IMAGE DECODER, IMAGE DECODING METHOD, IMAGE DECODING PROGRAM, RECEIVER, RECEIVING METHOD AND RECEIVING PROGRAM

摘要

PROBLEM TO BE SOLVED: To provide an intra-prediction technique of a luminance signal and a color difference signal with a color difference format of 4:2:0.SOLUTION: A second encoded bit string decoding section 203 continuously decodes information on an intra-luminance prediction mode of a prediction block of a luminance signal and information on an intra-color difference prediction mode of a prediction block of a color difference signal from an encoded string of information on the intra-luminance prediction mode of four prediction blocks of the luminance signal and information on the intra-color difference prediction mode of one prediction block of the color difference signal. When an image signal is intra-predicted in a minimum decoding block unit which is previously set, an intra-prediction section 206 intra-predicts the color difference signal according to the decoded intra-color difference prediction mode in a prediction block unit of intra-prediction of the color difference signal in the minimum decoding block which is set in accordance with a color difference format when a division mode for dividing horizontally and vertically the luminance signal is set.