IMAGE SIGNAL RECORDING METHOD AND DEVICE, IMAGE SIGNAL REPRODUCING METHOD AND DEVICE AND IMAGE SIGNAL RECORDING MEDIUM

摘要

PURPOSE: To reproduce a moving image with high image quality while keeping compatibility with an optical disk on which an existing television signal is recorded. CONSTITUTION: A DCT coefficient generated by a DCT circuit 102 is given to a quantization circuit 103, in which the coefficient is quantized by a step size to a degree of meeting basic image quality. An output of the quantization circuit 103 is subject to variable length coding and recorded to a 1st layer of a multilayer optical disk. An output of the quantization circuit 103 is inversely quantized and a difference between the DCT coefficient before quantization and the DCT coefficient subject to inverse quantization is generated. The difference is quantized by a small step size by a quantization circuit 106, and subject to variable length coding and recorded to a 2nd layer of the optical disk. When the signals of the 1st layer only are reproduced, a reproduced image of the same degree as reproducing an existing optical disk is obtained and an image with high image quality is reproduced by reproducing the signals of the 1st and 2nd layers and inversely processing the reproduced output to an encoder.