 200, then, steps 56, 58 and 78 shown in FIG. 3 are provided by host unit 202, and step 80 is provided by output unit 206. Considering the variations in hardware that are thus possible, the respective components, such as of host unit 202 and output unit 206, are referred to jointly as "computer means", "memory means", Uprocessor means~ and the like.
In the preferred embodiment, RAM 26 of FIG. 1 is used as the working memory, the uncompressed memory, and the compressed memory. A working - memory also exists in conventional PostScript-based printers. The uncompressed memory stores data ~or a single region at a time. If a page is divided into forty regions, this is a small part of the total memory requirements.
The primary benefit of this invention is realized in reducing the size requirements of what is referred to as compressed memory 168. The size is directly proportional to the amount of compression desired relative to visual quality, and computational complexity. For instance, if a rninimum compression of 10:i is desired, the memory size is reduced accordingly. However, if a consistently higher quality visual output is desired, a 4:1 compression may be selected. The target compression then affects the b~lance between the compression goals of compression ratio, visual quali~y, and computationai complexity.
It will be understood that parallel processing of regional data can also be S used for distilling bounding boxes, compressing, storing, reading and printing.
As has been mentioned this allows for processing different parts of the data fora page at a time. This can be extended to also prooess data for different pages at the same time.
The division of a page into parallel regions or bands is not a requisite to the general aspects of the present invention. The method of the present invention can also be carried out in a non-band environment, such as the system sold by Adobe Systems Incorporated with the name Photoshop. As noted though, it is useful in the specific embodiment as part of a printer to operate in a banded environment. There are additional inherent benefits in this type of system. That is, one wants to minimize the number of times, during data processing and printing, that data has to be compressed and decompressed in order to generate the raster data required by the output device. The use of bands and associated display lists assures that the data required by the printer is available in the sequence needed.
As has been noted with regard to various features of the present invention, it will be apparent to one skilled in the art that variations in form and detail may be made in the preferred embodiment and method without varyin~
from the spirit and scope of the invention as defined in the claims or as interpreted under the doctrine of equivalents. The preferred embodiment and method are thus provided for purposes of explanation and illustration, but not limitation.
, i .~ .
Claims (53)
1. A method of generating data for producing a page representation, including at least two different types of representations, on a page by a visual-output device, comprising the steps of:
receiving data defining the page representation;
providing at least a first compression algorithm and a second algorithm for compressing data;
identifying separate data corresponding to at least one representation type;
selecting an algorithm corresponding to the identified at least one representation type;
compressing identified data corresponding to the identified at least one representation type with the selected algorithm;
storing the compressed data; and after storing the compressed data, decompressing the stored data, and transmitting the decompressed data to the visual-output device.
receiving data defining the page representation;
providing at least a first compression algorithm and a second algorithm for compressing data;
identifying separate data corresponding to at least one representation type;
selecting an algorithm corresponding to the identified at least one representation type;
compressing identified data corresponding to the identified at least one representation type with the selected algorithm;
storing the compressed data; and after storing the compressed data, decompressing the stored data, and transmitting the decompressed data to the visual-output device.
2. A method according to claim 1 wherein the types of the representations can be determined from the received data, and the step of identifying the at least one representation type further includes determining from the received data the at least one representation type.
3. A method according to claim 1 where the data identified for at least the determined at least one representation type has one of at least two identifiable characteristics; the method further comprising the step of determining the characteristic of the data identified for the determined at least one representation type, and wherein the step of selecting includes selecting analgorithm corresponding to the determined characteristic when the representation type is the determined at least one representation type, and the step of compressing includes compressing the data identified for the determined at least one representation type with the algorithm selected corresponding to the determined characteristic when the representation is the determined at least one representation type.
4. A method according to claim 1 further comprising the step of determining at least two types of representations; dividing at least a portion of the page representation into a plurality of regions with at least a first one of the regions containing at least a first one of the representation types and at least a second one of the regions containing at least a second one of the representation types; and identifying separate data for the at least a first one of the regions and the at least a second one of the regions; and wherein the step of selecting includes selecting compression algorithms for compressing the identified data corresponding to the at least first and second regions; and the step of compressing includes compressing the identified data for the at least first and second subregions according to the corresponding selected algorithms.
5. A method according to claim 4 wherein the step of providing includes providing the at least first and second algorithms as different algorithms, and the step of selecting includes selecting the at least first algorithm for compressing the identified data corresponding to the at least a first one of therepresentation types and selecting the at least second algorithm for compressing the identified data corresponding to the at least a second one of the representation types.
6. A method according to claim 5 where the at least two regions overlap in a common portion that contains the corresponding at least two representation types; and wherein the step of dividing the at least a portion ofthe page into regions further includes identifying the common portion; the step of selecting includes selecting at least one of the algorithms for compressing the identified data corresponding to the common portion, and the step of compressing includes compressing at least the identified data corresponding to the common portion according to the selected at least one algorithm.
7. A method of generating data for producing a page representation on a page by a visual-output device, comprising the steps of:
receiving data defining the page representation;
providing at least a first compression algorithm for compressing data;
dividing at least a portion of the page into at least one region containing collectively at least a portion of the page representation, with the at least a portion of the page that is divided into the at least one region having a maximum area, the at least a portion of the page representation contained in the at least one region occupying less area than the maximum area, and the at least one region occupying an area that is less than the maximum area;
identifying separate data for the at least one region corresponding to the portion of the page representation contained in that region;
selecting at least the first algorithm;
compressing identified data for the at least one region with the selected algorithm;
storing the compressed data; and after storing the compressed data, for the at least one region, decompressing the stored data, and transmitting the decompressed data to the visual-output device.
receiving data defining the page representation;
providing at least a first compression algorithm for compressing data;
dividing at least a portion of the page into at least one region containing collectively at least a portion of the page representation, with the at least a portion of the page that is divided into the at least one region having a maximum area, the at least a portion of the page representation contained in the at least one region occupying less area than the maximum area, and the at least one region occupying an area that is less than the maximum area;
identifying separate data for the at least one region corresponding to the portion of the page representation contained in that region;
selecting at least the first algorithm;
compressing identified data for the at least one region with the selected algorithm;
storing the compressed data; and after storing the compressed data, for the at least one region, decompressing the stored data, and transmitting the decompressed data to the visual-output device.
8. A method according to claim 7 where the page representation includes at least two different types of representations; and wherein the step of providing includes providing at least a second algorithm for compressing data;
the step of identifying includes identifying at least one representation type corresponding to data contained within the at least one region; the step of selecting includes selecting an algorithm corresponding to the identified at least one representation type; and the step of compressing includes compressing the data corresponding to the identified at least one representation type in the at least one region according to the selected algorithm corresponding to the identified at least one representation type.
the step of identifying includes identifying at least one representation type corresponding to data contained within the at least one region; the step of selecting includes selecting an algorithm corresponding to the identified at least one representation type; and the step of compressing includes compressing the data corresponding to the identified at least one representation type in the at least one region according to the selected algorithm corresponding to the identified at least one representation type.
9. A method according to claim 8 wherein the types of the representations can be determined from the received data, and the step of identifying the representation type further includes determining from the received data the at least one representation type of the data identified for the at least one region.
