| 摘要 |
PROBLEM TO BE SOLVED: To improve the image quality of expanded image by preserving the pixel values of input image concerning the expanded image, which is prepared by using converting processing such as frequency conversion, and to prevent the generation of new degradation even after the repetition of compression and extension by applying this image quality for compressing images. SOLUTION: A converting part 20 converts input image data 100 while using conversion base data 120 applied from a base calculation part 30 and sends out these data to a coefficient interpolation part 40 as conversion coefficient data 110. The coefficient interpolation part 40 prepares expanded conversion coefficient data 130 by interpolating the conversion coefficient data 110 based on the scale of expansion and sends them out to an inverse converting part 50. The inverse converting part 50 prepares expanded image data 140 by inversely converting the expanded conversion coefficient data 130. Concerning the base of converting processing calculated by the base calculation part 30, converting processing is made correspondent to inverse converting processing so that the base can become an inverse matrix for a partial matrix corresponding to the expansion scale among the converting matrixes of inverse converting processing. |
