MOVEMENT COMPENSATING INTER-FRAME CODING DEVICE

摘要

PURPOSE:To obtain optimum quantizing width by providing the coding device with a quantizing width control circuit for controlling the quantizing width based upon a forecasting error obtained from a movement compensating part and an transmitted coding variable in a line buffer. CONSTITUTION:A dynamic vector detecting circuit 111 detects and outputs a dynamic vector from a reproduced image outputted from a frame memory 113 and an input image inputted from a terminal 101. The detected dynamic vector is inputted to a coding circuit 105 and the frame memory 113 and used for coding and the output of a forecasting value. At the time of detecting the dynamic vector, the circuit 111 outputs a calculated evaluation value to the quantizing width control circuit 110. The circuit 110 determines the optimum quantizing width from the untransmitted coding variable, i.e., a residual buffer value and the calculated evaluation value, of a line buffer 106 and outputs the determined value to a quantizing circuit 104. Thus, the quantizing widht for generating a code variable appropriate for a line rate can be selected and the coding variable appropriate for the line rate can be generated.