| 摘要 |
A video compression codec performs a comparison between a block of the present frame and the most recently encoded corresponding block from a previous frame for transmission of a 'skip' signal if the blocks are similar, wherein both present and previous blocks have been subjected to transform coding and the comparison is adapted to compare only a reduced set of N frequency coefficients such as those of lowest frequency or highest energy. Comparison between blocks of different frames can be carried out in transform space only if no motion estimation was involved in the transformation. The transform coding may be DCT, Fourier or Kurhunen-Loeve coding. Transformed blocks from the present frame to be transmitted are quantised and entropy coded. Entropy coding may be any lossless encoding such as run-length coding or Huffman coding. The invention has the advantage of not requiring any decoding of a transformed signal to provide a comparison. |
