| 摘要 |
<p>PURPOSE:To minimize picture deterioration by sending one picture element among picture elements in a block without modifying the original PCM signal, sending other picture elements while quantizing an error between a predicted value and the original picture element value and controlling the block position change for each frame or each field. CONSTITUTION:A picture element position detection circuit 1 detects the position of the picture element coded at present, and a control circuit 73 applies the control so as to vary the position of the block for each frame or each field and controls what kind of coding is to be applied depending on the position of the picture element. The coder is provided with selectors 4-6 selecting the coded signal by the control circuit 73, plural prediction devices 9-11, a quantizer 2, a represent value setting circuit 3, a subtractor 7 and an adder 8. One picture element among picture elements in a block is sent without modifying the PCM signal and other picture elements are sent while quantizing an error between a predicted value in use with a local decoding signal of the picture element coded already in one block or the PCM signal and the original picture element value. Thus, the picture signal whose deterioration is not distinct is decoded.</p> |