10. A method according to claim 8 where the data identified for the identified at least one representation type has one of at least two identifiablecharacteristics; the method further comprises the step of determining the characteristic of the data identified for the identified at least one representation type, and wherein the step of selecting includes selecting an algorithm corresponding to the determined characteristic when the at least one representation type is the identified representation type, and the step of compressing includes compressing the data identified for the identified at leastone representation type with the algorithm selected corresponding to the determined characteristic when the representation is the identified at least onerepresentation type.
11. A method according to claim 7 where the page representation includes at least two different types of representations, and wherein the step of providing includes providing at least a second compression algorithm for compressing data; and the step of identifying includes identifying data associated with at least two of the representation types for the at least one region; the method yet further comprising the step of dividing the at least one region into a plurality of subregions with at least one subregion containing at least a first one of the representation types and another of the subregions containing at least a second one of the representation types; and wherein the step of selecting includes selecting compression algorithms for compressing the identified data corresponding to the at least one and other subregions; and the step of compressing includes compressing the defining data for at least the one and other subregions according to the corresponding selected algorithms.
12. A method according to claim 11 wherein the step of selecting includes selecting the at least first algorithm for compressing the identified data corresponding to the at least a first one of the representation types and selecting the at least second algorithm different than the at least first algorithm for compressing the identified data corresponding to the at least a second one of the representation types.
13. A method according to claim 12 where the at least two subregions overlap, and wherein the step of dividing the at least one region into subregions further includes identifying a common portion of the at least two overlapping subregions that contains the representation types of the at least two overlapping subregions, the step of selecting includes selecting at least one ofthe algorithms for compressing the data corresponding to the common portion, and the step of compressing includes compressing at least the defining data corresponding to the common portion according to the selected at least one algorithm.
14. A method of generating data for producing a page representation on a page by a visual-output device, comprising the steps of:
receiving data defining the page representation;
providing a plurality of compression algorithms for compressing data, and at least one compression factor having a determinable value;
dividing at least a portion of the page into a plurality of regions containing collectively at least a portion of the page representation;
identifying separate data for at least one region corresponding to the portion of the page representation contained in that region;
determining the value of the at least one compression factor;
selecting at least a first of the compression algorithms if the at least one compression factor has a value that has a predetermined relationship to a first value;
compressing identified data for the at least one region with the selected algorithm;
storing the compressed data; and after storing the compressed data, for the at least one region, decompressing the stored data, and transmitting the decompressed data to the visual-output device.
receiving data defining the page representation;
providing a plurality of compression algorithms for compressing data, and at least one compression factor having a determinable value;
dividing at least a portion of the page into a plurality of regions containing collectively at least a portion of the page representation;
identifying separate data for at least one region corresponding to the portion of the page representation contained in that region;
determining the value of the at least one compression factor;
selecting at least a first of the compression algorithms if the at least one compression factor has a value that has a predetermined relationship to a first value;
compressing identified data for the at least one region with the selected algorithm;
storing the compressed data; and after storing the compressed data, for the at least one region, decompressing the stored data, and transmitting the decompressed data to the visual-output device.
15. A method according to claim 14 wherein at least one of the compression factors is a target compression ratio.
16. A method according to claim 14 wherein at least one of the compression factors is a target visual quality of the page representation.
17. A method according to claim 14 wherein at least one of the compression factors is a target computational complexity.
18. A method according to claim 14 wherein the page representation includes at least two representation types, and the method further comprises the step of determining at least one type of representation for the portion of the page representation defined by the data associated with the at least one region,and wherein at least one of the compression factors is the type of representation, and the step of selecting includes selecting at least the first compression algorithm if the determined representation type is a first type.
19. A method according to claim 14 wherein the portion of the page representation for at least the one region has one of two identifiable characteristics and at least one of the compression factors is the characteristic of the portion of the page representation in a region, and the method further comprises the step of determining the characteristic of the portion of the page representation for at least the one region, and the step of selecting includes selecting at least the first compression algorithm if the determined characteristic is the one characteristic.
20. A method according to claim 14 wherein the page representation includes a plurality of object representations and at least one of the compression factors is the proportion that an object representation occupies relative to the page representation, and the method further comprises the step of determining the proportion that an object representation occupies relative tothe page representation, and the step of selecting includes selecting at least the first compression algorithm H the proportion that an object representation that forms at least a portion of the page representation in the one region, has a value that has a predetermined relationship to a first value.
21. A method according to claim 14 wherein the step of providing the at least one compression factor includes providing a plurality of compression factors; and the step of selecting includes selecting at least the first compression algorithm if the at least one of the compression factors has a value that has a predetermined relationship to a first value.
22. A method according to claim 21 further comprising the step of prioritizing at least two of the compression factors, and wherein the step of selecting includes selecting a compression algorithm based upon the relative priority of the at least two of the compression factors.
23. A method according to claim 14 wherein the at least one compression factor has a target value and the actual value is determinable based on the step of compressing, the method including, after the step of compressing identified data for the at least one region, determining the actual value of the at least one compression factor, and if the actual value has a predetermined relationship to the target value, decompressing the compressed data for the at least one region, selecting at least one compression algorithm based on the relationship of the actual value to the target value, and recompressing the previously compressed data using the selected at least one compression algorithm.
24. A method according to claim 14 wherein the at least one compression factor has a target value and the actual value is determinable based on the step of compressing, the method including, after the step of compressing identified data for the at least one region, determining the actual value of the at least one compression factor, and if the actual value has a predetermined relationship to the target value, selecting at least a second compression algorithm different than the at least a first compression algorithm,based on the relationship of the actual value to the target value, and compressing at least a portion of the data identified for at least a second region with the at least a second compression algorithm.
25. A method of producing a page representation including at least two representation types on a page by a raster output device, the method comprising the steps of:
receiving data defining the page representation;
dividing the page into a plurality of contiguous regions containing collectively at least a portion of the page representation;
identifying separate data for each region corresponding to the portion of the page representation contained in that region;
determining at least one type of representation or combination of types of representations for the portion of the page representation defined by the data associated with each of the regions containing data;
rasterizing the identified data for each of the regions containing data;
providing a plurality of different algorithms for compressing the data associated with corresponding different representation types and combinations of representation types;
selecting algorithms corresponding to each of the determined representation types and combinations of representation types for each region;
compressing the rasterized data for each region with an algorithm corresponding to each of the determined types of representations for that region;
storing the compressed data for each region; and serially for each region, reading the stored data associated with the region, decompressing the read data, and transmitting the decompressed data to the raster output device.
receiving data defining the page representation;
dividing the page into a plurality of contiguous regions containing collectively at least a portion of the page representation;
identifying separate data for each region corresponding to the portion of the page representation contained in that region;
determining at least one type of representation or combination of types of representations for the portion of the page representation defined by the data associated with each of the regions containing data;
rasterizing the identified data for each of the regions containing data;
providing a plurality of different algorithms for compressing the data associated with corresponding different representation types and combinations of representation types;
selecting algorithms corresponding to each of the determined representation types and combinations of representation types for each region;
compressing the rasterized data for each region with an algorithm corresponding to each of the determined types of representations for that region;
storing the compressed data for each region; and serially for each region, reading the stored data associated with the region, decompressing the read data, and transmitting the decompressed data to the raster output device.
