| 摘要 |
<p>PROBLEM TO BE SOLVED: To avoid problems caused by overlapping by decreasing the capacity of a memory, realizing high compression efficiency, and dividing an image into tiles, without overlapping in the case of executing high efficiency compression through wavelet conversion. SOLUTION: This coder has a tile division section 1 that divides a received image 100 into plural tiles, a wavelet conversion section 2 that applies wavelet conversion to each tile picture division, a conversion coefficient scanning section 3 that scans a wavelet conversion coefficient, a quantization section 4 that quantizes the coefficient after scanning and an entropy coding section 5, that applies entropy coding the quantization coefficient to output a coded bit stream. The wavelet conversion section 2 has a function of applying symmetrical extension to pixels inside each tile and a convolution arithmetic operation to them within a range where filtering reaches in the outside of each tile.</p> |
