Patent ID: 8559736

Claim:
An image decoding apparatus which decodes a coded stream, comprising: a decoding unit configured to decode, from the coded stream, identification information identifying each of a plurality of orthogonal transform bases for use in inverse orthogonal transform of the coded stream; an accumulation unit configured to store the plurality of orthogonal transform bases for use in the inverse orthogonal transform of the coded stream; a storage unit configured to store at least one orthogonal transform basis which is required for current inverse orthogonal transform of a current block, out of the orthogonal transform bases stored in said accumulation unit; an inverse orthogonal transform unit configured to perform the current inverse orthogonal transform using the at least one orthogonal transform basis stored in said storage unit and identified based on the identification information; and a transfer control unit configured to transfer, from said accumulation unit to said storage unit, the at least one orthogonal transform basis identified based on the identification information.