1. A method for simulating dark-part exposure compensation of high dynamic range images using a single image, comprising steps of: obtaining an image P 0 ; performing bright-part-enhancing image processing on the image P 0 to obtain an image P 1 and further performing saturation-contrast-enhancing image processing on the image P 0 to obtain an image P 2 ; selecting one of the image P 1 and the image P 2 , performing bright and dark parts identifying image processing on the selected image selected from the image P 1 and the image P 2 , performing blurring image processing on the selected image, so as to obtain a weight-reference image P 3 , wherein each of a plurality of pixel values of the weight-reference image P 3 represents a weight; and performing mixed weight calculation on a plurality of pixels of the image P 1 and a plurality of pixels of the image P 2 according to a plurality of weights of a plurality of pixels of the weight-reference image P 3 , respectively, so as to mix the image P 1 and the image P 2 to obtain a mixed image P 4 , wherein the pixels of the images P 1 , P 2 on which the mixed weight calculation is performed correspond to the pixels of the weight-reference image P 3 , respectively.