| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide an image decoder that can apply resolution conversion to a block including the border of contents. SOLUTION: Two-dimensional orthogonal transform processing is applied to signals of all pixels for an internal block of image signals and pixels signals only included in the contents for an edge block according to an alpha map signal denoting a position and a shape of the contents, transform coefficients are coded and a map signal is coded, the decoder selects the orthogonal transform coefficient required for reproducing an image with a desired resolution from the decoded orthogonal transform coefficient on the basis of the decoded and resolution converted map signal, all coefficients of the internal block, and coefficients included inside the contents for the edge block are respectively subjected to two-dimensional inverse orthogonal transform and a reproduced image signal with a converted resolution is obtained.</p> |
