Dynamic clipping ratio determination for global backlight dimming in LCD

This paper proposes a dynamic global backlight dimming algorithm based on the analysis of the cumulative distribution function (CDF) of the image histogram. For each intensity level, the convexity of the CDF is calculated using the distance to the uniform histogram curve. Using these values, the proposed algorithm characterizes the shape of the CDF to find the proper clipping ratio. This ratio enables to get the maximum level data beyond which the intensity levels are clipped, as the results of backlight dimming but image distortion. The experimental results show that the proposed algorithm gives a good compromise between backlight power reduction and image quality preservation, quantified by the PSNR metric.