(12) United States Patent ao) Patent No.: us 6,567,534 Bi
Rhoads (45) Date of Patent: *May 20,2003
(54) METHODS AND SYSTEMS FOR
WATERMARK PROCESSING OF LINE ART
IMAGES
(75) Inventor: Geoffrey B. Rhoads, West Linn, OR
(US)
(73) Assignee: Digimarc Corporation, Tualatin, OR (US)
( * ) Notice: Subject to any disclaimer, the term of this patent is extended or adjusted under 35 U.S.C. 154(b) by 277 days.
This patent is subject to a terminal disclaimer.
(21) Appl. No.: 09/626,985
(22) Filed: Jul. 27, 2000
Related U.S. Application Data
(60) Division of application No. 09/074,034, filed on May 6, 1998, now Pat. No. 6,449,377, which is a continuation-inpart of application No. 08/438,159, filed on May 8, 1995, now Pat. No. 5,850,481.
(60) Provisional application No. 60/082,228, filed on Apr. 16, 1998.
(51) Int. C I. I104K 1 00
(52) U.S. CI 382/100; 382/135
(58) Field of Search 382/100, 135,
382/232; 713/176; 380/210, 252, 287, 51, 54; 283/72, 85, 113, 901, 902
(56) References Cited
U.S. PATENT DOCUMENTS
4,660,859 A * 4/1987 Natesh 283/70
5,374,976 A * 12/1994 Spannenburg 355/201
5,772,249 A 6/1998 Guex et al.
5,838,814 A * 11/1998 Moore 382/115
5,843,564 A * 12/1998 Gasper et al 428/211
6,081,345 A * 6/2000 Curry 358/1.9
6,086,706 A 7/2000 Brassil et al 156/277
6,104,812 A * 8/2000 Koltai et al 380/51
FOREIGN PATENT DOCUMENTS
DE 29 43 436 Al * 5/1981 G06K/19/06
WO WO 95/26274 Al * 10/1995 B42D/15/10
OTHER PUBLICATIONS
Gruhl et al., "Information Hiding to Foil the Casual Counterfeiter, "Proc. 2nd Int'l Workshop on Information Hiding, Apr. 14-17, 1998, pp. 1-15.*
Boland, "Watermarking Digital Images for Copyright Protection," Fifth International Conf. on Image Processing and Its Applications, Conf. Publ. No. 410, pp. 326-330, 1995.
Gruhl, "Information Hiding to Foil the Casual Counterfeiter," Proc. 2d Information Hiding Workshop, LNCS vol. 1525, pp. 1-15, Apr., 1998.
* cited by examiner
Primary Examiner—Andrew W. Johns
(74) Attorney, Agent, or Firm—William Y. Conwell;
Digimarc Corporation
(57) ABSTRACT
Binary data is embedded in banknote artwork, permitting later recovery by, and control of, compliant devices that may encounter banknote image data, such as photocopiers, scanners, and printers. One embedding method involves providing nominal line art for the banknote, and imposing a virtual grid of points over the art, thereby defining plural regions. The luminance of at least certain of these regions is changed to effect encoding of the binary data. The luminance may be changed, e.g., by changing the width or spacing of the artwork lines, or by introducing new lines into the artwork.
8 Claims, 3 Drawing Sheets
