Abstract: Effect of extracting the center of light stripe of image directly affects the precision and efficiency of 3D coordinate measure on line structured light.A precise extracting method that combines the direction for image of light stripe and the gray barycenter method is proposed.Firstly，get the initial centers of stripe with threshold method.Secondly，calculate the normal direction of the light stripe with the method of the gray grads.Finally，detect the precise values on the normal direction by use of the gray barycenter method.It is proved that this extracting method can acutely and quickly detect the center，and the precision is sub pixel.

Key words: line structured light, gray grads, barycenter method

摘要： 线结构光三维坐标测量中，光条纹中心的精确快速提取直接影响测量精度与效率。提出了基于光条纹图像方向与重心法相结合的方法，首先用阈值法获取条纹中心初值，然后，通过光条纹图像的灰度梯度，计算条纹法线方向，最后，在法线方向用重心法提取光条纹重心。实验结果表明，该方法能快速精确地提取光条纹中心，精度达到亚像素级。

关键词: 线结构光, 灰度梯度, 重心法