In this paper, we propose a method to adjust the reference point of the existing work for gray-level mapping between the input and output image, to balance between image quality and power consumption in OLED (organic light-emitting diode). The proposed algorithm is aiming to achieve good balance between video quality and power consumption. The experiment results show that our work is better than the state-of-the-art work by 0.0357×10^9 lower power consumption in the case when the target PSNR is 30dB, and 0.007×10^9 lower power consumption in the case when the target PSNR is 40dB, where the image quality is kept similar for all methods.