Abstract: A video for one frame is captured and two adjacent frames are compared, the result of which is detected as a change degree of the video. Then, based on the magnitude of the change degree, it is determined whether a scene change (SC) exists. If an SC exists, it is examined whether its change degree alters rapidly or gradually, to determine the SC as a momentum or gradual SC. For the momentum SC, its determination point is detected as the momentum SC. For the gradual SC, its determination points is detected as the start of the gradual SC, thereafter, its end is detected. According, for one gradual SC, plural SC's are not detected and a midway illegible video is not indicated as an index picture.

Abstract: In a display device for displaying one or more moving pictures and a graphic picture on the same display unit, a plurality of moving picture units are provided; each a moving picture unit consists of an input unit, a frame picture and computer control unit, and a mixer for mixing the signals from the respective moving picture units and a graphic picture unit. Therefore, when the instruction producing unit provides an instruction, the mixer mixes the graphic picture and one or more moving pictures such that a graphic picture and a plurality of moving pictures can be displayed on the same display unit simultaneously.