MOTION COMPENSATION

(n.) In the MPEG and H.261 encoding standards, the approach to interframe compression that is based on the assumption that a macroblock in the frame being encoded can be represented mostly as a translation of a macroblock in a previous frame. That is, for the current macroblock, the encoder specifies one or two reference macroblocks (one from a previous frame and possibly a second from an ensuing frame) and one or two motion vectors that indicate how far and in which direction the macroblock has moved. See also data compression .