MobiSLIC: Content-aware energy saving for educational videos on mobile devices

We present a context-aware system that simultaneously increases energy-efficiency and readability for educational videos on smartphones with OLED displays. Our system analyzes the content of each frame of the video and intelligently modifies the colors and presentations of specific regions of the frame to drastically reduce display energy consumption while retaining relevant content of the lecture video. We achieve this by leveraging the mapping between frames and electronic versions of slides used in the lecture. This enables separate manipulation of the slide area and the background. Further, since the slides can themselves be analyzed for content (e.g. text and images within) this approach provides substantive control over energy use and user experience. We evaluate the system using extensive energy measurements performed on phones using two different display technologies. Our method was able to reduce energy usage up to 59.2 % of the energy used by the display which amounts to 27 % of the total energy used by the device.