Patent ID: 7391912
Filing Date: 2008-06-24
Classification: G06F,H03M,H04N

Abstract:
1. An image encoding system for compressing image data representing plural pixels of plural nonzero image tones, the system comprising: a pixel-designator configured to designate a current pixel to be encoded; an image-tone context-pixel identifier configured to identify, within a basic context region that includes multiple context pixels that are adjacent the current pixel, each of the context pixels having an image tone, the pattern of unique image tones among the context pixels in the context region; a non-local-trend identifier being configured to identify, within an extended context region that includes the basic context region, a non-local trend within the context pixels; a state assigner configured to assign a state according to identifications made within the basic and extended context regions; and a coder configured to perform adaptive entropy coding of the current pixel with reference to the state of the context region.