TFT LCDs are a dominant display device currently but have significant power consumption due to backlight units. Many dimming techniques have been studied to achieve high power saving while maintaining image/video quality. However, they often fail to associate the amount of power saving with the human perceptuality of image quality organically. In this paper, we propose a novel approach of combining color transformation and dimming synergistically in the aspects of both power saving and image quality. This approach adaptively selects an allowable perceptual value depending on the luminance value of an image (or a frame) and does backlight dimming based on it. The technique is implemented using an image viewer and a video playback program on an LED backlight unit-based TFT LCD board. Experimental results show that our approach achieves on average 34.5% and 21.19% power savings for still images and video files, respectively, without affecting the visual quality of the images and with an overhead of 4.09% for video files.
