Image encoding method and apparatus, image decoding method and apparatus, image processing apparatus, image formation apparatus, and computer-executable programs

摘要

Image data is encoded using a block consisting of a plurality of pixels as a unit of processing. A statistics section extracts statistical information for each pixel value, from a plurality of encoded blocks adjacent to an encoding target block, at each corresponding position within the respective blocks. An encoding processing section performs encoding on the encoding target block using the statistical information extracted by the statistics section. The encoding processing section comprises a prediction section that predicts a value of an encoding target pixel from the selected reference pixel based on the statistical information, a comparison section that detects an error between the predicted value and the value of the encoding target pixel, and an encoding section that performs entropy encoding on the prediction error.