Enhancement of Backlight-Scaled Images

Tai-Hsiang Huang, Kuang-Tsu Shih, Su-Ling Yeh, Homer H. Chen
2013 IEEE Transactions on Image Processing  
Switching the liquid crystal display (LCD) backlight of a portable multimedia device to a low power level saves energy but results in poor image quality especially for the low-luminance image areas. In this paper, we propose an image enhancement algorithm that overcomes such effects of dim LCD backlight by taking the human visual property into consideration. It boosts the luminance of image areas below the perceptual threshold while preserving the contrast of the other image areas. We apply the
more » ... just noticeable difference theory and decompose an image into an HVS response layer and a background luminance layer. The boosting and compression processes, which enhance the visibility of the low-luminance image areas, are carried out in the background luminance layer to avoid luminance gradient reversal and over-compensation. The contrast of the processed image is further enhanced by exploiting the Craik-O'Brein-Cornsweet visual illusion. Experimental results are provided to show the performance of the proposed algorithm. Index Terms-LCD backlight, ambient light, image enhancement, human visual system, contrast, JND. 1057-7149 © 2013 IEEE
doi:10.1109/tip.2013.2272517 pmid:23864206 fatcat:gzowdx3fuzelxb7fnopdvk5uu4