| 摘要 |
<p>PURPOSE:To reduce deterioration in picture quality due to the error of a transmit signal and to reproduce a proper image by detecting the code error of an image signal after predictive coding, and restoring a signal which has a code error by using a signal which has no code error when the error is caused by transmission. CONSTITUTION:A DPCM(differential PCM) encoding part performs DPCM encoding by a DPCM encoding circuit 2 and an error correction bit adding circuit 4 and a transmit signal to which a bit for error correction is added for every horizontal scanning line is transmitted through a transmission line. A DPCM decoding part detects and corrects a code error in the input transmit signal by an error correcting circuit 6. When there is no uncorrectable error, a switch 10 has contacts C and A connected and the signal is decoded by a DPCM decoding circuit 12 and outputted as a decoded image signal. If an uncorrectable error is detected, the switch 10 has contacts C and B connected with a switch control signal from a control line l, and a transmit signal which is obtained from a 263H delay circuit 8 and one field (263H) before is led out from the movable contact C and sent out of the DPCM decoding circuit 12 as a restored image signal.</p> |
