PARAMETER UPDATE METHOD FOR ENTROPY CODING AND DECODING OF CONVERSION COEFFICIENT LEVEL, AND ENTROPY CODING DEVICE AND ENTROPY DECODING DEVICE OF CONVERSION COEFFICIENT LEVEL USING SAME

摘要

Abstract: A parameter update method that is used for entropy coding and decoding of a conversion is disclosed. A syntax element indicating a conversion coefficient level is binarized by using a parameter. The parameter is updated or maintained based on a result obtained by comparing the size of the previous conversion coefficient with a certain threshold obtained on the basis of the previous parameter used for the inverse-binarization of the previous conversion coefficient level syntax element. The certain threshold is set to have a value proportional to the previous parameter and if the previous parameter is updated, the updated parameter has a value that gradually increases in comparison to the previous parameter.