Method and arrangement for adjusting the discriminator of an image evaluating device

摘要

Image evaluating devices contain discriminators which are supplied with the video signal generated by a video scanning device. For it to be possible to recognise predetermined structures contained in the images to be evaluated, even under different illumination of the individual images, the discriminator is successively adjusted to different response ranges during one scanning period each. With each discriminator adjustment, a check is made as to whether the output signal of the discriminator meets criteria which correspond to the predetermined structures. The image is evaluated only when these criteria are met. The main application of the invention is television systems for automatic image evaluation. <IMAGE>