Human Visual System Based Multi-Histogram Equalization for Non-Uniform Illumination and Shoadow Correction

Images that do not have uniform brightness pose a challenging problem for image enhancement systems. As histogram equalization has been successfully used to correct for uniform brightness problems, we propose a new histogram equalization method that utilizes human visual system based thresholding as well as logarithmic processing techniques. Whereas previous histogram equalization methods have been limited in their ability to enhance these images, we demonstrate the effectiveness of this new method by enhancing a range of images with shadowing effects and inconsistent illumination. The images shown include images captured professionally and with cell phone cameras. Comparison with other methods are presented.