1. A method of adjusting image intensity to compensate backlight dimming in dynamic backlight control, comprising the steps of: estimating distortion of an image that corresponds to different mapping index values (X C ) selected from intensity levels of said image, wherein said estimating distortion of said image is based on factors including: the quantity of pixels that have intensity exceeding said mapping index value; and the amount that the intensity of each said pixel exceeds the corresponding mapping index value; and selecting from a plurality of schemes for adjusting image intensity to minimize overall resulting distortion, wherein said plurality of schemes are based on the minimum mapping index value corresponding to a maximum compromised quality value (Q C — MAX ) of said image for an application, the minimum of mapping index value being determined by computing distortion corresponding to mapping index values according to ∑ i = Xc N ⁢ ( i - X c ) γ ⁢ F ⁡ ( i ) , and finding the minimum mapping index value according to Q C ⁢ _ ⁢ MAX ≥ ( N X c ) γ · ∑ i = Xc N ⁢ ( i - X c ) γ ⁢ F ⁡ ( i ) , where γ is the gamma factor of a display for displaying the image, F(i) is the pixel value distribution function of the image to be displayed, and N is the number of intensity levels.