Method and device for de-noising a digital video signal, and corresponding computer program product
AssigneeSTMicrolectronics S.A.
InventorDaniele Alfonso
Life of this patent
Estimating the term…
Abstract
A method may denoise a digital video signal produced by a photoelectric sensor as a matrix of pixel signals affected by both thermal noise and impulsive noise. The method may include estimating the noise level associated to the pixel signals, and filtering the pixel signals with an attenuation factor that is a function of the estimated noise level.
Claims25
A method of reducing noise in a digital video signal generated by a sensor comprising a matrix of pixels generating a plurality of pixel signals, the method comprising:
- estimating a respective thermal noise level for each pixel signal in the plurality thereof based upon a first distribution;
- estimating a respective shot noise level for each pixel signal in the plurality thereof based upon a second Poisson distribution;
- and
- filtering each pixel signal with a respective attenuation factor based upon the respective estimated thermal noise level and respective estimated shot noise level.
A device for reducing noise in a digital video signal from a sensor comprising a matrix of pixels generating a plurality of pixel signals, the device comprising:
- an encoder;
- and
- an processor to be coupled to said encoder and configured to
- estimate a respective thermal noise level for each pixel signal in the plurality thereof based upon a first distribution;
- estimate a respective shot noise level for each pixel signal in the plurality thereof based upon a second Poisson distribution;
- and
- filter each pixel signal with a respective attenuation factor based upon the respective estimated thermal noise level and respective estimated shot noise level.
A computer-implemented method for reducing noise in a digital video signal from a sensor comprising a matrix of pixels generating a plurality of pixel signals, the method comprising:
- estimating a respective thermal noise level for each pixel signal in the plurality thereof based upon a first distribution;
- estimating a respective shot noise level for each pixel signal in the plurality thereof based upon a second Poisson distribution;
- and
- filtering each pixel signal with a respective attenuation factor based upon the respective estimated thermal noise level and respective estimated shot noise level.
A method of reducing noise in a digital video signal generated by a sensor comprising a matrix of pixels generating a plurality of pixel signals, the method comprising:
- estimating a respective thermal noise level for each pixel signal in the plurality thereof based upon a first distribution;
- estimating a respective shot noise level for each pixel signal in the plurality thereof based upon a second Poisson distribution;
- estimating an average noise level associated with a group of pixel signals from the plurality thereof, the group of pixel signals defining at least a part of an image in the digital video signal;
- determining an average level of the group of pixel signals;
- determining a respective estimated noise level for the group of pixel signals by weighting the average noise level as a function of a ratio of the pixel signal and the average level of the group of pixel signals;
- estimating a respective noise level for each pixel signal by weighting the average noise level with a square root value of the ratio;
- and
- filtering each pixel signal with a respective attenuation factor based upon the respective estimated noise level.
A device for reducing noise in a digital video signal from a sensor comprising a matrix of pixels generating a plurality of pixel signals, the device comprising:
- an encoder;
- and
- an processor to be coupled to said encoder and configured to
- estimate a respective thermal noise level for each pixel signal in the plurality thereof based upon a first distribution,
- estimate a respective shot noise level for each pixel signal in the plurality thereof based upon a second Poisson distribution,
- estimate an average noise level associated with a group of pixel signals from the plurality thereof, the group of pixel signals defining at least a part of an image in the digital video signal,
- determine an average level of the group of pixel signals,
- determine a respective estimated noise level for the group of pixel signals by weighting the average noise level as a function of a ratio of the pixel signal and the average level of the group of pixel signals,
- estimate a respective noise level for each pixel signal by weighting the average noise level with a square root value of the ratio, and
- filter each pixel signal with a respective attenuation factor based upon the respective estimated noise level.
A computer-implemented method for reducing noise in a digital video signal from a sensor comprising a matrix of pixels generating a plurality of pixel signals, the method comprising:
- estimating a respective thermal noise level for each pixel signal in the plurality thereof based upon a first distribution;
- estimating a respective shot noise level for each pixel signal in the plurality thereof based upon a second Poisson distribution;
- estimating an average noise level associated with a group of pixel signals from the plurality thereof, the group of pixel signals defining at least a part of an image in the digital video signal;
- determining an average level of the group of pixel signals;
- determining a respective estimated noise level for the group of pixel signals by weighting the average noise level as a function of a ratio of the pixel signal and the average level of the group of pixel signals;
- estimating a respective noise level for each pixel signal by weighting the average noise level with a square root value of the ratio;
- and
- filtering each pixel signal with a respective attenuation factor based upon the respective estimated noise level.
Dependencies are inferred from the claim text.