室外场景光照估计的基图像分解算法  

Basis Image Decomposition for Outdoor Lighting Estimation

作　　者：张锐[1,2] 钟凡[1,3] 彭群生[4] 秦学英[1,3] 

机构地区：[1]山东大学计算机科学与技术学院,济南250101 [2]山东财经大学计算机科学与技术学院,济南250014 [3]山东省软件工程重点实验室,济南250101 [4]浙江大学CAD&CG国家重点实验室,杭州310027

出　　处：《计算机辅助设计与图形学学报》2013年第4期442-449,共8页Journal of Computer-Aided Design & Computer Graphics

基　　金：国家"九七三"重点基础研究发展计划项目(2009CB320802);国家自然科学基金广东省联合基金资助项目(U1035004);国家自然科学基金(61173070;61272431);中国博士后科学基金(2012M511509);山东省杰出青年基金(JQ200920)

摘　　要：基于室外固定场景的太阳光与天空光基图像分解理论,证明了同一太阳方位在不同天气情况下的3幅图像具有线性相关性,使得基图像方程欠约束,导致基图像无法自动求解.为此提出利用2个太阳方位、2种天气情况下的4幅图像求解基图像的算法,并利用太阳光与天空光基图像在太阳光照区域内点的像素色调一致性,优化基图像及太阳光和天空光光照参数.实验结果表明,该算法自动求解基图像,且根据基图像和光照系数准确重构原图像的均方误差,并将其控制在2像素值以内,从而可用于高品质的增强现实技术.Based on the theory of the basis image decomposition of the sunlight and the skylight for fixed outdoor scenes, we prove that three images captured with the same sun position under different weather conditions show linear correlation. Therefore, the basis image equations are the systems of under-constraint so that they can not be solved automatically. In this paper, we present the algorithm of solving basis images using four images with two sun positions under two kinds of weather conditions. In addition, the hue consistency of pixels in the sun area between the basis images of the sunlight and the skylight is used to optimize basis images and illumination parameters. The experimental results show that basis images can be solved automatically and the original images can be reconstructed accurately according to basis images and illumination parameters. Hence, it is suitable for augmented reality with high quality.

关 键 词：基图像分解 光照估计 色调一致性 增强现实 

分 类 号：TP391[自动化与计算机技术—计算机应用技术]