Content-adaptive display power saving in internet mobile streaming

Backlight scaling is a technique proposed to reduce the display panel power consumption by strategically dimming the backlight. However, for Internet streaming to mobile devices, a computationally intensive luminance compensation step must be performed in combination with backlight scaling to maintain the perceived appearance of video frames. This step, if done by the CPU, could easily offset the power savings via backlight dimming. Furthermore, computing the backlight scaling values requires per-frame luminance information, which is typically too energy intensive to compute on mobile devices. In this paper, we propose Content-Adaptive Display (CAD) for Internet mobile streaming. CAD uses the mobile device's GPU rather than the CPU to perform luminance compensation at reduced power consumption. Backlight scaling schedule is computed using a more efficient dynamic programming algorithm than existing work. We implement CAD within an Android app and use a Monsoon power meter to measure the real power consumption. Experiments are conducted on more than 470 randomly selected YouTube videos, and results show that CAD can effectively produce power savings.