Patent Document ID: 6141381
Application ID: 09065365
Patent Flag: 1

Claim One:
1. A motion compensation encoding apparatus for converting a stream of pictures expressed by an input video signal into a code stream including encoded motion vectors corresponding to respective blocks of picture elements of said pictures, the apparatus comprising: motion estimation means (15) for deriving, for each of said blocks, a corresponding estimated motion vector, first error amount detection means (16) for deriving, for said each block, a block prediction error amount which results from using said corresponding estimated motion vector to predict respective values of the picture elements of said block by motion compensation prediction, motion vector prediction means (20) for utilizing at least one previously encoded motion vector to derive a predicted motion vector for said each block, second error amount detection means (19) for deriving a second block prediction error amount which results from using said predicted motion vector to predict said values of the picture elements of said block by motion compensation prediction, comparator means (17) for comparing said first block prediction error amount and second block prediction error amount, to produce a comparison output indicative of a smaller one of said first block prediction error amount and second block prediction error amount, and selector means (14) responsive to said comparison output for selecting one of said estimated motion vector and predicted motion vector to be applied in motion compensation encoding of said each block and to be encoded as part of said encoded motion vectors.