PICTURE DATA CODING SYSTEM

摘要

PURPOSE:To process the coding of a gradation picture data at a high speed by extracting only a code word satisfying a conditional equation in which each picture element on a code word is resident within a prescribed range and applying distortion calculation based on the code word and a block picture. CONSTITUTION:Picture numbers among picture elements 11 of a block picture 13 covering maximum and minimum picture elements are retrieved respectively and only a code word 23 satisfying a conditional equation where each picture element on the code word 23 having the same picture element numbers as those picture element numbers is resident within a prescribed range respectively with respect to a threshold value based on the picture element value on the block picture 13 is extracted and the distortion calculation is implemented based on the code word 23 and the block picture 13. Thus, an index of a code word giving a minimum distortion is outputted and a contrast picture data is coded at a high speed.