| 摘要 |
<P>PROBLEM TO BE SOLVED: To solve the problem of intra-prediction mode encoding in which the same probability model is set to all blocks causing a low efficiency. <P>SOLUTION: A predicted direction difference calculation section 604 calculates a predicted direction difference of in-screen prediction modes of a plurality of reference blocks used for in-screen prediction of an encoding object block. A priority mode determination section 603 determines a priority prediction mode of the encoding object block on the basis of the in-screen prediction modes of the plurality of reference blocks used for calculating the predicted direction difference and the predicted direction difference. An encoding tree selection section 605 selects one encoding tree, in which a code string having a code length shorter than that of other prediction modes is allocated to the priority prediction mode, depending on the calculated predicted direction difference, from a plurality of encoding trees prepared depending on the predicted direction difference, to encode the in-screen prediction mode of the encoding object block. A variable-length encoding section 606 encodes the in-screen prediction mode of the encoding object block according to the selected encoding tree. <P>COPYRIGHT: (C)2013,JPO&INPIT |
