PICTURE CODING SYSTEM

摘要

PURPOSE:To provide a picture coding system attaining high compression coding of input pictures of plural gradations by the same system. CONSTITUTION:Input picture data are divided into plural rectangular block data by a block processing section 12 and they are inputted respectively to an orthogonal transformation section 14. Then each transformation variable is quantized adaptively by a quantization section 16 and the result is sent to a coding section 17. The coding section 17 decides an allocated code quantity for encoding in response to the gradation of input picture data and controls the sum of a code quantity allocated to a consecutive number of invalid coefficients obtained at quantization and a code quantity allocated to a valid coefficient group to be constant. The code quantity control and quantization control are executed based on control data publicated from a control section 15 in response to the gradation.