基于灭点标定的立体视觉自由曲面测量

利用基于灭点理论的方法进行系统的非线性标定，采用投射光斑法增加自由曲面的图像特征；提出了一种基于方向和距离约束的分片排列编码方法，对投影光斑进行排列编码。首先分别在左右图像上根据彩色点的位置关系自动确定一个初始匹配点和四个匹配方向，然后对其余点按照分片排列法进行自动排列编码。对石膏像的面部进行了三维测量和重构实验。实验表明，基于方向和距离约束的分片排列编码法，可以准确的进行投影点的编码, 并能够快速、有效地实现彩色图像特征点的全自动匹配。

3-D Measurement of free-form surfaces with stereo vision based on vanishing-point calibration

The nonlinear calibration for camera was applied to two view-point 3D reconstruct system using vanishing-point. The image features of a free-form surface were enhanced by means of projecting arrays of dots. An array coded algorithm of direction and distance restricted was presented for projecting dots. First, get an original matching point and four original matching directions automatically according to the positions of red points. Then, all other white dots viewed both in two images can be coded by the proposed method and the images in two directions can be matched automatically. The experiments of 3D measurement and reconstruction of plaster model indicated that a sub-pixel precision can be got by using the algorithm of nonlinear vanishing-point calibration and the array code method based on direction and distance restricted can coding the projective point on picture rightly and can performs matching effectively between two images.