A study of change detection from satellite images using joint intensity histogram

Detection of appearance/disappearance of objects from satellite images is generally very difficult since background pixels also change their intensity values owing to various factors. In this paper we propose a method to estimate such background intensity changes by analyzing the joint intensity histogram of compared images. Considering the fact that background intensity changes tend to make clusters with ridges on the joint histogram, dominant ridges are detected using Hough transformation. Then, the joint histogram is classified into clusters according to the dominant ridges. Clusters of background intensity changes are distinguished based on covariance of each cluster Pixels showing intensity change other than the background intensity changes are extracted as candidates of "significant" change. The prospect of this method is examined through experiments using real satellite images.