	US 7,580,580 B1
	Method for compression of two-color anti aliased images
Richard G. Fell, San Jose, Calif. (US); Thomas G. O'Neill, Mountain View, Calif. (US); and Jordan M. Slott, Durham, N.C. (US)
Assigned to Sun Microsystems, Inc., Santa Clara, Calif. (US)
Filed on Jul. 12, 2005, as Appl. No. 11/180,407.
Int. Cl. G06K 9/36 (2006.01); G06K 9/46 (2006.01); G09G 5/00 (2006.01); H04N 7/12 (2006.01); H04N 11/02 (2006.01); H04N 11/04 (2006.01)

U.S. Cl. 382—232 [382/236; 382/245; 382/269; 345/611; 375/240.01]

2 Claims

1. A method to compress two color anti-aliased images comprising:

providing an image;

determining if said image is a two-color anti-aliased image;

exiting said method to compress two color anti-aliased images if said image is not a two-color anti-aliased image;

determining a first base color and a second base color of said image if said image is determined to be a two-color anti-aliased image;

detecting whether a run of two or more pixels of said first color is present;

determining that a pixel is a transition pixel if it is not part of a run of two or more pixels of said first color;

storing and/or transmitting said transition pixel data if a run of two or more pixels of said first color is not present;

encoding said first color if a run of two or more pixels of said first color is present;

encoding the number of pixels in said run of two or more pixels of said first color;

storing and/or transmitting said encoding or said first color and said encoding of said the number of pixels in said run of two or more pixels of said first color;

detecting whether a run of two or more pixels of said second color is present;

encoding said second color if a run of two or more pixels of said first color is present;

encoding the number of pixels in said run of two or more pixels of said second color; and

storing and/or transmitting said encoding or said second color and said encoding of said the number of pixels in said run of two or more pixels of said second color.