Patent ID: 8665957

Claim:
A motion picture decoding method for making an inter-field motion compensation prediction and executing a decoding process on a motion picture signal by using a motion vector, wherein each frame is composed of two fields being a top field and a bottom field, respectively, one of a decoding field and a reference field is the top field, and the other of the decoding field and the reference field is the bottom field, a number of pixels of a chrominance vertical component is different than a number of pixels of a luminance vertical component, a horizontal component and a vertical component of a luminance motion vector indicating vertical displacement of one luminance pixel of a field image by a value of “1” of a vector component of the luminance motion vector as units are MVx and MVy, respectively, and a horizontal component and a vertical component of a chrominance motion vector indicating vertical displacement of one chrominance pixel of a field image by a value of “1” of a vector component of the chrominance motion vector as units are MVCx and MVCy, respectively, the method comprising: determining when the combination of the reference field and the decoding field are the top field and the bottom field, respectively; and when said determining determines that the combination of the reference field and the decoding field are the top field and the bottom field, respectively, generating the chrominance motion vector defined by the equation: (MVCx, MVCy)=(MVx/2, MVy/2+0.25), so that the generated chrominance motion vector and the luminance motion vector are thereby parallel.