Patent ID: 7668383
Filing Date: 2010-02-23
Classification: H04N

Abstract:
1. An image processing device comprising a first image processor for compressing data capacity of input image data of a raster image to output compressed data of the raster image, a memory for storing the compressed data, and a second image processor for decompressing compressed data read out of the memory to output decompressed output image data, the first image processor including: a reversible coder for dividing the input image data into a plurality of areas including a plurality of pixels and representing the input image data by representative value data as a gradation component of a common part of the pixels within each area and difference data as a difference between input gradation data of each pixel and the representative value data to execute a data conversion; and a bit plane compressor for executing a multi-valued dither processing of the difference data on the basis of a two-dimensional dither matrix to reduce a bit plane number of the difference data to obtain compressed difference data, the second image processor including: a bit plane decompressor for executing a bit addition processing of the compressed difference data read out of the memory on the basis of the two-dimensional dither matrix to obtain output difference data; and a reversible decoder for adding the representative value data to the output difference data to execute a data conversion to output image data, the compressed data including the representative value data and the compressed difference data.