A method for improving motion blur and contour shadow of a display displaying images having a number of frames includes transforming a second average gray scale into a third average gray scale when a first average gray scale for displaying a first frame is unequal to the second average gray scale for displaying a second frame. A luminance corresponding to the second frame is generated according to the third average gray scale and at least one luminance query table. The third average gray scale is greater than the first average gray scale and the second average gray scale or less than the first average gray scale and the second average gray scale.