PURPOSE: To prevent the deterioration of the picture quality at the time of decoding an image.

CONSTITUTION: In an encoding part ECC encoding is executed in 402 and 403 to each of an AC component and a DC component. In a decoding part 402, an error is detected and corrected in ECC decoding parts 103, 104, and in the case of an error which cannot be corrected completely, reproduction is executed by only the DC component in a DC converting part 108.