Abstract: A filter performs a reduction of pulsed noise in video images in accordance with fuzzy logic. An interface circuit of the filter receives consecutive digital signals in time corresponding to the video images and generates an image window having a digital signal to be processed at the center. The filter also has a comparator block, a plurality of digital subtractors, and a memory circuit connected in cascade to the comparator block. The filter also has a filtering circuit that organizes values of digital signals of the video image, and an arithmetic block that performs a switch between the digital signal to be processed and the output of the filtering circuit on the basis of the values taken by the parameter.

Abstract: A phase-lock loop circuit with fuzzy control, includes a phase comparator whose output is connected to a low-pass filter that drives a voltage-controlled oscillator. The phase comparator generates a signal that represents the phase difference between an input signal and a signal generated by the oscillator. The oscillator of the present invention is furthermore driven by a control signal generated by fuzzy control. The input of the fuzzy control is the signal that represents the phase difference.

Abstract: A fuzzy device for image noise reduction, includes an interface adapted to retrieve the gray level of a pixel to be processed of an image and of neighbouring pixels; a difference circuit connected to the interface and adapted to generate a difference of the gray levels between said neighbouring pixels and said pixels to be processed; a fuzzy flat area smoothing circuit connected to the difference circuit and adapted to perform a low-pass smoothing of an almost homogeneous region defined by said pixel and by said neighbouring pixels; an edge preserving smoothing circuit connected to the difference circuit and adapted to perform low-pass filtering on a high-frequency information region defined by the pixel and by the neighbouring pixels; a region voter circuit connected to the interface and adapted to give a measure for considering whether the region defined by the pixel and the neighbouring pixels is almost homogeneous; and a soft switching circuit connected to the outputs of the smoothing circuit and adapted