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 |
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.
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