| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To reduce deterioration of picture quality when compression coding and expansion decoding of image data are repeated in a smaller circuit size. <P>SOLUTION: A residue calculation part 54 calculates residue of division by a reference value (8) based on an invariable (intra_dc_mult) used in decoding of image data, to an average value of a pixel value of image data for each DCT block. A tally part 55 tallies the number of DCT blocks which have been blocks of an intra macro block, based on the residue value for each DCT block. An I picture detection part 56 determines whether or not the picture of image data is coded as an I picture in previous coding based on the number of DCT blocks which have been blocks of intra macro block. This invention can be applied to a coder which carries out compression coding of an MPEG2 system. <P>COPYRIGHT: (C)2009,JPO&INPIT</p> |
