IMAGE CODING AND DECODING USING MAPPING COEFFICIENTS CORRESPONDING TO CLASS INFORMATION OF PIXEL BLOCKS

An apparatus and method provides is configured such that a decoded image can be provided that is almost identical to the original image being encoded. In particular, corrected data of fewer pixels than the number of pixels for an original image is calculated by carrying out prescribed calculations using a pixel value for pixels of each block of the image and mapping coefficients that correspond to the class of the block. A predicted value for the original image is then estimated at a local decoder based on the corrected data. Then, at an error calculator, a prediction error for the original image for the predicted value is detected. At a mapping setting unit, a mapping coefficient corresponding to the class of the block is changed based on this prediction error. By repeating this process, mapping coefficients occurring when the prediction error is less than a prescribed threshold value are obtained. The number of pixels in the encoded image is thus minimized by including mapping coefficient in place of at least some of the image information.