Optimal Power Control Algorithms for Dynamic Global Backlight Dimming in LCD Panels

Abstract

In today’s trend of energy saving and environment protection, reducing the power consumption of consumer products has become a major concern during their design process. Since LCD is a dominant technology in the display market, this technology is not an exception to this rule. In the whole system, as the backlight is the part of the LCD panel that consumes the most of power, researches have been mainly focused on reducing its power consumption. However, reducing the power consumption of the panel by lowering the backlight brightness is not a simple task since it also means reducing the overall brightness of the displayed image.This thesis first presents two dynamic backlight dimming methods that enable to reduce the power consumption of the LCD panel by considering the input image characteristics. Indeed, these methods enable to reach a good compromise between power reduction and image quality preservation. Then, both methods are compared and the best one is designed and tested in hardware using Verilog HDL for FPGA implementation. Furthermore, research on the clipping perception is performed in order to model the distribution of the clipped pixels in a more accurate way than the PSNR metric, which was used to evaluate the performances of the two proposed methods.