Patent ID: 6931065

Claim:
An apparatus for detecting a motion of an image frame in a digital video recording system having a Moving Picture Expert Group (MPEG) video compression apparatus, comprising: a motion estimation unit for receiving a reference image frame and a current image frame, and estimating a motion vector (MV=(mx,my)) with respect to a motion of an object in the motion detection area of the image frames based on the received reference image frame and the current image frame; a motion compensation unit for calculating a motion compensated prediction error E MV (i) based on the estimated motion vector (MV=(mx,my)); a frame difference calculation unit for calculating a frame difference (E 0 (i)) which is a difference between the reference image frame and the current image frame, the frame difference being an error without motion compensation, with respect to all the blocks included in the motion detection area of the reference image frame, which is not motion-compensated, and the current image frame; a motion block accumulation unit for accumulating the number (B motion ) of motion blocks in the current image frame by determining whether a block has a motion or not based on the motion compensated prediction error E MV (i) and the frame difference E 0 (i); and a motion frame determination unit for determining whether the current image frame has a motion or not, based on the accumulated number B motion of motion blocks.