Process and device for the processing of video signals

Abstract
A process and a device for the processing of video signals for the increase of image contrast. According to this process and the device, the minimum and the maximum values a picture information are determined from a video signal of a predetermined time length in a suitably designed circuit part. Following this, an average value is formed between the determined minimum and maximum values in a circuit part, said average value applying a direct current level to the video signal of a predetermined time length. At approximately the same time as this, a differential value is determined between the determined minimum and maximum values in another circuit part, said differential value acting as a gain measuring parameter ultimately affecting the final gain of the video signal in an amplification circuit.