ARITHMETIC DECODING METHOD AND ARITHMETIC ENCODING METHOD

摘要

PROBLEM TO BE SOLVED: To provide an arithmetic decoding method and an arithmetic encoding method that can properly initialize a context variable and enhance the encoding efficiency.SOLUTION: An arithmetic decoding method for initializing a context variable for specifying an occurrence probability of a value which an individual array element contained in a binary array corresponding to the value of a predetermined variable can take, and arithmetically decoding the binary array by using the context variable, extracts a first parameter representing the characteristic of an input signal from encoded data, determines a second parameter for specifying one initialization method from plural candidates of the initialization method of the context variable on the basis of the first parameter, and initializes the context variable by using the one initialization method specified by the second parameter.SELECTED DRAWING: Figure 8