1. A method for determining a pixel transformation function that maximizes backlight dimming while maintaining a pre-specified distortion level comprising: determining a minimum dynamic range of pixel values in a transformed image based on an original image (χ orig ) and the pre-specified distortion level; determining a scaling factor (κ) based on an adaptation luminance of the original image (L a orig ) and an adaptation luminance of the transformed image (L a DTM ); determining a human contrast sensitivity change (γ) between the original image and the transformed image; and deriving the pixel transformation function (ψ), wherein the pixel transformation function includes the scaling factor and the human contrast sensitivity change, and wherein the pixel transformation function produces the transformed image such that the perceived brightness of the transformed image is preserved while maintaining the minimum dynamic range, wherein ψ ⁡ ( χ orig ) = κ ⁡ ( L a orig , L a DTM ) · ( χ orig L a orig ) γ ⁡ ( L a orig , L a DTM ) .