| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To establish a new technique for ensuring accuracy and accelerating processing speed in converting DCT (discrete cosine transformation) coefficient data formed in a JPEG system or the like into actual image data. <P>SOLUTION: Search is performed of the inputted DCT coefficient data in an order of zigzag scanning, and a ZRL code indicating continuous zero values is detected (S12). If a non-zero value existing near a higher-frequency than the ZRL code is not more than a threshold (S14), it is considered as an isolated non-zero value, and a group of components near a lower frequency side than the ZRL code is decided as a target range of transformation processing of IDCT (inverse discrete cosine transformation) (S16). A value correction is applied to at least one component in this target range, and compensation for disregarding the isolated non-zero value component is performed (S18). Then, the IDCT processing is performed for this target range (S20). <P>COPYRIGHT: (C)2006,JPO&NCIPI</p> |
