液晶显示器阶调复现特性校正与优化研究

为了改变液晶显示器(LCD)的阶调复现特性,改善其显示图像的视觉效果,建立了一套自动γ校正系统,将实测阶调复现曲线(TRC)与以分段选取γ值方式得到的目标曲线对比,通过逐行修改显示器驱动电路中的数字查找表(LUT),使实测曲线逐步逼近目标曲线并最终与之重合。测试结果表明,校正后的LCD阶调复现特性符合预设模型,且以幂函数模型对LCD加以校正,输出图像的各层次均清晰可辨,而以适当选取拟合参数的分段函数模型的弓形曲线校正LCD,可使显示图像的平均亮度比幂函数模型提高50%以上,且TRC曲线中间区域亮度输出变化率更大,图像层次更为清晰,颜色亮丽。

Correction and Optimization Research of LCD Tone Reproduction Characteristics

In order to change the tone response characteristics of Liquid Crystal Display(LCD) and enhance visual effect of the image under different lighting environments, a automatic γ correction system is established.Through contrasting the measured Tone Reproduction Curve(TRC) with the target curves which get different γ in different areas, progressive modification should be made to the digital Look Up Table(LUT) in the driving circuit of the displayer, so that the measured curve would constantly approach the target one.Experimental results show that the tone response characteristics accord with the models pre-established, and when LCD is corrected to power-law function, every luminance level of image would be clear.On the other hand, when LCD is corrected to piecewise function with reasonable parameters, the average luminance of image would increase more than 50 percent as above.Also the change rate of the output luminance for the moderate area becames much higher, making an improvement of the gradation.