CORRECTION DEVICE FOR A TELEVISION VIDEO SIGNAL WITH DYNAMIC ATTENUATION OF THE NOISE LEVEL, AND TELEVISION PICTURE GENERATOR COMPRISING SUCH A DEVICE

摘要

A correcting device for dynamically reducing the noise pollution level with respect to a videofrequency signal mainly comprises an analog multiplier in which two previously generated signal components are multiplied by each other. One signal designated as the filtered signal is the result of a passage of the initial signal through a low-pass filter. The other signal or so-called contour signal is the difference between the initial signal and the filtered signal. The contour signal noise is cancelled at the time of the zero-crossings of the filtered signal and variably attenuated according to the level of the filtered signal in the case of the other levels of the signal. Addition of the filtered signal and of the contour signal processed and suitably adjusted for amplitude reconstitutes a corrected videofrequency signal.