A method and apparatus for encoding video includes selecting a prediction
motion vector for a current block of a current image frame from
respective motion vectors of two or more neighbor blocks of the current
block. Then the current block and a neighbor block corresponding to said
prediction motion vector are checked to determine whether they are motion
correlated. Checking motion correlation includes determining that the
difference between the best correlation from the correlation of the
current block with one or more neighbor blocks and the correlation of the
neighbor block with a block in the previous image frame at a location
defined by the prediction motion vector fulfils a predetermined
criterion.