The Rank Filter amplifies faint detail by replacing each pixel by its position or rank within the sorted list of the values of its neighbours within a specified Radius. This procedure accentuates small differences among nearby pixels at the cost of the loss of information about the relative brightnesses of pixels separated from each other by greater distances.
Because the rank filter algorithm is intrinsically very harsh, its effect usually has to be diluted by mixing it with the original image, thereby preserving more of the information about large-scale brightness variations across the image. The Weight controls how strongly the filter is applied.
Availability of this feature depends on Product Level.