Abstract: To enhance the dark areas of an image, a novel algorithm to enhance the color image based on global and local adaptation of the human visual regulation principles is proposed.The algorithm mainly consists of three parts: a preliminary global luminance adjustment followed by local contrast enhancement and color restoration. The global luminance adjustment increases the luminance of darker pixels based on nonlinear adaptive histogram stretching. The local contrast enhancement adjusts the intensity of each pixel based on its relative magnitude, which is based on its correlation between relative magnitude and the output of its neighboring pixels. Then an adaptive nonlinear color restoration process is applied to convert the enhanced intensity image back to a color image. The contrast experimental results based on a large set of images indicate that, the proposed image enhancement algorithm is adaptive, effective and rapid.

Key words: human visual regulation principles, preliminary luminance adjustment, local contrast enhancement, color restoration, rapid