Patent ID: 7433522

Claim:
An image encoding apparatus, comprising: a typical prediction unit for storing input image data, and performing typical predication in JBIG encoding of said input image data coding of said input image data, wherein the typical prediction unit includes; an auxiliary line buffer for retrieving said input image data via a first Direct Memory access (DMA) channel and storing said input image data; a line buffer for storing said image data of an immediately above line repeatedly read out from said auxiliary line buffer which has a size being a part of the line buffer; and a comparator for detecting by comparison between said auxiliary line buffer and said line buffer whether all pixels of said input image data match said image data of the immediately above line repeatedly read out from said auxiliary line buffer; a ping-pong buffer unit which has a first memory and a second memory, each having plural line memories for sequentially updating and storing said image data into corresponding addresses of said plural line memories via a second DMA channel, and generating a template; an encoding unit for reading out said image data stored in said ping-pong buffer unit, and performing adaptive arithmetic encoding on said image data and outputting encoded image data via a third DMA channel; and a control unit for controlling access to said ping-pong buffer unit between said typical prediction unit and said encoding unit.