26. A method according to claim 25 where the data identified for at least one determined representation type for at least one region has one of at least two identifiable characteristics, the method further comprising the steps of determining the characteristic of the data identified for the at least one representation type determined for the at least one region, and wherein the stepof selecting includes selecting an algorithm corresponding to the determined characteristic when the determined representation type is the at least one representation type, and the step of compressing includes compressing the data identified for the determined at least one representation type with the algorithm selected corresponding to the determined characteristic of the data ofthe determined at least one representation type.
27. A method according to claim 25 wherein the step of determining includes determining at least two types of representation for at least one region;
the method further comprising the step of dividing the at least one region into a plurality of subregions with at least a first one of the subregions containing at least a first one of the representation types and at least a second one of the subregions containing at least a second one of the representation types; and wherein the step of selecting includes selecting compression algorithms for compressing the identified data corresponding to the at least first and second subregions; and the step of compressing includes compressing the defining data for the at least first and second subregions according to the correspondingselected algorithms.
the method further comprising the step of dividing the at least one region into a plurality of subregions with at least a first one of the subregions containing at least a first one of the representation types and at least a second one of the subregions containing at least a second one of the representation types; and wherein the step of selecting includes selecting compression algorithms for compressing the identified data corresponding to the at least first and second subregions; and the step of compressing includes compressing the defining data for the at least first and second subregions according to the correspondingselected algorithms.
28. A method according to claim 27 wherein the step of selecting includes selecting at least a first algorithm for compressing the identified data corresponding to the at least a first representation type and selecting at least a second algorithm different than the at least first algorithm for compressing theidentified data corresponding to the at least a second representation type.
29. A method according to claim 27 where at least the first and second subregions overlap in a common portion; and wherein the step of dividing the at least one region into subregions further includes identifying the common portion; the step of selecting includes selecting at least one of the algorithms for compressing the identified data corresponding to the common portion; and the step of compressing includes compressing at least the identified data corresponding to the common portion according to the selected at least one of the algorithms.
30. A method according to claim 27 wherein the portion of the page representation contained within the one region occupies less area than the area of the one region, and the step of dividing includes dividing the one region into the plurality of subregions containing the portion of the page representation contained in the one region, with the subregions colectively occupying an area that is less than the area of the one region.
31. A method according to claim 25 wherein the at least a portion of the page that is divided into regions has a maximum area and the at least a portion of the page representation contained in the regions occupies less area than the maximum area and the step of dividing includes dividing the at least a portion of the page into the plurality of regions so that the regions collectively occupy an area that is less than the maximum area.
32. A method according to claim 25 further comprising the steps of providing data defining a base set of primitive elements; and assigning for eachregion an assigned set of primitive elements selected from the base set and representing collectively the portion of the page representation in that region;and wherein the step of compressing comprises rasterizing and compressing the data corresponding to the assigned set of primitive elements for each region.
33. A method according to claim 32 further comprising the step of dividing each region into at least one subregion for each type of representationand for each combination of types of representations contained within that region.
34. A method according to claim 33 wherein representations of different types overlap in at least one of the regions and the step of dividing further includes dividing the at least one region into at least one combination subregion that contains different representation types.
35. A method according to claim 34 wherein the step of selecting includes selecting at least one algorithm corresponding to overlapping representations of different types; and the step of compressing includes compressing the data associated with the combination subregion according to the selected at least one algorithm.
36. A method according to claim 25 wherein the step of providing includes providing at least one compression factor having a determinable value;
the method further comprising, prior to the step of selecting, the step of determining the value of the at least one compression factor, and wherein the step of selecting includes selecting at least a first compression algorithm if the at least one compression factor has a value that has a predetermined relationship to a first value.
the method further comprising, prior to the step of selecting, the step of determining the value of the at least one compression factor, and wherein the step of selecting includes selecting at least a first compression algorithm if the at least one compression factor has a value that has a predetermined relationship to a first value.
37. A method according to claim 36 wherein at least one of the compression factors is a target compression ratio.
38. A method according to claim 36 wherein at least one of the compression factors is a target visual quality of the page representation.
39. A method according to claim 36 wherein at least one of the compression factors is a target computational complexity.
40. A method according to claim 36 wherein the page representation includes at least two representation types, and the method further comprises the step of determining at least one type of representation for the portion of the page representation defined by the data associated with the at least one region,and wherein at least one of the compression factors is the type of representation, and the step of selecting includes selecting at least the first compression algorithm if the determined representation type is a first type.
41. A method according to claim 36 wherein the portion of the page representation for at least one region has one of two identifiable characteristics and at least one of the compression factors is the characteristic of the portionof the page representation in a region, and the method further comprises the step of determining the characteristic of the portion of the page representationfor at least the one region, and the step of selecting includes selecting at least the first compression algorithm if the determined characteristic is the one characteristic.
42. A method according to claim 36 wherein the page representation includes a plurality of object representations and at least one of the compression factors is the proportion that an object representation occupies relative to the page representation, and the method further comprises the step of determining the proportion that an object representation occupies relative tothe page representation, and the step of selecting includes selecting at least the first compression algorithm if the proportion that an object representation thatforms at least a portion of the page representation in the one region, has a value that has a predetermined relationship to a first value.
43. A method according to claim 36 wherein the step of providing the at least one compression factor includes providing a plurality of compression factors; and the step of selecting includes selecting at least the first compression algorithm if the at least one of the compression factors has a value that has a predetermined relationship to a first value.
44. A method according to claim 43 further comprising the step of prioritizing at least two of the compression factors, and wherein the step of selecting includes selecting a compression algorithm based upon the relative priority of the at least two of the compression factors.
45. A method according to claim 36 wherein the at least one compression factor has a target value and the actual value is determinable based on the step of compressing, the method including, after the step of compressing identified data for at least one region, determining the actual value of the at least one compression factor, and if the actual value has a predetermined relationship to the target value, decompressing the compressed data for the at least one region, selecting at least one compression algorithm based on the relationship of the actual value to the target value, and recompressing the previously compressed data using the selected at least one compression algorithm.
46. A method according to claim 36 wherein the at least one compression factor has a target value and the actual value is determinable based on the step of compressing, the method including, after the step of compressing identified data for at least one region, determining the actual value of the at least one compression factor, and if the actual value has a predetermined relationship to the target value, selecting at least a second compression algorithm different than the at least a first compression algorithm,based on the relationship of the actual value to the target value, and compressing at least a portion of the data identified for at least a second region with the at least a second compression algorithm.
