提出了一种基于光线角度标定的被测面坐标测量方法。该方法以二维棋盘格参照物作为标定靶,测量得到外置光孔以及标靶上角点的坐标。将由角点过光孔的光线投影于世界坐标系各平面,计算出此光线与摄像机光轴的夹角。拍摄单幅图像,由Harris角点检测算法得到图像坐标系下角点坐标,以像素为单位插值,根据针孔相机原理,可得到CCD靶面上各像素点过光孔的光线与光轴的夹角,以此计算标定靶面上任意点的空间坐标。实验结果表明,该方法具有较高的精度。由于只需要拍摄一幅图像,因此可以完成实时测量。

A new method for optical coordinate measuring is proposed by using the angel between the ray emitted from CCD pixel and optical axis. The two-dimensional checkerboard reference act as a calibration target and the coordinates of the aperture and corner points of the checkerboard can be measured. The ray emitted from a pixel which goes through the aperture intersects a corner point on the checkerboard and project to planes in the world coordinate system, and the angle between the ray and camera axis can be worked out. From one picture, the corner coordinates on image coordinate system can be obtained by the Harris corner detection algorithm and the whole frame coordinates can be determined by interpolation algorithm. According to the principle of pinhole camera, the angel between the ray emitted from pixels on CCD and ray axis can be got, and then the space coordinates by the angel can be determined. Experimental results show that this method has a high accuracy. Since we only need to take a single picture, its can perform online measurements.