Performance of a similarity measure in grayscale image matching

Kullback-Leiber divergence measure is one of the commonly used distance measure that is used for computing the dissimilarity score between histograms. In this paper we show that it produces biased results when correlation is computed between gray scale images or sections of images using their histograms. The biased is explored and demonstrated through numerous experiments with different sizes of objects and different kind of movements between the pairs of images i.e., slow moving, first moving, rotating bodies etc, in cluttered and less cluttered environments. The performance of the Kullback-Leiber divergence measure is compared with a pixel based spatial matching criterion.