IMAGE CODER AND IMAGE CODING METHOD, AND IMAGE DECODER AND IMAGE DECODING METHOD, AND QUANTIZATION CONTROL METHOD AND INVERSE QUANTIZATION CONTROL METHOD, AND DATA RECORDING MEDIUM

摘要

An image coder (1) is equipped with a coding controller (112a) which produces a transmittance coding parameter (121) for controlling the coding processing of a transmittance signal, based on a picture element value coding parameter (104) for controlling the coding processing of a picture element value signal and coding-processes the transmittance signal (102) based on a transmittance coding parameter (121), as shown in the Figure. In such constitution of image coder (1), it becomes possible to control the quality of a picture obtained from the transmittance signal of each image, according to the quality of a picture obtained from the picture element value signal of each image in a composite image, whereby redundant information in a transmittance coded signal (106) obtained by coding that transmittance signal can be curtailed, without damaging the picture quality of individual images, consequently the image signal can be recorded and transmitted without lowering the picture quality with fewer bits.