AC COEFFICIENT PREDICTIVE CODING METHOD IN OBJECT SHAPE INFORMATION CODING, OF WHICH PROBLEM OF LOWERED PREDICTIVE CODING GAIN IS SOLVED

摘要

PURPOSE: An AC(Alternate Current) coefficient predictive coding method in object shape information coding is provided to predictive-code a random AC coefficient of a current block using another AC coefficient, thereby increasing coding efficiency and reducing the number of bits upon variable coding. CONSTITUTION: An AC coefficient of a block to be coded is calculated. The calculated AC coefficient and a preset predictive value of an adjacent block are selected to perform predictive coding of the AC coefficient of the block to be coded. If a predictive value of the AC coefficient of the block to be coded is 0(zero), the AC coefficient of the block to be coded is decided as a coded value, and then the coding is performed.