“…In [2,8,22,23,39], different techniques are presented to calculate coefficients used to determine the filter output as a combination of the vectors in the filtering window. Approaches which use some weights to perform a weighted vector median operation are proposed in [17,19,24,28]. In [1,4,20,26,27,38], the authors propose to determine first if the vector in consideration is likely to be noisy using cluster analysis, [1], a test respect to the mean of the vectors in the window, [20], a statistical test respect to the mean or median of the vectors, [4,26,27], and then apply the filtering operation only to those noisy pixels.…”