| 摘要 |
<p>PURPOSE:To realize DPCM(Differential Pulse Code Modulation) encoding with high predictive efficiency by performing the DPCM encoding byusing a sampled value in a diagonal direction with high correlation be tween the sampled values, and performing the encoding sequentially as converting the direction of encoding processing cyclically in a reverse diagonal direction. CONSTITUTION:A pre-filter circuit 102, a subsampling circuit 103, a scan conversion circuit 104, and a DPCM encoder circuit 105 are provided, and the calculation of a predictor is performed by using a neighboring sampled value including the sampled value in a diagonal direction out of the sampled values after thinning, and the progressive direction of the encoding processing is converted cyclically in a reverse diagonal direction. Therefore, the DPCM encoding with high predictive efficiency can be realized, and also, a code can be outputted in sequence arranging in arranging shape, and the encoding advantageous for the processing at a rear stage can be realized. In addition to that, band limitation in the diagonal direction of subsampling is performed with pre-filtering to prevent a folding noise due to a high frequency generally, and the correlation between the sampled values can be heightened. Thereby, an encoder advantageous for predictive encoding can be obtained.</p> |
