SCENE CHANGE DETECTOR FOR DETECTING A SCENE CHANGE OF A MOVING PICTURE

A scene change detector for detecting a scene change of a moving picture reproduced by a series of frames of pictures, consists of a frame memory for storing a frame of picture from among the frames of pictures one after another, a switch for selectively passing a current frame stored in the frame memory after selectively passing a preceding frame stored in the frame memory, an activity calculating circuit for calculating a second activity of the current frame after calculating a first activity of the preceding frame, a first activity memory for storing the second activity after storing the first activity, a delay circuit for delaying the first second activity until the current frame is stored in the frame memory, a second activity memory for storing the first activity delayed in synchronism with the storage of the second activity in the first activity memory, and a scene change judging circuit for judging a scene change of the moving picture by comparing the both activities. The activity is defined as complexity of a frame of picture, and the scene change occurs in the current frame when the first activity greatly differs from the second activity.