Method of reducing the visibility of the noise in a sequence of video images and device for implementing this method

Abstract

Abstract The invention relates to a method and a device for reducing the visibility of the noise in a sequence of video images by filtering the luminance value of the fixed points and of the points whose motion is due to the noise by an inter-image recursive filtering and by filtering the points with true motion by a median filtering consisting in replacing a luminance value by the median value of the luminance values situated within a window centred on the relevant point, these latter values being ordered. The device includes: a motion detector 2; a median filter 4; an inter-image recursive filter 5; an image memory 3; a multiplexer with two inputs and one output 6; and a bidirectional recursive filter 7. The multiplexer 6 transmits: either a filtered value provided by the output of the median filter 4, when the point has a true motion; or a filtered value provided by the inter-image recursive output 5 when the point is fixed or has a motion due to noise. The bidirectional recursive filter 7 filters the values provided by the output of the multiplexer 6 whatever the state of the point processed, so as to smooth out the demarcations between zones in which the filtering differs. Application to the reduction of noise in television images.

Inventors

• 👤 Christian Richard
• 👤 Philippe Sadet
• 👤 Philippe Salmon

Bibliographic Details