WO2013149614A1

WO2013149614A1 - Method for recording images

Info

Publication number: WO2013149614A1
Application number: PCT/DE2013/100101
Authority: WO
Inventors: Bernhard Wigger
Original assignee: Bernhard Wigger
Priority date: 2012-04-04
Filing date: 2013-03-14
Publication date: 2013-10-10
Also published as: DE102012102962B3

Abstract

The aim of the invention is to provide to a method for recording images in which a spatial perception is produced. The invention also makes it possible to produce image recordings with a constant depth of field in large spatial regions. Said aim is achieved by means of a movable image recorder which is arranged such that it can be moved relative to a focusing device. Several image recordings are stored over a recording range, wherein based on a correlation check, only the pixels of each plane for which a correlation exists in a plane are stored. Partial images are thereby produced for each plane, which partial images can be displayed on a display, which can also move, or can be supplemented by combining the partial images to form an overall image having a consistent depth of field.

Description

PROCEDURE FOR IMAGE RECORDING

The present invention relates to a method for image recording by means of an image pickup which is displaced in a recording area either between single and double focal length or above twice the focal length of a focusing relative to this so that the focusing device in each relative position of the image sensor on a An image is generated in the associated image plane, with the image recorder sequentially storing an image or partial image generated on the image plane by means of the focusing device at a plurality of relative positions.

Such a method is already known from the document US 201 1/0229840 A1. This involves a method in which two telecentric lenses are moved relative to one another in such a way that different focal lengths are set and, as a result, image sequences can be recorded which are focused on respectively different parts of an object.

Similar image recording methods are widely known in the art. Also relevant with regard to the invention is the German patent application DE 10 2005 000 659 A1, which relates to an image recording system with a multi-stage optical unit. By means of such a multi-stage optical unit which either has a lens with different refractive indices and segments formed thereby, or alternatively has a material of the same refractive index but with differently thick subsegments, it is possible to make the focal length very simple, for example by turning the optical unit to adapt and thereby sharply map different spatial depths of an object space. Such a recording technique makes it possible in particular, due to the variable focal length of the optical unit to display sharply distant objects and thus to record a sequence of images for the realization of a spatial impression. In addition to this solution, many particularly stereoscopic methods are known from the state of the art, although they can produce a spatially acting recording, but require more special tools such as multicolored glasses and the like for the reproduction of such a recording. For example, a camera pair is used instead of a single camera for such a stereoscopic image, with the individual cameras of this camera pair being laterally offset from one another so as to imitate the viewing angle of a human observer. The two images, which are recorded by the individual cameras, can then be displayed color-coded one above the other, which then requires two-color glasses, so that each eye can only decrypt the color component which is intended for viewing by the respective eye , Other forms of display using so-called shutter glasses are also known in the art, which open and close the field of view of the two human eyes alternately at the rate at which the pictures provided for the respective eyes alternate on a display screen.

Beyond these solutions, however, reproduction methods are also known, for example from DE 100 43 272 A1 or also from US Pat. No. 6,005,608 A1, in which a screen is moved forwards and backwards periodically in a display area, with an associated one in each position on the screen Partial image is displayed. Explicitly, such an arrangement primarily serves to display images which have been recorded in layers in any case, in particular from computer resonance tomographs or magnetic resonance tomographs. However, such a method allows a spatial image impression, without the need for directly worn on the head means for viewing are required so that even several people can be independent of each other without such aids in the correct viewing direction the spatial image impression when viewing the screen. Since the use of a computer tomograph for the production of images outside the medical field is not feasible, and the aforementioned solution of DE 10 2005 000 659 A1 signifies a severe limitation of the spatial gradations, the present invention is based on the object, a To realize arbitrarily fine gradable recording technique, which allows a simple way recording with spatial effect.

This object is achieved by a method for image recording according to the features of claim 1. Useful embodiments of such a method can be taken from the subclaims.

According to the invention, a device is used for this purpose, which comprises an image sensor for image recording, which can be designed, for example, as a photochip. This has a photosensitive layer, which embodies the image plane on which the image is formed. In the beam path which hits the image sensor, a focusing device is arranged, wherein between the focusing device and image sensor, a relative displacement by a suitable drive, for example by a stepping motor, is made possible.

In this case, the arrangement provides as a first of two alternatives that there is a distance between the image recorder and the focusing device between single and double focal length in order to obtain a reducing effect, which can be used, for example, in a video camera or a camera or the like , The second alternative is that the distance between the image recorder and the focusing device is chosen to be greater than twice the focal length of the focusing device, so that a magnifying effect occurs which can be used, for example, in a microscope device.

Equivalently, it is considered that either the image sensor is moved toward and away from the focusing device, or else the focusing device is itself movable and moves forwards and backwards in front of the image sensor. can be moved down. Also, a superposition of the effects is expressly claimed by the present invention.

