Backlight power reduction using efficient image compensation for mobile devices

Since backlight dimming widely used for power reduction of mobile devices degrades the image quality in brightness and contrast, image enhancement is exploited to compensate the degradation. In this paper, we propose a novel backlight power reduction scheme using an efficient image compensation algorithm that scales discrete cosine transform (DCT) coefficients of image in the compressed domain. To reduce the computational burden of the conventional backlight dimming method where decompression is performed prior to image compensation in the spatial domain, we introduce a computationally efficient image compensation algorithm that processes only dominant DCT coefficients of images using a mapping function in the DCT domain. Experimental results indicate that our proposed method provides higher visual quality with reduced complexity as compared to conventional image compensation schemes.