| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an image decoding method having improved coding efficiency. <P>SOLUTION: The image decoding method includes: a deriving step of deriving the predictive value of the number of non-zero coefficients included in a block to be decoded based on the number of the non-zero coefficients included in decoded blocks positioned in the periphery of the block to be decoded, wherein each non-zero coefficient is a coefficient having a value other than "0"; a selecting step of selecting variable-length tables based on the predictive value derived by the deriving step; and a variable-length decoding step of performing variable-length decoding on code sequences in which the number of non-zero coefficients included in the block to be decoded is coded, by using the variable-length code tables selected by the selecting step. In the deriving step, the predictive value is derived based on a median in the numbers of non-zero coefficients included in each of the decoded blocks positioned in the periphery of the block to be decoded. <P>COPYRIGHT: (C)2011,JPO&INPIT |
