A method of processing an image includes the steps of separating an image into multiple color channels, and dividing the image into multiple zones, in which each zone includes a sub-array of pixels. The method then calculates a color shading profile for each zone. The color shading profile is calculated as a linear function, typically a straight line. If a linear function cannot be determined for that zone, the method interprets a function for that zone using the nearest zone neighbors. The method corrects the color shading using the functions calculated for the respective zones.