Patent ID: 7864838

Claim:
A picture decoding apparatus which decodes, on a block-by-block basis, a picture that is coded and included in a coded signal, said picture decoding apparatus comprising: a variable length decoding unit configured to decode a frame weighting factor that is coded and included in the coded signal, and to generate a field weighting factor from the decoded frame weighting factor, in the case where the picture has a frame structure and is coded such that switching between frame decoding and field decoding of a block included in the picture is adaptively performed; a motion compensation unit configured to generate a predictive image by scaling pixel values of a reference frame to which the block refers using the decoded frame weighting factor, in the case where the block included in the picture is frame coded, and to generate a predictive image by scaling pixel values of a reference field to which the block refers using the generated field weighting factor, in the case where the block is field coded; and an addition unit configured to reconstruct the picture using the generated predictive image.