| 摘要 |
PURPOSE:To mount a scramble expansion reproducing device for picture subjected to compression processing even on a decoder for pepole's livelihood in a simple constitution without raising the cost by merely rewriting a quantization parameter to perform scramble processing and eliminating a need of this processing means on the transmission equipment side. CONSTITUTION:Picture signal data are separated into picture data and compression parameters like a quantization matrix. Picture data are subjected to expansion processing by a variable length code decoding means 14, an inverse quantization means 15, and an inverse DCT 16 to decode a predictive difference picture. The predictive difference picture is added to the predictive picture of a movement predicting means 17 to reproduce the original picture by decoding. At this time, compression parameters other than the quantization matrix are sent to each processing means as they are and become processing parameters. The quantization matrix is sent to a scrambling means 13 and is rewritten in accordance with permission/inhibition of expansion reproducing discriminated by the parameter. The rewritten quantization matrix is subjected to inverse quantization processing by an inverse quantization means 15 and is subjected to scramble processing. |
