| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a means for speedily executing image processing in a compressed domain by directly handling DCT domain representation data. <P>SOLUTION: A system is configured for performing downsampling and inverse motion compensation on a compressed domain representation form. For downsampling, a compressed stream is directly processed in a compressed DCT domain without explicit decompression and spatial domain downsampling, so that a desired scaled-down image is output. For inverse motion compensation, motion compensated compressed video is converted into a sequence of DCT domain blocks corresponding to the spatial domain blocks in the current picture alone. Namely, each picture is represented as a sequence of DCT blocks independent of data of other frames. By performing the inverse motion compensation directly in the compressed domain, necessity to inversely calculate the motion compensation from compressed data is eliminated. <P>COPYRIGHT: (C)2008,JPO&INPIT |
