Patent ID: 7912304

Claim:
A display panel driver, comprising: a compression circuit configured to, when receiving image data of four pixels which are arrayed in two rows and two columns or in one row and four columns to constitute a target block, generate compressed image data corresponding to said target block by compressing said image data; an image memory configured to store said compressed image data; a decompression circuit configured to generate decompressed image data by decompressing said compressed image data reading from said image memory; and a drive circuit configured to drive a display panel in response to said decompressed image data, wherein said compression circuit includes: a plurality of pixel compression portions; and a form recognition portion, wherein said plurality of pixel compression portions include: a first pixel compression portion which calculates a first representative value corresponding to image data of said four pixels and puts said first representative value in said compressed image data, a second pixel compression portion which calculates a second representative value corresponding to image data of two pixels of said four pixels and puts said second representative value in said compressed image data, a third pixel compression portion which calculates a first bit plane reduced data by performing a bit plane reduction process independently on image data of each of said four pixels and puts said first bit plane reduced data in said compressed image data, and wherein said form recognition portion selects one of said plurality of pixel compression portions based on correlations among said image data determined for all possible combinations of two pixels selected from said four pixels of said target block.