IMAGE COMPRESSION CODER AND COMPRESSED IMAGE DECODER

• Main Authors: MITA HIDEAKI, SAKAUCHI TATSUJI, SAITO HIROSHI
• Format: Patent
• Language: English
• Published: 20.02.1996
• Edition: 6
• Subjects: BASIC ELECTRONIC CIRCUITRY; CODE CONVERSION IN GENERAL; CODING; DECODING; ELECTRIC COMMUNICATION TECHNIQUE; ELECTRICITY; PICTORIAL COMMUNICATION, e.g. TELEVISION

PURPOSE:To enhance the coding efficiency and to correct an error by separating a linear orthogonal transformation coefficient with respect to picture element blocks of a specific number into a high order block and two low order sub blocks and deciding a two-dimensional orthogonal transformation coefficient for each block. CONSTITUTION:Picture element blocks for (n-m)X2w picture elements are subject to (n+m) orthogonal transformation by a linear orthogonal transformation means 11, the transformation coefficients are separated into an nX2w low order block and mX2w high order block by a coefficient separate means 12 and the low-order block is separated into nXw even and odd number coefficient sub blocks by a coefficient interleave means 13. Then the high order block and the sub blocks are converted by a 2w coefficient linear orthogonal transformation means 14 and w coefficient linear orthogonal transformation means 15, 16 to decide a two-dimensional high order transformation coefficient and two-dimensional low order transformation coefficients Le, Lo. By this constitution, the coding efficiency is enhanced for the high order coefficients and the coefficients Lo, Le of the low order are sent independently and an image is corrected through interpolation in the case of disable error correction.