Adaptive local contrast enhancement of high dynamic range image

Most existing global contrast enhancement algorithm can not deal with high dynamic range images. Thus a simplified logarithmic transformation equation has been proposed in this paper. A partially overlapped sub-block method is also adopted to perform local contrast enhancement. For purpose of optimization, two contrast measures are used for finding optimal transformation parameters. They merge into a new algorithm, called POSLT (partially overlapped sub-block logarithmic transformation). POSLT exhibits good performance and controllability even if it has high computational complexity. Our experimental results give firmly support of POSLT.