汇集点的计算方法研究

Study of the Computational Methods of Focus of Expansion

利用图像坐标计算交比,就可能出现计算故障或者引起计算精度的下降,采用N矢量表示视平面上的点和直线,建立交比的N矢量计算公式;在此基础上,研究了纯平移运动汇集点的N矢量计算方法,该公式只需要知道纯平移运动一个空间点在3个时刻t1、t2、t3的投影点或者该点的N矢量m、N速度m(t)以及加速度m(t),都可求出动点的汇集点。最后,通过举例分析和实验验证,证明该算法实用、可靠。

The computation of cross ratio by use of image coordinates will cause computational breakdown or deterioration of accuracy,and the N-vector formula for computing cross ratio is established if the points and lines on the image plane are represented in terms of N-vectors.The N-vector computational methods of a pure translation motion focus of expansion are constructed on the basis of the above study.The formula only needs the images of a space point at three different moments or its N-vector,N-rate and N-acceleration.The experimental result shows that this algorithm is more reliable.