Method and system for regulating image brightness

The invention is applicable to the field of image processing, and provides a method for adjusting image brightness and a system thereof. The method comprises the following steps: acquiring a gray value interval according to the width of the gray level; acquiring the number of pixels corresponding to the gray value interval, and acquiring a compact interval according to the number of the pixels corresponding to the gray value interval; acquiring a value span of an accommodation coefficient according to the compact interval; and adjusting the gray value of the pixels of the image according to the accommodation coefficient of the value span. The method and the system realize improvement on the brightness of a dark image under general illumination, thereby flexibly and conveniently acquiring ahigh-quality image.