47. A method of printing a two-dimensional page representation on a page having a maximum area, using a print system having at least one data memory coupled to at least one data processor and a print device coupled to at least one of the data processors, the page representation including a combination of text, graphic and image representation types, the method comprising the steps of:
inputting into a processor data defining the page representation as a combination of the different types of representations;
dividing the page into a plurality of contiguous parallel bands containing collectively the page representation;
identifying separate data for each band corresponding to the portion of the page representation contained in that band;
rasterizing the assigned data for each band;
determining the types of representations and boundaries of each type of representation contained in each band;
assigning the data for each representation type in each band to a region of that band corresponding to the boundaries of the representation of that type in that band;
providing a plurality of different algorithms for compressing data associated with corresponding different representation types;
providing at least one compression factor other than the representation type, which compression factor has a determinable value;
determining the value of each of the at least one compression factor;
selecting algorithms corresponding to the value of the compression factor and to the determined representation types and combinations of representation types for each region;
compressing the rasterized data for each region of each band with the selected algorithms;
storing the compressed data and associated information identifying the bands, representation types and combinations of representation types, and algorithms used to compress the associated data; and sequentially for each band:
reading and decompressing the corresponding stored data; and transmitting sequentially the decompressed data to the print device for printing the page representation.
inputting into a processor data defining the page representation as a combination of the different types of representations;
dividing the page into a plurality of contiguous parallel bands containing collectively the page representation;
identifying separate data for each band corresponding to the portion of the page representation contained in that band;
rasterizing the assigned data for each band;
determining the types of representations and boundaries of each type of representation contained in each band;
assigning the data for each representation type in each band to a region of that band corresponding to the boundaries of the representation of that type in that band;
providing a plurality of different algorithms for compressing data associated with corresponding different representation types;
providing at least one compression factor other than the representation type, which compression factor has a determinable value;
determining the value of each of the at least one compression factor;
selecting algorithms corresponding to the value of the compression factor and to the determined representation types and combinations of representation types for each region;
compressing the rasterized data for each region of each band with the selected algorithms;
storing the compressed data and associated information identifying the bands, representation types and combinations of representation types, and algorithms used to compress the associated data; and sequentially for each band:
reading and decompressing the corresponding stored data; and transmitting sequentially the decompressed data to the print device for printing the page representation.
48. A method according to claim 47 further comprising the steps of providing data defining a set of primitive elements having known representations, with each primitive element representing a portion of the page representation; and the step of identifying further comprises assigning for eachband primitive elements representative of the portion of the page representationin that region; and the step of compressing comprises compressing the data corresponding to the assigned primitive elements in each region.
49. A method according to claim 47 wherein the regions of at least one band overlap and the step of dividing further includes dividing the regions of each band that overlap into at least one combination subregion corresponding to at least one combination of different representation types associated with the regions that overlap.
50. A method according to claim 49 wherein the step of selecting includes selecting at least one of the compression algorithms according to the at least one combination of different representation types; and the step of compressing includes compressing data associated with the at least one combination subregion according to the selected at least one of the compression algorithms.
51. A method according to claim 47 wherein the step of providing the compression factor includes providing a plurality of compression factors comprising a target compression ratio, a target visual quality of the page representation, and a target computational complexity; and the step of selectingincludes selecting at least a first compression algorithm if at least one of thecompression factors has a value that has a predetermined relationship to a firstvalue.
52. A system for producing a page representation comprising:
a raster output device;
input means for receiving data defining the page representation;
at least one data memory means for storing raster data representative of the page representation; and at least one computer means including program memory means for storing computer program instructions including a plurality of different algorithms for compressing data and at least one compression factor having a determinable value, and processing means coupled to the input means, the raster output device, the data memory means and the program memory means for executing the stored program instructions, the processing means being responsive to input data for (a) identifying separate data for each of a plurality of regions containing collectively the page representation, the data for each region corresponding to the portion of the page representation contained in thatregion; (b) determining the value of the at least one compression factor for thedata identified for at least one of the regions; (c) rasterizing the identified data for each region containing data; (d) selecting at least one compression algorithm for compressing the data identified for each region, including selecting at least one algorithm for the at least one of the regions corresponding to the value of the at least one compression factor; (e) compressing the data for each region containing data with the selected at least one algorithm; (f) storing thecompressed data for each region containing data; and (g) after compressing the data, serially, for each region, reading the stored data associated with theregion, decompressing the read data, and transmitting the decompressed data to the raster output device;
the raster output device being responsive to the decompressed data for producing the page representation.
a raster output device;
input means for receiving data defining the page representation;
at least one data memory means for storing raster data representative of the page representation; and at least one computer means including program memory means for storing computer program instructions including a plurality of different algorithms for compressing data and at least one compression factor having a determinable value, and processing means coupled to the input means, the raster output device, the data memory means and the program memory means for executing the stored program instructions, the processing means being responsive to input data for (a) identifying separate data for each of a plurality of regions containing collectively the page representation, the data for each region corresponding to the portion of the page representation contained in thatregion; (b) determining the value of the at least one compression factor for thedata identified for at least one of the regions; (c) rasterizing the identified data for each region containing data; (d) selecting at least one compression algorithm for compressing the data identified for each region, including selecting at least one algorithm for the at least one of the regions corresponding to the value of the at least one compression factor; (e) compressing the data for each region containing data with the selected at least one algorithm; (f) storing thecompressed data for each region containing data; and (g) after compressing the data, serially, for each region, reading the stored data associated with theregion, decompressing the read data, and transmitting the decompressed data to the raster output device;
the raster output device being responsive to the decompressed data for producing the page representation.
53. A system for printing a two-dimensional page representation on a page having a maximum area, the page representation including a combination of text, graphic and image representation types, the system comprising:
a print device;
input means for inputting data defining the page representation as a combination of different types of representations;
data memory means for storing data representative of the page representation; and computer means including program memory means for storing computer program instructions including a plurality of different algorithms for compressing the defining data associated with corresponding different representation types and instructions defining at least one compression factor in addition to representation type and having a value determinable in association with a page representation, and processing means coupled to the input means, print device, data memory means and program memory means for executing the stored program instructions, the processing means being responsive to input data for (a) identifying separate data for each of a plurality of adjacent parallel bandscontaining collectively the page representation, the data identified for each band corresponding to the portion of the page representation contained in that band;
(b) rasterizing the assigned data for each band; (c) determining the types of representations and boundaries of each type of representation contained in each band; (e) determining the value of each of the at least one compression factor; (f) assigning the data for each representation type in each band to a region of that band corresponding to the boundaries of the representation of that type in that band; (g) selecting at least one algorithm for compressing therasterized data for each region corresponding to the value of the at least one compression factor and to the determined representation type or combination of representation types; (h) compressing the rasterized data for each band with the selected algorithms; (f) storing the compressed data for each band and data identifying: the bands, the regions of each band, the determined representation type or combination of representation types of each region, and the algorithms used to compress the data associated with each region; and (g) after compressing the data, for each band, reading the corresponding stored data, decompressing the read data, and transmitting the decompressed data to the print device;
the print device being responsive to the transmitted data for printing the page representation.
a print device;
input means for inputting data defining the page representation as a combination of different types of representations;
data memory means for storing data representative of the page representation; and computer means including program memory means for storing computer program instructions including a plurality of different algorithms for compressing the defining data associated with corresponding different representation types and instructions defining at least one compression factor in addition to representation type and having a value determinable in association with a page representation, and processing means coupled to the input means, print device, data memory means and program memory means for executing the stored program instructions, the processing means being responsive to input data for (a) identifying separate data for each of a plurality of adjacent parallel bandscontaining collectively the page representation, the data identified for each band corresponding to the portion of the page representation contained in that band;
(b) rasterizing the assigned data for each band; (c) determining the types of representations and boundaries of each type of representation contained in each band; (e) determining the value of each of the at least one compression factor; (f) assigning the data for each representation type in each band to a region of that band corresponding to the boundaries of the representation of that type in that band; (g) selecting at least one algorithm for compressing therasterized data for each region corresponding to the value of the at least one compression factor and to the determined representation type or combination of representation types; (h) compressing the rasterized data for each band with the selected algorithms; (f) storing the compressed data for each band and data identifying: the bands, the regions of each band, the determined representation type or combination of representation types of each region, and the algorithms used to compress the data associated with each region; and (g) after compressing the data, for each band, reading the corresponding stored data, decompressing the read data, and transmitting the decompressed data to the print device;
the print device being responsive to the transmitted data for printing the page representation.
