PICTURE ENCODER, ITS METHOD, PICTURE DECODER, ITS METHOD, PICTURE TRANSMITTER, PICTURE RECEIVER AND RECORDING MEDIUM

摘要

PROBLEM TO BE SOLVED: To obtain a picture of high quality by multiplexing a part of encoding bit stream of a complex picture to a frame of a small bit quantity at another time. SOLUTION: An encoding difficulty measuring device 701 evaluates the complexity of the picture and calculates an assigning bit quantity bitx necessary for encoding a moving picture corresponding to GOP of MPEG, e.g. with a fixed picture quality at a level more than a prescribed one. Then a controller 703 sorts the assigning bit quantity bitx to a basic picture quality signal assigning bit quantity bit 1 and an improved picture quality signal assigning bit quantity bit 2 based on a total transmittable bit quantity to respectively send to a basic picture quality signal encoding circuit 601 and an improved picture quality signal encoding circuit 602. The circuit 602 encodes and outputs a bit stream bs2 so as to obtain a desired picture quality corresponding to the complexity of the picture, multiplexes and transfers it to another frame small in the basic picture quality signal bit stream bs1.