Image integrity-based gray-level error control for low power liquid crystal displays

In this paper, we present a new approach to dynamic gray-level error control for global dimming of liquid crystal display (LCD) devices. In the LCD devices, global dimming is used to reduce power consumption by limiting the maximum luminance and lowering the brightness of backlight. The existing approaches, based on the fixed rate of clipped pixels, deteriorate the image quality seriously for some images even after gray level compensation. The proposed approach, on the other hand, dynamically chooses the maximum luminance for a given image, based on final image integrity. Thus, it has an advantage of preserving the worst image quality at any desired level, while reducing power consumption as much as possible. In the experiments, the proposed approach successfully maintained the minimum target peak signal to noise ratio (PSNR) for test sequences.