Patent ID: 7412109

Claim:
A method for filtering pixels in an image, comprising: partitioning a plurality of pixels in an input image into a plurality of blocks; identifying edge blocks in the plurality of blocks; determining a variance of an intensity for each pixel in each edge block; and filtering each pixel in each edge block with a filter that is dependent on the variance of the intensity of the pixel, in which the filter is a Gaussian function e −(a-b) 2 /2ξ 2 having a spread parameter ξ, and a window of size N, and a small variance corresponds to a small window and a small spread parameter ξ, and a large variance corresponds to a large window and large spread parameter ξ, and in which the filtering further comprises: setting the spread parameter ξ to fifteen and the window N to three if the variance is in a range of four to ten; setting the spread parameter ξ to thirty and the window N to five if the variance is in a range of ten to twenty-two; and setting the filter to an all-pass filter otherwise.