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Families Citing this family (162)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6336180B1 (en) | 1997-04-30 | 2002-01-01 | Canon Kabushiki Kaisha | Method, apparatus and system for managing virtual memory with virtual-physical mapping |
JP3135243B2 (en) * | 1989-11-28 | 2001-02-13 | キヤノン株式会社 | Image data transmission / reception method and apparatus used therefor |
US5225911A (en) * | 1991-05-07 | 1993-07-06 | Xerox Corporation | Means for combining data of different frequencies for a raster output device |
US5539865A (en) * | 1992-11-10 | 1996-07-23 | Adobe Systems, Inc. | Method and apparatus for processing data for a visual-output device with reduced buffer memory requirements |
US5638498A (en) * | 1992-11-10 | 1997-06-10 | Adobe Systems Incorporated | Method and apparatus for reducing storage requirements for display data |
IL106297A (en) * | 1993-07-09 | 1997-11-20 | Indigo C O C O Indigo Ltd | Page make-up system |
US6327043B1 (en) | 1994-05-18 | 2001-12-04 | Xerox Corporation | Object optimized printing system and method |
US5687303A (en) * | 1994-05-18 | 1997-11-11 | Xerox Corporation | Printer controller for object optimized printing |
US5512921A (en) * | 1994-06-22 | 1996-04-30 | Microsoft Corporation | Visual display system having low energy data storage subsystem with date compression capabilities, and method for operating same |
US5552898A (en) * | 1994-07-06 | 1996-09-03 | Agfa-Gevaert | Lossy and lossless compression in raster image processor |
AUPM822394A0 (en) * | 1994-09-16 | 1994-10-13 | Canon Inc. | Object based rendering system |
US7190284B1 (en) * | 1994-11-16 | 2007-03-13 | Dye Thomas A | Selective lossless, lossy, or no compression of data based on address range, data type, and/or requesting agent |
US6170047B1 (en) * | 1994-11-16 | 2001-01-02 | Interactive Silicon, Inc. | System and method for managing system memory and/or non-volatile memory using a memory controller with integrated compression and decompression capabilities |
US6002411A (en) * | 1994-11-16 | 1999-12-14 | Interactive Silicon, Inc. | Integrated video and memory controller with data processing and graphical processing capabilities |
JPH08212023A (en) * | 1994-12-02 | 1996-08-20 | Canon Inc | Printing control device and its method |
JPH08171384A (en) * | 1994-12-16 | 1996-07-02 | Canon Inc | Method and device for converting scanning |
JP3754468B2 (en) * | 1995-02-14 | 2006-03-15 | コニカミノルタビジネステクノロジーズ株式会社 | Image data processing method and image processing apparatus |
US5704020A (en) * | 1995-03-08 | 1997-12-30 | Ricoh Company, Ltd. | Page printer resolution converting method, and variable-length reversible compression process |
US5784570A (en) * | 1995-04-07 | 1998-07-21 | At&T Corp | Server for applying a recipient filter and compressing the input data stream based upon a set of at least one characteristics in a multiuser interactive virtual environment |
EP0770300A2 (en) * | 1995-04-12 | 1997-05-02 | Eastman Kodak Company | High capacity compressed document image storage for digital color printers |
US5682249A (en) * | 1995-05-11 | 1997-10-28 | Xerox Corporation | Method of encoding an image at full resolution for storing in a reduced image buffer |
US7715642B1 (en) * | 1995-06-06 | 2010-05-11 | Hewlett-Packard Development Company, L.P. | Bitmap image compressing |
AU5867696A (en) * | 1995-06-06 | 1996-12-24 | Apple Computer, Inc. | System and method for image generation using compression |
US5666487A (en) * | 1995-06-28 | 1997-09-09 | Bell Atlantic Network Services, Inc. | Network providing signals of different formats to a user by multplexing compressed broadband data with data of a different format into MPEG encoded data stream |
AU720541B2 (en) * | 1995-07-03 | 2000-06-01 | Electronics For Imaging, Inc. | Image rendering for page printers |
US5729668A (en) * | 1995-09-15 | 1998-03-17 | Hewlett-Packard Company | Optimized hardware compression and decompression architecture for use by an image processor in a laser printer |
US5727137A (en) * | 1995-11-01 | 1998-03-10 | Seiko Epson Corporation | Printer driver architecture for reducing band memory |
US5859958A (en) * | 1995-11-14 | 1999-01-12 | Apple Computer, Inc. | Compact representation of object slices for rendering raster graphics |
CA2190306A1 (en) * | 1995-11-20 | 1997-05-21 | Vadlamannati Venkateswar | Compression for multi-level screened images |
US5930813A (en) * | 1995-12-21 | 1999-07-27 | Adobe Systems Incorporated | Method and system for designating objects |
US5777677A (en) * | 1996-02-09 | 1998-07-07 | International Business Machines Corporation | Approximate MPEG decoder with compressed reference frames |
US5793937A (en) * | 1996-03-29 | 1998-08-11 | Peerless Systems Corporation | Fallback processing for page generation using memory reduction techniques |
US5726760A (en) * | 1996-04-03 | 1998-03-10 | Oce-Nederland, B.V. | Method and apparatus for converting image representation formats as well as an image production system provided with such an apparatus |
US6002847A (en) * | 1996-04-10 | 1999-12-14 | Eastman Kodak Company | High capacity compressed document image storage for digital color printers |
US6538764B2 (en) * | 1996-04-12 | 2003-03-25 | Canon Kabushiki Kaisha | Printing apparatus, information processing apparatus, data processing method for use in such an apparatus, and storage medium storing computer-readable program |
US5852711A (en) * | 1996-04-24 | 1998-12-22 | Hewlett-Packard Company | Efficient pattern use in printers |
WO1997044955A1 (en) * | 1996-05-17 | 1997-11-27 | Matsushita Electric Industrial Co., Ltd. | Data multiplexing method, method and device for reproducing multiplexed data, and recording medium containing the data multiplexed by said method |
US5630028A (en) * | 1996-05-28 | 1997-05-13 | Bowne & Co., Inc. | Method of representing graphic data using text |
US5864871A (en) * | 1996-06-04 | 1999-01-26 | Multex Systems | Information delivery system and method including on-line entitlements |
US5802518A (en) * | 1996-06-04 | 1998-09-01 | Multex Systems, Inc. | Information delivery system and method |
US5819271A (en) * | 1996-06-04 | 1998-10-06 | Multex Systems, Inc. | Corporate information communication and delivery system and method including entitlable hypertext links |
DE19623327A1 (en) * | 1996-06-12 | 1997-12-18 | Hell Ag Linotype | Process for processing objects on printed pages |
US6222886B1 (en) * | 1996-06-24 | 2001-04-24 | Kabushiki Kaisha Toshiba | Compression based reduced memory video decoder |
