| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To accelerate processing of converting data from a frequency region into a spatial region in decoding image data. <P>SOLUTION: In performing inverse DCT, an arithmetic processor 1 determines whether or not one-dimensional inverse DCT processing concerning rows and columns of a block can be omitted, depending on whether or not an inverse DCT coefficient to be used is "0" for the rows and columns of the block. Only when determining that the omission is not permitted, the arithmetic processor 1 executes the inverse DCT processing. Also, in processing the block, the arithmetic processor 1 performs one dimensional inverse DCT processing for each row, and then performs one dimensional inverse DCT processing for each column. Accordingly, since the inverse DCT coefficient is fixed in processing each row and each column and the inverse DCT processing can be omitted for rows and columns needing no processing, it is possible to accelerate the inverse DCT processing. <P>COPYRIGHT: (C)2005,JPO&NCIPI</p> |
