PICTURE ENCODER AND DECODER

摘要

PURPOSE:To obtain a naturally reproduced picture without the distortion of a grid- shaped block by extracting the area of a mobile object without the division of the grid-shaped block and executing movement-compensation to the area. CONSTITUTION:An extractor 101 applies an threshold-processing to the difference of a present frame picture and a frame buffer output picture so as to extract the changing area and a movement detector 102 obtains a mapping parameter to the respective changing areas from the lumninance gradation and frame difference of the present frame picture and the frame buffer output picture. A movement compensator 103 executes movement-compensation to the buffer output picture based on the mapping parameter and generates a predictive picture to the present frame picture. A difference detector 104 extracts the prediction unable area, a divider 105 divedes an area and an orthogonal transformation device 106 obtains a transformation factor to the respective divided areas so as to make orthogonal transformation in accordance with an area shape. An inverse transformation device 107 obtains a transformation base from the divided area shape and decodes a signal value inside the area by the transformation factor so as to synthesize (108) it with the predictive picture and obtain the reproduced picture.