| 摘要 |
<p>PURPOSE:To make it possible to detect a transmission error by using a picture signal error detecting system when executing sub-sampling of 2 cover 1 in the inter-frame encoding. CONSTITUTION:Output from an interpolation circuit 14 and that from an interpolation circuit 26 do not coincide with each other when there is a transmission error. Therefore, a parity signal transmitted from an arithmetic circuit 16 and a parity signal transmitted from an arithmetic circuit 28 are compared by a comparator 30 to detect the transmission error. However, when an even number of picture elements cause errors at a time on a bit plane, they cannot be detected by parity, but they remain as decoding prediction value, and next time when they are added to a prediction error signal to be input, the parity changes and the transmission error can be detected after the next frame. In case of field frame deletion, as the parity is figured out only for transmitted encoding picture elements, the transmission error can securely be detected by parity signal. Further, the same as the above can also apply to subsamples within a frame.</p> |