JPH1023271A (en) * | 1996-07-05 | 1998-01-23 | Canon Inc | Image-forming method and its device |
US5913018A (en) * | 1996-07-24 | 1999-06-15 | Adobe Systems Incorporated | Print band rendering system |
US5828814A (en) * | 1996-09-10 | 1998-10-27 | Moore Business Forms, Inc. | Reduced cost high resolution real time raster image processing system and method |
US5991542A (en) * | 1996-09-13 | 1999-11-23 | Apple Computer, Inc. | Storage volume handling system which utilizes disk images |
WO1998013787A1 (en) * | 1996-09-24 | 1998-04-02 | Colorage, Inc. | Adaptive block image compression |
US6269190B1 (en) * | 1996-09-24 | 2001-07-31 | Electronics For Imaging, Inc. | Computer system for processing images using a virtual frame buffer |
US5995724A (en) * | 1996-11-01 | 1999-11-30 | Mikkelsen; Carl | Image process system and process using personalization techniques |
US6167086A (en) * | 1996-12-10 | 2000-12-26 | Thomson Licensing S.A. | Overhead data processor in a memory efficient image processing system |
JP3204136B2 (en) * | 1996-12-13 | 2001-09-04 | 富士ゼロックス株式会社 | Image processing apparatus and compression processing method |
US6256347B1 (en) | 1996-12-17 | 2001-07-03 | Thomson Licensing S.A. | Pixel block compression apparatus in an image processing system |
US6621934B1 (en) | 1996-12-17 | 2003-09-16 | Thomson Licensing S.A. | Memory efficient compression apparatus in an image processing system |
US6020975A (en) * | 1996-12-20 | 2000-02-01 | Apple Computer, Inc. | System and method for accelerated data recompression |
US5982937A (en) * | 1996-12-24 | 1999-11-09 | Electronics For Imaging, Inc. | Apparatus and method for hybrid compression of raster data |
US6023556A (en) * | 1997-01-29 | 2000-02-08 | Gammagrapnx, Inc. | Processing print job image data |
US5803629A (en) * | 1997-03-14 | 1998-09-08 | Paul H. Neville | Method and apparatus for automatic, shape-based character spacing |
AUPO648397A0 (en) | 1997-04-30 | 1997-05-22 | Canon Information Systems Research Australia Pty Ltd | Improvements in multiprocessor architecture operation |
US6311258B1 (en) | 1997-04-03 | 2001-10-30 | Canon Kabushiki Kaisha | Data buffer apparatus and method for storing graphical data using data encoders and decoders |
US5999709A (en) * | 1997-04-18 | 1999-12-07 | Adobe Systems Incorporated | Printer memory boost |
US6289138B1 (en) | 1997-04-30 | 2001-09-11 | Canon Kabushiki Kaisha | General image processor |
US6707463B1 (en) | 1997-04-30 | 2004-03-16 | Canon Kabushiki Kaisha | Data normalization technique |
US6259456B1 (en) | 1997-04-30 | 2001-07-10 | Canon Kabushiki Kaisha | Data normalization techniques |
US6246396B1 (en) | 1997-04-30 | 2001-06-12 | Canon Kabushiki Kaisha | Cached color conversion method and apparatus |
AUPO647997A0 (en) | 1997-04-30 | 1997-05-22 | Canon Information Systems Research Australia Pty Ltd | Memory controller architecture |
US5870535A (en) * | 1997-05-12 | 1999-02-09 | Lexmark International, Inc. | Method and apparatus for building rasterized lines of bitmap data to be printed using a piecewise-linear direct memory access addressing mode of retrieving bitmap data line segments |
US6204933B1 (en) * | 1997-06-20 | 2001-03-20 | Hitachi, Ltd. | Information print system and image processing apparatus |
US6266419B1 (en) | 1997-07-03 | 2001-07-24 | At&T Corp. | Custom character-coding compression for encoding and watermarking media content |
US6134018A (en) * | 1997-09-26 | 2000-10-17 | Electronics For Imaging, Inc. | Method and apparatus for creating personalized documents that include variable data |
US5970221A (en) * | 1997-10-02 | 1999-10-19 | Lexmark International, Inc. | Printer with reduced memory |
US6298173B1 (en) * | 1997-10-03 | 2001-10-02 | Matsushita Electric Corporation Of America | Storage management system for document image database |
JPH11127340A (en) * | 1997-10-24 | 1999-05-11 | Fuji Xerox Co Ltd | Image processor and image processing method |
JPH11154240A (en) | 1997-11-20 | 1999-06-08 | Nintendo Co Ltd | Image producing device to produce image by using fetched image |
US6247011B1 (en) * | 1997-12-02 | 2001-06-12 | Digital-Net, Inc. | Computerized prepress authoring for document creation |
US6337747B1 (en) | 1998-01-29 | 2002-01-08 | Canon Kabushiki Kaisha | System to adaptively compress raster image data |
US6791711B1 (en) * | 1998-06-24 | 2004-09-14 | Canon Kabushiki Kaisha | Image processing method, image processing apparatus, and recording medium |
US6912311B2 (en) * | 1998-06-30 | 2005-06-28 | Flashpoint Technology, Inc. | Creation and use of complex image templates |
US20020093669A1 (en) * | 1998-08-28 | 2002-07-18 | Russell Campbell | Complexity extensions for band management in a printer page pipe |
US6429949B1 (en) | 1998-10-15 | 2002-08-06 | Electronics For Imaging, Inc. | Low memory printer controller |
US6192157B1 (en) * | 1998-10-27 | 2001-02-20 | Hewlett-Packard Company | Modifications of postscript adaptive data compression (ADC) for 3 plane, 8 bit color images, JPEG lossy compression, and variable Q factors |
US6435969B1 (en) | 1998-11-03 | 2002-08-20 | Nintendo Co., Ltd. | Portable game machine having image capture, manipulation and incorporation |
US6624761B2 (en) | 1998-12-11 | 2003-09-23 | Realtime Data, Llc | Content independent data compression method and system |
US6145069A (en) * | 1999-01-29 | 2000-11-07 | Interactive Silicon, Inc. | Parallel decompression and compression system and method for improving storage density and access speed for non-volatile memory and embedded memory devices |
US6885319B2 (en) * | 1999-01-29 | 2005-04-26 | Quickshift, Inc. | System and method for generating optimally compressed data from a plurality of data compression/decompression engines implementing different data compression algorithms |
US7129860B2 (en) * | 1999-01-29 | 2006-10-31 | Quickshift, Inc. | System and method for performing scalable embedded parallel data decompression |
US7538694B2 (en) * | 1999-01-29 | 2009-05-26 | Mossman Holdings Llc | Network device with improved storage density and access speed using compression techniques |
US6819271B2 (en) | 1999-01-29 | 2004-11-16 | Quickshift, Inc. | Parallel compression and decompression system and method having multiple parallel compression and decompression engines |
US6604158B1 (en) | 1999-03-11 | 2003-08-05 | Realtime Data, Llc | System and methods for accelerated data storage and retrieval |
US6601104B1 (en) | 1999-03-11 | 2003-07-29 | Realtime Data Llc | System and methods for accelerated data storage and retrieval |
