A method and apparatus are provided for estimating motion and sequence of video images. A plurality of fields of a sequence of video images are stored, then, for each of plurality of blocks of pixels in each field, a test is performed on a set of candidate motion vectors to determine which motion vector gives the best fit in determining the motion between adjacent fields for that block. The testing step includes determining the amount of motion blur present in the image and modifying the testing of candidate motion vectors in dependence on this motion blur.