CODING METHOD, CODING APPARATUS, DECODING METHOD, DECODING APPARATUS AND PROGRAMS THEREOF

摘要

AN ENCODING METHOD FOR ENCODING NON-O COEFFICIENT QUANTITY DATA OF TRANSFORMATION COEFFICIENTS OBTAINED BY PERFORMING ORTHOGONAL TRANSFORMATION ON IMAGE BLOCK DATA HAVING A SECOND BLOCK SIZE, WHICH IS A MULTIPLE OF A FIRST BLOCK SIZE, BASED ON CORRESPONDENCE DATA IN ACCORDANCE WITH SAID FIRST BLOCK SIZE; WHEREIN A SUB BLOCK GENERATION CIRCUIT DIVIDES COEFFICIENTS OF ORTHOGONAL TRANSFORMATION BY 8X8 TO SUB BLOCK DATA, AND A TWO-DIMENSIONAL REVERSIBLE CODING CIRCUIT 54 SELECTS TRANSFORMATION TABLE DATA FOR ASSIGNING AN ENCODING CODE HAVING A SHORT BIT LENGTH TO NON-O COEFFICIENT QUANTITY DATA INDICATING "0" IN NON-O COEFFICIENT QUANTITY DATA OF A SUB BLOCK BEING AWAY FROM DIRECT CURRENT COMPONENTS, AND PERFORMS ENCODING.