US6330025B1 (en) * | 1999-05-10 | 2001-12-11 | Nice Systems Ltd. | Digital video logging system |
EP1109093A1 (en) * | 1999-12-14 | 2001-06-20 | Sun Microsystems, Inc. | Method and apparatus for printing transparent graphics |
US6490696B1 (en) | 1999-12-15 | 2002-12-03 | Electronics For Imaging, Inc. | System and method for printer output regression testing using display lists |
JP4424845B2 (en) * | 1999-12-20 | 2010-03-03 | 本田 正 | Image data compression method and decompression method |
FR2804231B1 (en) | 2000-01-25 | 2002-11-08 | Vistaprint Usa Inc | CENTRALIZED PRINTING OF LOW-VOLUME COMMERCIAL DOCUMENTS ON MACHINES PREVIOUSLY LIMITED TO VERY LARGE PRINTS |
EP1259887A4 (en) * | 2000-01-25 | 2003-08-13 | Vistaprint Usa Inc | Managing print jobs |
US6633314B1 (en) * | 2000-02-02 | 2003-10-14 | Raja Tuli | Portable high speed internet device integrating cellular telephone and palm top computer |
US20020115477A1 (en) * | 2001-02-13 | 2002-08-22 | Raja Singh | Portable high speed internet access device with scrolling |
US7356570B1 (en) | 2000-08-29 | 2008-04-08 | Raja Tuli | Portable high speed communication device |
US7068381B1 (en) * | 2000-02-02 | 2006-06-27 | Raja Tuli | Portable high speed internet access device |
US20010047473A1 (en) | 2000-02-03 | 2001-11-29 | Realtime Data, Llc | Systems and methods for computer initialization |
US6731814B2 (en) * | 2000-05-01 | 2004-05-04 | Xerox Corporation | Method for compressing digital documents with control of image quality and compression rate |
US6894686B2 (en) | 2000-05-16 | 2005-05-17 | Nintendo Co., Ltd. | System and method for automatically editing captured images for inclusion into 3D video game play |
US6762855B1 (en) * | 2000-07-07 | 2004-07-13 | Eastman Kodak Company | Variable speed printing system |
US7417568B2 (en) | 2000-10-03 | 2008-08-26 | Realtime Data Llc | System and method for data feed acceleration and encryption |
US9143546B2 (en) | 2000-10-03 | 2015-09-22 | Realtime Data Llc | System and method for data feed acceleration and encryption |
US8692695B2 (en) | 2000-10-03 | 2014-04-08 | Realtime Data, Llc | Methods for encoding and decoding data |
US7305360B1 (en) * | 2000-10-25 | 2007-12-04 | Thomson Financial Inc. | Electronic sales system |
US7330830B1 (en) | 2000-10-25 | 2008-02-12 | Thomson Financial Inc. | Distributed commerce system |
US7287089B1 (en) | 2000-10-25 | 2007-10-23 | Thomson Financial Inc. | Electronic commerce infrastructure system |
JP2002157108A (en) * | 2000-11-17 | 2002-05-31 | Canon Inc | Image processing method, storage medium, and image forming device |
US7386046B2 (en) | 2001-02-13 | 2008-06-10 | Realtime Data Llc | Bandwidth sensitive data compression and decompression |
US7142326B2 (en) * | 2001-05-16 | 2006-11-28 | Xerox Corporation | Method and apparatus for variable data document printing |
US7268910B2 (en) * | 2001-05-16 | 2007-09-11 | Agfa Corporation | Just-in-time raster image assembly |
JP3932379B2 (en) * | 2001-10-02 | 2007-06-20 | 株式会社日立製作所 | Image processing apparatus and image sensor |
US7068398B2 (en) * | 2001-11-07 | 2006-06-27 | International Business Machines Corporation | System and method for efficient tile generation from complex raster data |
US7043077B2 (en) * | 2001-11-07 | 2006-05-09 | International Business Machines Corporation | System and method for efficient compression of raster image data |
US6653954B2 (en) | 2001-11-07 | 2003-11-25 | International Business Machines Corporation | System and method for efficient data compression |
US6996774B2 (en) * | 2002-02-12 | 2006-02-07 | Accenture Global Services Gmbh | Display of data element indicia based on data types |
US7324229B2 (en) * | 2002-04-10 | 2008-01-29 | Texas Instruments Incorporated | Rendering in a printer using bands |
US7236528B1 (en) | 2002-05-31 | 2007-06-26 | Apple Inc. | System and method for processing time-based media |
US7158255B2 (en) * | 2002-06-18 | 2007-01-02 | Lexmark International, Inc. | Method for printing shingling print data |
US7254270B2 (en) * | 2002-07-09 | 2007-08-07 | Hewlett-Packard Development Company, L.P. | System and method for bounding and classifying regions within a graphical image |
US7437019B2 (en) * | 2002-07-18 | 2008-10-14 | Noritsu Koki Co., Ltd. | Apparatus and method for image processing, image processing program and recording medium storing the image processing program |
US7715640B2 (en) | 2002-11-05 | 2010-05-11 | Konica Minolta Business Technologies, Inc. | Image processing device, image processing method, image processing program and computer-readable recording medium on which the program is recorded |
US8176428B2 (en) | 2002-12-03 | 2012-05-08 | Datawind Net Access Corporation | Portable internet access device back page cache |
US7710602B2 (en) * | 2003-03-31 | 2010-05-04 | Sharp Laboratories Of America, Inc. | Systems and methods for context-based adaptive image processing using segmentation |
US7383269B2 (en) * | 2003-09-12 | 2008-06-03 | Accenture Global Services Gmbh | Navigating a software project repository |
US9614772B1 (en) | 2003-10-20 | 2017-04-04 | F5 Networks, Inc. | System and method for directing network traffic in tunneling applications |
KR100524076B1 (en) * | 2003-11-13 | 2005-10-26 | 삼성전자주식회사 | Apparatus for compressing and decompressing of data |
US8619310B2 (en) * | 2007-05-25 | 2013-12-31 | Kyocera Document Solutions, Inc. | Image forming apparatus |
US8305660B2 (en) | 2004-08-19 | 2012-11-06 | Xerox Corporation | Methods and systems achieving print uniformity using reduced memory or computational requirements |
US8024483B1 (en) | 2004-10-01 | 2011-09-20 | F5 Networks, Inc. | Selective compression for network connections |
US8660977B2 (en) * | 2005-02-04 | 2014-02-25 | Accenture Global Services Limited | Knowledge discovery tool relationship generation |
US7904411B2 (en) * | 2005-02-04 | 2011-03-08 | Accenture Global Services Limited | Knowledge discovery tool relationship generation |
US20060179026A1 (en) * | 2005-02-04 | 2006-08-10 | Bechtel Michael E | Knowledge discovery tool extraction and integration |
US20060179069A1 (en) | 2005-02-04 | 2006-08-10 | Bechtel Michael E | Knowledge discovery tool navigation |
JP4405419B2 (en) * | 2005-03-31 | 2010-01-27 | 株式会社東芝 | Screen transmitter |
US7783781B1 (en) | 2005-08-05 | 2010-08-24 | F5 Networks, Inc. | Adaptive compression |
US8533308B1 (en) | 2005-08-12 | 2013-09-10 | F5 Networks, Inc. | Network traffic management through protocol-configurable transaction processing |
