PURPOSE: To enable efficient encoding while suppressing practical image degradation and decreasing the amount of codes by preventing the degradation from being conspicuous for human sight even when filter processing is executed.
CONSTITUTION: The edge part of an input image signal is detected by an edge detecting means 14 and corresponding to the detected result, the operation of a filter circuit 10 is controlled. On the other hand, a coefficient K of the circuit 10 is decided corresponding to a local change degree (e) of the signal. Namely, encoding processing is performed for the unit of a block, the local change degree is detected within the same range as this block, and the coefficient of the circuit 10 is also set and changed within the same range as this block. Corresponding to a target value C of the code amount due to encoding, the coefficient of the circuit 10 is revised, and the coefficient of the circuit 10 is set corresponding to encoding processing. Afterwards, the edge part of the input image signal is detected by using the means 14, the local change degree (e) of the input image signal is detected by a local change degree detecting means 18, and the circuit 10 is controlled corresponding to these two detected results at least.
URANO TEN
KODAMA HIDEO
KOBAYASHI TOMOKO
SUGIMOTO ETSUKO
