Patent ID: 7418149

Claim:
An apparatus for reducing multiple noise types in a video input signal, said apparatus comprising: a noise power converter for receiving and using said video input signal, a variance of additive noise, a variance of multiplicative noise and an indication of a type of noise for estimating an equivalent additive noise variance signal; a temporal recursive filter using said equivalent additive noise variance and said video input signal for generating a temporally filtered video signal and a residual noise variance signal; a spatial noise reducer using said residual noise variance signal and said temporally filtered video signal for spatially filtering said video input signal to provide a video output signal having reduced noise; and wherein said noise power converter comprises a low pass filter for filtering said video input signal to provide a low pass filtered signal; a shape adaptive window for receiving and using said low pass filtered signal, and a given threshold tolerance for calculating a binary signal ωij(c,r) representing local classification results within said threshold tolerance and a signal N(c,r) indicative of similar pixels in said window; a shape adaptive window mean estimator using said binary signal ωij(c,r), said N(c,r) signal and said video input signal for calculating a local estimated means signal value μY(c,r) given by μ Y ⁡ ( c , r ) = ( 1 / N ⁡ ( c , r ) ) ⁢ ∑ i ⁢ ∑ j ⁢ Y ij ⁡ ( c , r ) ⁢ ω ij ⁡ ( c , r ) ; and an equivalent additive noise variance calculator using said local estimated means signal value μY(c,r), said variance of additive noise, said variance of multiplicative noise and said indication of a type of noise for calculating said equivalent additive noise variance signal.