Abstract: Color correction is a key step for improving the visual effect of the projector display image and the understanding degree of the content, and a new correction algorithm is proposed based on color space conversion and Intensity Transfer Function（ITF）. This paper designs a 16×16 gray checkerboard as calibration image for sample; according to the mapping matrix of the projector-camera system, this paper solves the matching sampling points; it selects an empirical parametric curve to match the ITF, and estimates the parameters by the least squares method based on the sampling points; it calculates a color lookup table on the bases of the inverse function of the ITF, in order to achieve the color correction of the projection display image. In order to examine the feasibility and effectiveness, the proposed algorithm is implemented on an LCD projector. The test results show that this algorithm can achieve better display effect after correction, and it is simple and easy to use.

Key words: projection display, color correction, Intensity Transfer Function（ITF）, least square method

摘要： 颜色校正是提高投影显示图像视觉效果及内容感知理解程度的重要环节，针对此，提出了一种基于颜色空间变换和亮度响应函数（ITF）的颜色校正方法。设计一幅16×16的灰度渐变棋盘格作为标定图像，进行采样；利用测光表测量环境光，以调整相机拍摄参数；根据投影仪-相机系统映射关系矩阵，求解匹配采样点对；建立亮度响应曲线的经验参数模型，利用最小二乘法估计曲线参数；依据亮度响应曲线的反函数建立颜色查找表，从而实现投影显示图像的颜色失真校正。在LCD投影仪上进行了该算法的可行性和效果测试，实验结果表明：该算法校正后的投影画面质量较好，且实现简单。

关键词: 投影显示, 颜色校正, 亮度响应函数, 最小二乘法