Patent ID: 9538205
Date: 2017-01-03
CPC Classifications: H04N

Claim:
1. An arithmetic decoding device for decoding coded data of a transform coefficient obtained by performing frequency transform on a target image for each unit domain, the device comprising: a sub-block coefficient presence/absence flag decoding unit configured to decode a sub-block coefficient presence/absence flag indicating whether or not one or more non-zero transform coefficient are included in each of a plurality of sub-blocks into which the unit domain is split; and a context index deriving unit configured to derive a context index corresponding to a transform coefficient presence/absence flag indicating whether or not the process target transform coefficient is 0, wherein the context index deriving unit is configured to derive the context index having one of three different values, in a case where the non-zero transform coefficient is not included in two or more adjacent sub-blocks which are adjacent to a process target sub-block.