1. A method for processing images in a liquid crystal display, the method comprising: (a) acquiring a backlight index according to an image; (b) adjusting a backlight according to the backlight index; (c) acquiring a reference gray level according to the adjusted backlight, wherein the reference gray level lies in between a first gray level boundary and a second gray level boundary; (d) transferring a gray level of the image into a corresponding output gray level according to the backlight index when the gray level of the image lying in between the reference gray level and the first gray level boundary; and (e) transferring the gray level of the image into another corresponding output gray level according to a linear relationship when the gray level of the image lying in between the reference gray level and the second gray level boundary.