线结构光条纹中心提取方法

Extraction Method of Light Stripe Center of Linear Structure

针对线结构光条纹中心提取的效率和精度影响测量结果的问题,提出一种主成分分析与灰度重心相结合的方法。首先对图像进行高斯卷积并采用阈值分割法初步提取图像中有效的光条纹信息;然后计算光条纹图像的梯度分布和幅值,选取幅值为零的点作为初始点;接着采用主成分分析法得到点的法线方向,沿法线方向在初始点两侧以幅值最大的两点作为边界点;最后采用灰度重心法求出边界内的光条纹中心以确定下一个初始点,通过迭代处理提取光条纹中心。在平均处理时间以及方均根误差方面对所提方法进行验证。实验结果表明,所提方法的平均处理时间约为1.701 s,提取精度比Steger法少0.0500 pixel。

In this study,a new extraction method combining principal component analysis and gray gravity center is proposed. The algorithm is used to solve the problem that the efficiency and accuracy of linear structured light stripe center extraction affect the measurement results. First,the image is subjected to Gaussian convolution. The threshold segmentation method is initially applied to extract the effective light stripe information from the image.Then,the gradient distribution and amplitude of the light stripe image are estimated,and the point with zero amplitude is considered to be the initial point. Subsequently,the principal component analysis is used to get the normal direction of the point. Along the normal direction,the two points with the maximum amplitude on both sides of the initial point are taken as boundary points. Finally,the gray center of gravity method is used to find the center of the light stripe within the boundary for determining the next initial point. The center of the light stripe is extracted through iteration. The proposed method is verified based on its average processing time and root mean square error.Experimental results show that the average processing time of the proposed method is approximately 1. 701 s.Furthermore,the extraction accuracy of the proposed method is less than 0. 0500 pixel compared with the Steger method.