S曲线全局调光算法能够降低LED液晶显示器的功耗并提高显示图像静态对比度, 为了进一步提高节能率, 提出了基于S曲线的两级动态调光算法。首先对输入图像的所有像素分量进行线性放大, 将输入图像的像素灰度级整体提升; 然后利用S曲线对线性放大后的图像进行像素补偿, 同时输出调整后的背光亮度信号。对40幅典型图像进行了仿真, 结果表明: 平均背光节能30%, 静态对比度提高33%。开发了工程样机,对6类常见的电视节目进行测试, 整机平均节能25.1%, 静态对比度提高了30%。与S曲线全局调光算法相比, 所提算法在显示性能保持不变的同时, 能进一步将节能率提高10%。

S-curve global dimming algorithm can reduce the power consumption of LED-lit Liquid Crystal Display (LCD) and improve the static contrast of display images.In order to further increase the power-saving efficiency,a two-step dynamic dimming algorithm based on S-curve is proposed.First,the gray levels of all sub-pixels of the input image are adjusted according to the maximum gray level,the pixel gray levels of input image are upgraded on the whole.Then,the pixel compensation is performed to the linearly amplified image with S-curve,and backlight brightness signals after adjustment are output at the same time.The simulation results of 40 typical images show that: the average backlight power is saved by 30%,and the static contrast is increased by 33%.The engineering prototype is developed to test six common TV programs.The result shows that the overall average power-saving is 25.1%,and the static contrast is increased by 30%.Compared with S-curve global dimming algorithm,the proposed algorithm can further increase the power-saving efficiency by 10% while maintaining the same display performance.