The present invention describes enhancing image contrast comprising the following steps: determining a segmentation point according to at least one segmentation threshold and pixel statistical data of a picture, wherein the segmentation point is utilized to divide the pixel statistical data into a first partial statistical data and a second partial statistical data; and determining a first partial brightness conversion function and a second partial brightness conversion function according to the first and the second partial statistical data, respectively. The first partial brightness conversion function is used to adjust brightness values of multiple pixels in the picture corresponding to the first partial statistical data, and the second partial brightness conversion function is used to adjust brightness values of multiple pixels in the picture corresponding to the second partial statistical data.