基于法向量估计的透明物体表面反射光分离  

Reflected Light Separation on Transparent Object Surface Based on Normal Vector Estimation

作　　者：张景华 张焱[1] 石志广[1] 李飚[1] 张宇[1] 刘荻 索玉昌 Zhang Jinghua;Zhang Yan;Shi Zhiguang;Li Biao;Zhang Yu;Liu Di;Suo Yuchang(National Key Laboratory of Science and Technology on Automatic Target Recognition,College of Electronic Science and Technology,National University of Defense Technology,Changsha,Hunan 410073,China)

机构地区：[1]国防科技大学电子科学学院ATR重点实验室,湖南长沙410073

出　　处：《光学学报》2021年第15期206-218,共13页Acta Optica Sinica

基　　金：国家自然科学基金(62075239,61302145);武器装备预研项目(9140C800302KG01)。

摘　　要：首先,利用透明物体表面反射光和透射光在垂直和平行方向上的光强分布关系,基于偏振正交分解原理,推导出反射光成分、透射光成分、反射光偏振度、透射光偏振度之间的函数关系。然后,根据相机成像原理,利用表面法向量求解得到透明物体表面不同位置处入射光线和法向量的夹角及入射面方位角,进而归纳出图像中各个像素点的反射光偏振度和透射光偏振度的分布规律。最后,基于反射和透射的偏振特性和相关特性,利用梯度下降算法计算得到反射分量和透射分量之间归一化的互相关最小值,最终实现反射光和透射光的分离,进而抑制了透明物体表面反射光的干扰,这为复杂反射光场景下的目标检测识别及图像匹配等提供了支持。Firstly, according to intensity distributions of reflected light and transmitted light in perpendicular and parallel directions on surface of transparent objects, the functional relation between the components of reflected light and transmitted light and that between the polarization degrees of reflected light and transmitted light are derived with the principle of polarization orthogonal decomposition in this paper. Then, based on the imaging principle of camera, the angles between incident lights and normal vectors and the azimuth angles of the incident planes at different positions of transparent object surface are obtained by using surface normal vector to summary the distribution rules of the polarization degrees of reflected light and transmitted light at each pixel in the image. Finally, according to the polarization characteristics and correlation features between reflection and transmission, the minimum of normalized cross-correlation between reflection component and transmission component is calculated by gradient descent algorithm to realize the separation of reflected light and transmitted light, which suppresses the interference of reflected light on the surface of transparent objects, and it plays an important role in information processing and applications such as target detection and image matching in environment with complex reflected light.

关 键 词：物理光学 法向量 透明物体 偏振特征 相关特征 反射光分离 

分 类 号：TP391[自动化与计算机技术—计算机应用技术]