A method (50) and apparatus (40) for reducing noise in a video signal calculates (53) a discrimination value of a filter based on a magnitude difference between a current frame and a prior frame of a sequence of frames and modifies (54) the current frame using the modified discrimination value. The output of the filter is calculated as follows: g(i, j, k)=f(i, j, k).+-..beta. wherein: f (i, j, k) is the current frame input to the filter; g(i, j, k) is the current frame output from the filter; and .beta. is the discrimination value of the filter, which is calculated as follows: .beta..kappa..delta.'.chi..delta.'.times..delta..delta..delta.<.delta.- .delta..gtoreq..delta. ##EQU00001## in which: .kappa. and .chi. are constants less than one; .delta. is a magnitude difference between the current frame and the prior frame; and .delta..sub.0 and .delta..sub.1 are constants that satisfy .delta..sub.0.ltoreq..delta..sub.1.
