Rank filter

Pixel operations

An image is represented as a matrix of pixel intensity values. When applying a rank-filter the pixel values in the defined area size are observed and ranked by the selected algorithm. All pixels in the observed area are set to the new calculated value.

With ranking filters, the grey values of the pixels in a defined area around a pixel are collected, sorted by size and ranked. A grey value is then selected from this sorted list to replace the grey value of the current pixel.

The Radius setting defines the size of the area to collect the pixels gray values in.