Patent ID: 8068542

Claim:
A motion picture decoding method comprising: decoding, by a decoder, a motion picture signal composed of a top field and a bottom field and encoded with inter-field motion compensating prediction, each field formed in a 4:2:0 picture format, said decoding comprising: generating a chrominance motion vector from a luminance motion vector of the encoded motion picture signal according to a respective calculation method adaptively selected from a plurality of different calculation methods depending on parities of a coding field, which is one of the top field and the bottom field, and a reference field, which is one of the top field and the bottom field, of the encoded motion picture signal, wherein a first calculation method is employed for generating the chrominance motion vector from the luminance motion vector when both the coding and reference fields are the top fields or the bottom fields, a second calculation method is employed for generating the chrominance motion vector from the luminance motion vector when the reference field is the top field and the coding field is the bottom field and a third calculation method is employed for generating the chrominance motion vector from the luminance motion vector when the reference field is the bottom field and the coding field is the top field.