Dynamic shadow compensation of aerial images based on color and spatial analysis

This paper describes a method that can improve the visibility of features in shadowed regions in urban aerial images while retaining nonshadowed regions and the natural tint of shadowed regions automatically. The method first calculates the posteriori probabilities of each pixel belonging to shadowed class or nonshadowed class using color features from a low-frequency component image, and then compensates the intensity and saturation of each pixel in shadowed regions according to the posteriori probabilities. Experimental results indicate the effectiveness of proposed method.