Modified wallis filter for improving the local contrast of GIS related images

摘要

Disclosed herein is a method and system for performing adaptive local contrast enhancement for an image by using a linear complexity algorithm for Wallis filter. For an input image, the standard deviation and mean are computed for the first pixel in the image. The computed standard deviation and mean of the first pixel are re-used to calculate the standard deviation and mean for the nearest pixels. So, the standard deviation and mean for each pixel in the image are based on the computed standard deviation and mean of at least one other pixel in the image.