MORPh: Mobile OLED power friendly camera system

With superior advantages of better display quality and power efficiency, the latest OLED technology has achieved unprecedented popularity in the display screen market. However, the OLED remains one of the most power-hungry components in mobile devices. Various optimization schemes have been proposed based on the color-dependent power consumption feature of OLED pixels. These schemes mainly focus on color modification during the playback phase and require significant overhead in terms of frame analysis and real-time modification. While such schemes are effective, the power saving opportunities during the camera recording phase are overlooked. To further enhance the power optimization, the camera parameters during the recording phase could be effectively utilized to reduce or eliminate the optimization overhead. Hence, we proposed MORPh, a cross-layer optimization system for OLED display in the smartphones. We analyze three fundamental parameters of smartphone camera system and their impact on the OLED screen power consumption. We then define corresponding metrics to quantitatively assess each parameter's potential of power saving guidance. Finally, we develop a set of schemes and integrated them into a video recording and playback application on an existing Android smartphone. The experiments results indicate power saving of 7.3%∼39.7%, and 20.3% on average while maintaining perceived visual quality.