基于成像模拟法的镜面体表面三维测量

Imaging Simulation Method for Specular Surface Measurement

针对计算机视觉对表面光滑且连续的镜面体三维外形测量中存在的难题,提出一种基于成像模拟法的测量方法。分析镜面反射的几何光学原理,根据镜面体表面光线反射的特性,使用相机和液晶显示器组成测量装置对镜面物体进行测量。使用平面镜对相机和显示器进行参数标定,并使用时间相移法对显示器上的像素点进行编码,从相机拍摄的镜面物体反射的条纹图像出发,采用光线逆跟踪方法,使用参数曲面反向模拟镜面物体的反光过程,通过调整曲面参数使得模拟的反射光线和显示器交点与实际位置距离误差最小,即可获得镜面体表面的三维数据。通过试验验证了该方法的有效性,具有较高的测量精度。

To solve the problems in computer vision based measurement for smooth and continuous specular surface, an imaging simulation measurement method is proposed. The geometrical optics principle for specular surface is studied. A setup which consists of a camera and a LCD display is used to measure the specular objects. A parametric surface is used to simulate the specular surface whose optics property is similar to a smooth curved surface. A simulation incident light ray which is determined by the original point of the camera and the pixel on the image plane reaches the parametric surface, then is reflected by the law of reflection. The 3D points of the specular surface are obtained when the errors between the intersections of simulation reflect rays and the real points of the LCD display are minimized. The experiment results show that this method is effective and obtains high accuracy.