Aiming at drawback of high computation complexity of multi-scale Retinex, an algorithm for contrast enhancement of image which simulates visual characteristics of human eyes is proposed. According to Retinex model, the image is separated into illumination and reflection component. And two nonlinear transformation functions are introduced to modify illumination and reflection components of the image respectively. And the global contrast enhancement function that adopts logarithm transform could stretch illumination component, so whole visual appearance is improved. Then reflection component is adjusted by nonlinear function that involves discriminating ability of image gray level for human eye, consequently local contrast of image is enhanced. Experiments show that our method does not cause color distortion for RGB and some chroma-luminant color spaces, visual appearance is well, and operation cost is lower than that of Multi-Scale Retinex (MSR).