Proceeding from this, at each relative position to one another, which image recorder and focusing device occupy successively, an image or partial image is generated on the image recorder, which is stored together with the current relative position. A plurality of images, each of which is sharply focused for a shooting distance, is thus created within a moving period of the image pickup or the focusing device, respectively, in the case where the image pickup is moved both in the forward and the backward movement Focusing device is included, within half a period of motion. The further explanations basically relate to the use of a full period for recording a spatial image. In that regard, it is provided that the image sensor is moved periodically reversing relative to the focusing device, wherein within a period of the entire recording area is covered by this movement. It can be carried out either in a uniform motion, or in discrete steps, preferably a few hundred individual steps, wherein in the case of discrete individual steps, an image storage takes place in each case between the individual steps.

In the following it will be described how the method according to the invention for spatial image recording is made possible by eliminating from each image all pixels which do not belong to objects in its focused photographing range. For this purpose, the invention provides, in addition to each image, to store at least one focused auxiliary image recorded offset from the image, wherein the pixels correlating in a corresponding auxiliary image are determined for each image and then it is checked whether the pixels correlating with one another coincide with one another , In this case, it is checked in particular whether an equal brightness and a same color are present at the correlating pixels and only in the case of a match the respective pixel is stored on a picture. In the case of a missing or too low match, however, the pixel is discarded.

The correlations of the individual pixels can either be calculated or determined by a calibration. For such a calibration, a screen can be irradiated with a traveling light spot at the distances which are intended to provide focused images during a recording. The pixels hit by the light spot in both image planes are then a correlated pair. The required agreement in terms of brightness and color is determined by electronics as equality within a tolerance band. In this case, therefore, no digital match is required, but an at least substantial match, which is also due to the circumstance that the offset images possibly have a certain deviation even with correlated pixels due to the different perspectives.

Because of this tolerance consideration, it may happen that pixels are stored in different image planes, in which case the storage of a pixel which has the greatest match is maintained. Corresponding pixels in other, earlier or later images with a lesser agreement are rejected, so that in the end each pixel occurs in only one of the images taken within a period. Since, because of the increase in the magnification with the range of coverage, images located farther back are shown too small for individually focused images, a concentric extension of the individual images is successively increased from image to image, so that the individual partial images merge to form a seamless image. The required size of the stretch also depends on the distance from the player because of the central perspective of the viewer. Since, depending on the subject space considered, individual pixels may not correlate at all, the most posterior image may also be completely recorded and stored, with closer parts of the image masking the background image as needed.

In addition, an essential aspect of the invention is represented when the individual partial images are not reproduced in different layers which correspond to the spatial image, but are combined to form a common, two-dimensional image, which thereby obtains a continuous depth of field. In particular, in the microscopic field of application of the invention, this makes it possible, for example, in the microscopy of small minerals to solve the currently still existing enormous depth of focus problems. As a result, an image is achieved with a depth of focus that is practically the same in all image planes. Also for the usual photography this aspect is significant.

With regard to the calibration of such a microscopic device, a very small screen, e.g. CRT screen mounted in an image plane of the microscope and provided with a wandering luminous dot. For each luminous point of the recording system, the correlated luminous spot of the auxiliary system is then to be determined in an auxiliary picture. For this purpose, a photosensitive layer must be applied in the relevant object width. The correlation between two luminous dots is found when the same pixel of the photosensitive layer is hit by the luminous dots of both systems.

With regard to the correlation, in particular of the reducing systems, either a complete second auxiliary system can be set up, which is created from an additional auxiliary image sensor arranged adjacent to the image recorder and a correspondingly arranged auxiliary focusing device. The optical axes of the focusing device and the Hilfsfokussiereinrichtung are preferably parallel to each other, wherein the two devices are as close to each other. Alternatively, the optical axis of the imaging system, or the focusing device or the imaging device alone, may be minimally rotated so as to view the same object from a different angular perspective. Thus, alternately in the original and in the rotated position on the same image sensor, an image and an auxiliary image are recorded, and in turn the correlating points are determined.

The methods described here should equally be used for images that are made with light, as well as for the use of other electromagnetic radiation or waves or electrons can be used.

The invention described above will be explained in more detail below with reference to an embodiment.

Show it

Figure 1 shows the schematic structure of a recording device in a lateral, schematic representation, as well

Figure 2 shows the schematic structure of recording system and parallel

Auxiliary system in a schematic plan view from above.

FIG. 1 initially shows an image recorder 1, which is movably arranged along an optical axis 3 within a receiving region 6. The receiving area 6 is limited in this case by the distances of a simple focal length 4 and a double focal length 5 of a focusing device 2, which images an object located in a subject space 7 onto the image recorder 1.

Due to its mobility, the image sensor 1 passes through the receiving area 6, starting from the double focal length 5 up to the simple focal length 4. The movement takes place due to a composite with the image recorder 1. nen stepping motor, which allows a gradation of movement in several hundred steps. At each stop of the image sensor 1, the latter takes the currently displayed image onto which a light-sensitive layer assigned to the image sensor 1 is imaged by means of the focusing device 2 and stores it. As a result, a plurality of images is created, which can each only sharply map each other only a part of the subject space 7.