US8275909B1 (en) | 2005-12-07 | 2012-09-25 | F5 Networks, Inc. | Adaptive compression |
US7882084B1 (en) | 2005-12-30 | 2011-02-01 | F5 Networks, Inc. | Compression of data transmitted over a network |
US7873065B1 (en) | 2006-02-01 | 2011-01-18 | F5 Networks, Inc. | Selectively enabling network packet concatenation based on metrics |
US8565088B1 (en) | 2006-02-01 | 2013-10-22 | F5 Networks, Inc. | Selectively enabling packet concatenation based on a transaction boundary |
US20070239897A1 (en) * | 2006-03-29 | 2007-10-11 | Rothman Michael A | Compressing or decompressing packet communications from diverse sources |
US7542155B2 (en) * | 2006-09-25 | 2009-06-02 | Vistaprint Technologies Limited | Preparation of aggregate jobs for production |
US9356824B1 (en) | 2006-09-29 | 2016-05-31 | F5 Networks, Inc. | Transparently cached network resources |
US7765176B2 (en) * | 2006-11-13 | 2010-07-27 | Accenture Global Services Gmbh | Knowledge discovery system with user interactive analysis view for analyzing and generating relationships |
US8417833B1 (en) | 2006-11-29 | 2013-04-09 | F5 Networks, Inc. | Metacodec for optimizing network data compression based on comparison of write and read rates |
US9106606B1 (en) | 2007-02-05 | 2015-08-11 | F5 Networks, Inc. | Method, intermediate device and computer program code for maintaining persistency |
US7688232B2 (en) * | 2007-03-27 | 2010-03-30 | Intel Corporation | Optimal selection of compression entries for compressing program instructions |
JP5032419B2 (en) * | 2008-08-27 | 2012-09-26 | 株式会社東芝 | Server, screen transmission method and computer program |
FI20095175A (en) | 2009-02-23 | 2010-08-24 | Anygraaf Oy | A method for utilizing raster image segmentation in image compression |
US20100325101A1 (en) * | 2009-06-19 | 2010-12-23 | Beal Alexander M | Marketing asset exchange |
JP5545050B2 (en) * | 2010-06-09 | 2014-07-09 | コニカミノルタ株式会社 | Image processing apparatus, program, and image processing method |
JP5335751B2 (en) * | 2010-09-30 | 2013-11-06 | 京セラドキュメントソリューションズ株式会社 | Image forming apparatus |
AU2010241218B2 (en) * | 2010-11-03 | 2013-10-31 | Canon Kabushiki Kaisha | Method, apparatus and system for associating an intermediate fill with a plurality of objects |
JP5777398B2 (en) * | 2011-05-13 | 2015-09-09 | キヤノン株式会社 | Image processing apparatus, image processing method and program for image processing apparatus |
JP2014078860A (en) * | 2012-10-11 | 2014-05-01 | Samsung Display Co Ltd | Compressor, driving device, display device, and compression method |
KR102114388B1 (en) * | 2013-10-18 | 2020-06-05 | 삼성전자주식회사 | Method and apparatus for compressing memory of electronic device |
JP6354360B2 (en) | 2014-06-11 | 2018-07-11 | ブラザー工業株式会社 | Conversion device |
KR20180067221A (en) * | 2016-12-12 | 2018-06-20 | 에이치피프린팅코리아 주식회사 | Host divice transmitting print data to printer and method for encoding print data by host device |
Family Cites Families (20)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5354135A (en) * | 1984-08-03 | 1994-10-11 | Canon Kabushiki Kaisha | Recorder and dot pattern control circuit |
US5276780A (en) * | 1987-03-03 | 1994-01-04 | Minolta Camera Kabushiki Kaisha | Filing system |
US5018078A (en) * | 1987-12-09 | 1991-05-21 | Fuji Photo Film Co., Ltd. | Apparatus and method for processing huge image information at high speed |
US5034804A (en) * | 1987-12-25 | 1991-07-23 | Kabushiki Kaisha Toshiba | Electronic still camera with various modes of data compression |
WO1990003272A1 (en) * | 1988-09-26 | 1990-04-05 | Oki Electric Industry Co., Ltd. | Compression and decompression method of dot matrix character |
US5272768A (en) * | 1989-02-21 | 1993-12-21 | Hewlett-Packard Company | Blank strip font compression method and device, and resulting stored, decompressible font |
DE3925913A1 (en) * | 1989-08-04 | 1991-02-07 | Siemens Ag | METHOD FOR DRIVING PRINTING ELEMENTS |
JP2647226B2 (en) * | 1990-03-23 | 1997-08-27 | 沖電気工業株式会社 | Dot pattern compression method and decompression method |
US5329616A (en) * | 1990-08-16 | 1994-07-12 | Canon Kabushiki Kaisha | Compressed image stores for high resolution computer graphics |
US5151949A (en) * | 1990-10-10 | 1992-09-29 | Fuji Xerox Co., Ltd. | System and method employing multiple predictor sets to compress image data having different portions |
US5208676A (en) * | 1990-12-04 | 1993-05-04 | Fuji Xerox Co., Ltd. | Image processing apparatus with data storage region management, memory space allocation in accordance with detected compression ratio of data |
JP3125304B2 (en) * | 1990-12-11 | 2001-01-15 | ミノルタ株式会社 | Printer |
JP2859450B2 (en) * | 1991-01-31 | 1999-02-17 | 富士写真フイルム株式会社 | Image recording apparatus and image recording method |
EP0506482B1 (en) * | 1991-03-29 | 1998-11-25 | Canon Kabushiki Kaisha | Image processing |
US5270728A (en) * | 1991-04-17 | 1993-12-14 | Hewlett-Packard Company | Raster imaging device speed-resolution product multiplying method and resulting pixel image data structure |
JPH04358288A (en) * | 1991-06-04 | 1992-12-11 | Fujitsu Ltd | Reducing printer |
US5150454A (en) * | 1991-10-16 | 1992-09-22 | Patrick Wood | Printing system and method |
JP3033628B2 (en) * | 1991-12-26 | 2000-04-17 | ブラザー工業株式会社 | Printer control device |
JPH05221030A (en) * | 1992-02-18 | 1993-08-31 | Brother Ind Ltd | Apparatus for controlling printing |
US5539865A (en) * | 1992-11-10 | 1996-07-23 | Adobe Systems, Inc. | Method and apparatus for processing data for a visual-output device with reduced buffer memory requirements |
-
1992
- 1992-11-10 US US07/974,204 patent/US5539865A/en not_active Expired - Lifetime
-
1993
- 1993-08-06 EP EP93306254A patent/EP0597571B1/en not_active Expired - Lifetime
- 1993-08-06 DE DE69331871T patent/DE69331871T2/en not_active Expired - Lifetime
- 1993-08-25 CA CA002104824A patent/CA2104824A1/en not_active Abandoned
- 1993-11-10 JP JP30331293A patent/JP3454552B2/en not_active Expired - Lifetime
-
1995
- 1995-06-06 US US08/467,792 patent/US5504842A/en not_active Expired - Lifetime
- 1995-06-06 US US08/470,737 patent/US5544290A/en not_active Expired - Lifetime
- 1995-06-06 US US08/486,133 patent/US5506944A/en not_active Expired - Lifetime
-
1996
- 1996-06-25 US US08/670,335 patent/US5949968A/en not_active Expired - Lifetime
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EP0597571A3 (en) | 1995-01-25 |
JP3454552B2 (en) | 2003-10-06 |
EP0597571B1 (en) | 2002-05-02 |
DE69331871T2 (en) | 2002-12-19 |
US5949968A (en) | 1999-09-07 |
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