| 摘要 |
<p>PURPOSE:To realize encoding with high efficiency by performing scan in an oblique direction when the DPCM(Differential Pulse Code Modulation) encoding of a sub-sampled sampled value is performed. 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 encoding processing is progressed sequentially in the diagonal direction. Therefore, it is possible to use a preceding sampled value in the oblique direction instead ef the preceding sampled value in a horizontal direction in which distance between the sampled values is separated after thinning as the predictor, and also, band limitation by pre-filtering is applied in the oblique direction to prevent the folding of subsampling, and inter-sampled value correlation is heightened. In such a way, the DPCM encoding with high predictive efficiency can be realized.</p> |