Therefore, an auxiliary device shown in Figure 2 is provided, which is formed essentially of a Hilfsfokussiereinrichtung 9 and a Hilfsbildaufnehmer 8. The auxiliary image pickup 8 is moved parallel to the image recorder 1 and picks up an image which is at least somewhat offset with respect to the image recorder 1.

The auxiliary device is used to determine a correlation between the pixels 13, 14 of the auxiliary image pickup 8 and the actually recorded pixels 12 of the image sensor 1, so that it can be determined which pixels 12 belong to real objects. If a point 10 in the object space corresponds to an object present there, pixels 12 of the image recorder 1 and the correlated pixel 13 of the auxiliary image recorder 8 will show the same brightness and color and pixel 1 2 will be stored.

If no object is present at point 10, the pixels 12 and 13 are struck by different, more distant objects of unfocused light, which shows no or less good agreement in brightness and color and thus is eliminated for pixel 12.

If an object is present instead of at point 10 of the object space 7 at point 11, then the pixel 12 is hit by its light, but since the correlated pixel 13 does not receive light from point 11, pixel 12 becomes the focusing device at the present distance of the image recorder 1 2 not saved. Only when this distance is set so that pixel 12 with pixel 14 correlates (displacement in Fig. 2 not shown), the object point 1 1 generate the same light at pixel 12 and correlated pixel 14 and pixel 12 is stored.

Thus described above is a method for image recording in which a spatial recording area can be covered by a relative movement between an image recorder and a focusing device, wherein only those image parts which correspond to a real object are regularly recorded in one of the layer images. These can either be reproduced in the reverse direction with the aid of a display device with a periodically reversing screen in order to create a spatial impression or, alternatively, after concentric stretching of the images to be magnified centrally, be combined to form an overall image which then has a consistently high depth of field.

REFERENCE TO LIST Imager

focusing

optical axis

simple focal length

double focal length

reception area

Object space

Hilfsbildaufnehmer

Hilfsfokussiereinrichtung

first point of interest

second point of interest

pixel

first correlating pixel

second correlating pixel

Claims

P A T E N T A N S P R E C H E

Method for image recording by means of an image recorder (1) which is displaced in a receiving region (6) either between single and double focal length (4, 5) or above twice the focal length (5) of a focusing device (2) relative thereto, in that the focusing device (2) generates an image in each relative position of the image recorder (1) on an image plane associated therewith, wherein the image recorder (1) successively generates an image or images generated on the image plane by means of the focusing device (2) at several relative positions Partial image stores,

characterized in that, in addition to each image, at least one auxiliary image staggered relative to the image is stored, the correlating pixels (13, 14) are determined for each image and corresponding auxiliary image, and it is checked whether these match, in particular as regards brightness and color, wherein, in the case of a match, the respective pixel (12) is stored and discarded in the event of a mismatch and the auxiliary image is stored by means of an auxiliary image pickup (8) located adjacent to the image receptor (1), which is on a common optical axis with an auxiliary focus - Siereinrichtung (9) is arranged, wherein the optical axes of the focusing siereinrichtung (2) and the Hilfsfokussiereinrichtung (9) parallel to each other.

A method according to claim 1, characterized in that the focusing device (2) and / or the image sensor (1) in the direction of an optical axis (3) of the focusing device (2) are movable.

Method according to one of the preceding claims, characterized in that the image recorder (1) is moved periodically reversing relative to the focusing device (2), wherein preferably the entire recording region (6) within a period at least once in discrete input. zelschritten, between each of which an image storage by the image sensor (1) takes place.

4. The method according to any one of the preceding claims, characterized in that the auxiliary image is recorded by the image sensor (1), wherein the optical axis of the focusing device (2) and / or image sensor (1) for this purpose at an angle to their orientation the shot of the picture is twisted. 5. Method according to claim 1, characterized in that at each pixel (12) a comparison is made with corresponding pixels of previously stored images of the same period and a pixel (12) is stored only if it is among all corresponding pixels of previous images same coincidence with the at least one auxiliary image, in particular in brightness and color, wherein in the case of storage of a pixel (12) all corresponding pixels of images of the same period are deleted. 6. The method according to any one of the preceding claims, characterized in that starting from the viewer from the furthest foreground image in the direction of the viewer from the farthest back image, a successively increasing concentric stretching of the images is made.

7. The method according to claim 6, characterized in that in a viewed from the viewer from the rearmost image regardless of the degree of agreement all the pixels (12) are stored, with closer parts of the picture cover this furthest posterior image if necessary.

8. The method according to any one of the preceding claims, characterized in that by the stored pixels (12) in each image of a ner resulting sub-images are combined to form an overall picture.

Method according to one of the preceding claims, in which light or another form of electromagnetic radiation or electrons are used for imaging.