投影显示亮度均匀性稳健校正方法

Robust Correction Method for Projection Display Luminance Uniformity

随着投影仪的发展,其显示质量越来越受到人们关注。投影显示中普遍存在亮度不均匀性问题,且大部分高灰度图像在亮度校正后易出现饱和。而一般的剪切法会极大地降低像面均匀性。为解决这个问题,基于投影仪相机系统建立系统光度学模型,在传统线性映射方法的基础上提出了一种亮度不均匀性校正的非线性稳定算法。实验表明,采用的投影仪在校正前其图像显示亮度从中心到边缘下降了近50%,像面不均匀性的相对均方根误差(RRMS)为17.7%;而饱和图像校正后像面的RRMS为1.69%,几乎达到了与未饱和图像(1.55%)相同的校正精度,同时基本保持了显示图像的平均亮度水平。

With the development of projectors, the display quality has been widely concerned. The luminance uniformity is a common problem in projection display. Most images with high gray value tend to saturate after uniformity correction, while the common clipping method will decrease the uniformity greatly. In order to solve this problem, a photometric model based on projector-camera system was set up, and then a robust nonlinear algorithm for luminance uniformity correction was proposed on the basis of the traditional linear mapping method. The experimental results indicate that the display luminance of the projector is decreased by 50% from center to edge, corresponding to the relative root mean square （RRMS） error of luminance uniformity of 17.7 %. After luminance correction, the RRMS value of saturated images decreases to 1.69 %, almost as good as that for nonsaturated images （1.55%）, while the average luminance level is well preserved in general.