Abstract: A device is provided for correcting the contours in an image comprising in the green channel a contour extraction circuit followed by a circuit for processing these contours. It also comprises in the red channel a second contour extraction circuit followed by a second circuit for processing the contours. A validation circuit only validates the contour signal coming from the red channel when the red level is relatively high with respect to the green level. In this case, the red contour signal is superimposed on the contour from the green channel for correcting the contours of the three chrominance channels, by means of a mixing circuit.

Abstract: 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.