VIDEO EMPHASIZER DEVICE

PROBLEM TO BE SOLVED: To emphasize the edge of a picture by inputting an inputted video signal to an edge detector, detecting the edge within the video and making the detecting result the control signal of a gradation correcting processing to improve the contrast of the whole picture. SOLUTION: The inputted video signal is inputted to the edge detector 1 to detect the edge within the video and this edge detecting result is outputted to the gradation correcting device 2 as the control signal of the gradation correcting processing. The device 2 executes the gradation correction of a luminance signal and a chrominance signal being the video signal by relating to the edge information by using the edge detection signal obtained by the device 1. Thereby the contrast of the whole picture is improved and the edge of the picture is emphasized. In this case, both of the luminance and chrominance signals are used as the inputted signal to the device 1 but it is possible to use only one of the signals for detecting the edge. In addition the effect of a picture filter is obtained more easily by executing the gradation correcting processing as preprocessing before a general picture filter processing.