US 7,321,697 B2
Block-based, adaptive, lossless image coder
Subramania Sudharsanan, Union City, Calif. (US); and Parthasarathy Sriram, San Jose, Calif. (US)
Assigned to Sun Microsystems, Inc., Santa Clara, Calif. (US)
Filed on Oct. 08, 2003, as Appl. No. 10/682,550.
Application 10/682550 is a division of application No. 09/560440, filed on Apr. 28, 2000, granted, now 6,654,503.
Prior Publication US 2004/0071356 A1, Apr. 15, 2004
Int. Cl. G06K 9/36 (2006.01)
U.S. Cl. 382—244  [382/238] 12 Claims
OG exemplary drawing
 
1. A method for lossless coding of an image, the method comprising:
receiving and analyzing a data block representing pixel values for at least part of a digital image;
when all values in the block are the same, providing a dc predictor representing a constant pixel value for all pixels in the block;
when all values in the block are not the same, providing a selected set of non-dc predictor coefficients and providing predicted values for the pixels in the block;
forming and issuing a difference value between pixel value and predicted pixel value for each pixel in the block; and
receiving the pixel values, the predicted pixel values and the difference values, and forming and issuing a block of compressed values representing the pixel values for the block.