Abstract：There is often a lot of important information in the low illumination images of a video surveillance system. In order to obtain the required information from low illumination images, this paper improved the quality of low illumination images. Considering the human visual resolution and enhancing the low illumination image, the hidden information from the low illumination image was extracted by using the method of nonlinear equalization, the absolute value of the difference between the image foreground pixel gray value and the background pixel gray value, and the balance factors. This method can improve the compensation iterative speed to quickly obtain the image needed by optimizing the compensation factor in the course of the piecewise nonlinearity on an image gray spectrum.

Keyword：piecewise;nonlinearity;optimization compensation;low illumination;