Verfahren zur Detektion einer Szenenänderung

摘要

A scene change detector operates on an image signal which has been converted to a spatial-frequency distribution by an orthogonal transformation circuit such as a discrete cosine transformation circuit (18). A DC coefficient extracting section (27) extracts the DC component of the spatial-frequency distribution for each of a plurality of blocks in the image. These values are stored for successive frames in two stores (29,30) and the differences between them calculated by a circuit (31). The absolute values of the differences are taken (32) and a discriminating circuit (33) determines whether the differences exceed a threshold. A scene change is indicated if the threshold is exceeded for more than a predetermined number of blocks in the frame.