An apparatus and method to enhance a contrast includes a first operation part, a second operation part, and a mapping part. The first operation part calculates an average and a standard deviation of an input image. The second operation part calculates an average and a standard deviation of a target image based on the average and the standard deviation of the input image. The mapping part converts a pixel value of the input image by a mapping function generated by receiving the averages and the standard deviations of the input image and the target image from the first operation part and the second operation part, respectively, and outputs a pixel value of an output image.