INTRA-PREDICTION CODING METHOD, INTRA-PREDICTION DECODING METHOD, INTRA-PREDICTION ENCODER, INTRA-PREDICTION DECODER, THEIR PROGRAM AND RECORDING MEDIUM RECORDING THEM

摘要

PROBLEM TO BE SOLVED: To improve subjective image quality and coding efficiency, by using closer decoded pixels in intra-prediction processing.SOLUTION: An intra-prediction generating a prediction signal in the same screen has a step for setting a reference pixel signal from a decoded pixel signal, a step for acquiring prediction mode identification information for identifying an intra-prediction mode, a step for generating a prediction signal based on the reference pixel signal and prediction mode identification information, a step performing determination for correcting the prediction signal by using a reference pixel of closer distance to a pixel becoming a prediction object, in the intra-prediction mode specified by the prediction mode identification information, and a step for correcting the prediction signal thus generated depending on the determination results. In the step performing determination, a correction range of the prediction object pixel is determined from parameters indicating the shape of a function defined with a decoded pixel, adjacent to the top left of the prediction object block, as an origin.SELECTED DRAWING: Figure 1