MOTION PICTURE CODER AND DECODER

摘要

PURPOSE:To obtain the device with less picture quality deterioration even when the device is simplified by subsampling an anticipation residual error as to a frame of acyclic prediction so as to reduce number of picture elements thereby executing in-frame coding and reducing the quantity of arithmetic operation. CONSTITUTION:In the case of a B frame, an input picture signal is led to a buffer 3 via a switch 2. The input picture signal is delayed and given to an anticipation subtractor 4 till two I frames required for 2-thetaway anticipation are inputted to the buffer 3. The subtractor 4 subtracts an inter-frame anticipation signal given from a anticipation device 12 from the picture signal and an anticipation residual signal is fed to a sub sampler 5. The anticipation residual signal in the sampler 5 is filtered corresponding to the sub sampling and both the signals in the vertical and horizontal directions are interleaved. The anticipation residual signal is inputted to a buffer 6 at a speed in matching with the output of the sampler 5 and outputted to an in-frame coder 8 in matching with the processing speed of the in-frame coder 8 from buffer 6.