1. A method comprising: making a first determination in a noise reduction processor as to whether a current pixel exhibits a ringing artifact; and determining, in the noise reduction processor, whether to apply a filtering process at said current pixel based on a result of said first determination; wherein: said first determination includes calculating four local complexity metrics at said current pixel; a first one of the complexity metrics is a sum of absolute differences between said current pixel and its nearest neighbors in an x-axis direction; a second one of the complexity metrics is a sum of absolute differences between said current pixel and its nearest neighbors in a y-axis direction; a third one of the complexity metrics is an absolute difference between nearest neighbors of said current pixel in said x-axis direction; and a fourth one of the complexity metrics is an absolute difference between nearest neighbors of said current pixel in said y-axis direction.