US 6,983,074 B1
Data compression system and technique
Jon D. Clauson, Maple Grove, Minn. (US); and Christopher P. Hondl, Minneapolis, Minn. (US)
Assigned to Adobe Systems Incorporated, San Jose, Calif. (US)
Filed on Jun. 14, 2001, as Appl. No. 9/880,085.
Claims priority of provisional application 60/211493, filed on Jun. 14, 2000.
Int. Cl. G06K 9/36 (2006.01)
U.S. Cl. 382—244 60 Claims
OG exemplary drawing
 
1. A method for compressing an image, the method comprising:
receiving an image, the image being defined by pixels, each pixel having a true color, for decompression by a selected dictionary-based decompression technique;
receiving a color table that defines a mapping from true colors to index color values;
identifying a current pixel in the image, in which the current pixel is associated with exactly one previous current pixel;
identifying in a compression dictionary a set of zero or more candidate strings for the current pixel in the image, each candidate string corresponding to a string of pixels in a image, the last pixel of the string corresponding to the current pixel, and each candidate string approximately matching a corresponding image string; and
if the set of candidate strings for the current pixel is empty, selecting one of the candidate strings for the previous current pixel, and adding a code for the selected string to a compressed representation of the image.