ARITHMETIC DECODING DEVICE, IMAGE DECODING DEVICE, AND ARITHMETIC ENCODING DEVICE

摘要

In order to reduce the amount of processing related to encoding and decoding of conversion coefficients, for each sub-block resulting from the splitting of each unit area into two or more sub-blocks, a sub-block coefficient flag is decoded, the flag showing whether at least one non-zero conversion coefficient is included, and on the basis of the conversion-coefficient flag showing whether the conversion coefficient is zero, a context index for the sub-block is derived, the context index of the sub-block being derived in response to the sub-block coefficient flag of a sub-block adjacent to the sub-block.