作者：董建民, 李东晶

作者单位：山东工业职业学院, 山东 淄博 256414

关键词：三维测量;校准;相位计算;直线拟合

摘要：

针对现有投影仪-相机结构光测量系统标定算法准确度不高的问题,提出一种基于直线拟合的高准确度标定算法。该算法首先找到系统灰度响应线性度较好的灰度区间,在该区间内采用三频四步相移算法对相机获取的投影光栅图像进行相位恢复。然后计算出棋盘格角点在相机坐标系中的坐标,并找到这些角点在投影仪图像中的对应像素点,通过直线拟合的方法进行优化,提高匹配点的搜索准确度。最后采用双目视觉的标定方法实现投影结构光系统的标定。系统标定实验的结果验证所提出的基于直线拟合的标定算法具有较高的标定准确度,有助于后续高准确度的三维重建与测量。

Accurate calibration algorithm for structure light system based on line fitting

DONG Jianmin, LI Dongjing

Shandong Vocational College of Industry, Zibo 256414, China

Abstract: An accurate calibration algorithm for projector-camera structure-lighted measuring system has been proposed to improve the accuracy of traditional calibration algorithms. First, find out gray intervals with nearly linear grayscale response. Second, calculate the phase of the projected image by using triple-frequency four-step phase shifting method in the selected interval. Third, extract checkerboard corners from the images captured by the camera, and find out corresponding pixels of these corners in the projector image. Fifth, increase the searching precision of correspondences with the line fitting method. The last step, calibrate the projected structure light system by means of standard stereo. The experiments demonstrate that the proposed algorithm is accurate and satisfies the requirements of three dimensional reconstruction and measurement systems.

Keywords: three-dimensional measurement;calibration;phase calculation;line fitting

2015, 41(8): 88-93  收稿日期: 2015-1-1;收到修改稿日期: 2015-3-18

基金项目: 国家863计划资助项目(2011AA040902)

作者简介: 董建民(1979-),男,讲师,硕士,主要从事图像处理、光学测量方面的研究。

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