Apparatus for motion vector estimation in a television image using a digitized signal representing the image, comprises a vector filter and a vector calculator for determining motion in the image at points spaced a predetermined number of pixels horizontally and a predetermined number of pixels vertically by a block matching technique, thereby to derive motion vectors, and a sub-pixel motion estimator for refining the selection of the motion vectors by determining a sub-pixel offset representing motion between fields of the image not equal to an integral multiple of the spacing between pixels.