PICTURE CODER

• Main Author: KATADA HIROYUKI
• Format: Patent
• Language: English
• Published: 21.02.1995
• Edition: 6
• Subjects: CALCULATING; COMPUTING; COUNTING; ELECTRIC COMMUNICATION TECHNIQUE; ELECTRICITY; IMAGE DATA PROCESSING OR GENERATION, IN GENERAL; PHYSICS; PICTORIAL COMMUNICATION, e.g. TELEVISION

PURPOSE:To realize coding with an excellent compression efficiency by devising the coder such that distortion is not protruded up to the outside of a block even when the distortion is produced in the block. CONSTITUTION:A sub band divider 11 applies sub band division to an original picture into a low frequency picture and plural high frequency pictures, an orthogonal transformation device 12 divides a low frequency picture into blocks of a 1st size to subject to an orthogonal transformation. The block dividor 13 divides a high frequency picture into blocks of a 1st size. The block of the 1st size subject to orthogonal transformation and a block of the 1st size of the high frequency picture are synthesized to form a block of a 2nd size to make hybrid transformation. A frame memory 21 rearranges hybrid transformation coefficient to generate a low frequency picture and some high frequency picture, an inverse orthogonal transformation device 22 divides the low frequency picture into blocks of the 1st size, applies inverse orthogonal transformation to the blocks, and a sub band synthesizer 23 synthesizes the entire picture through sub bands to apply inverse hybrid transformation.