基于结构光技术的高光表面三维测量方法

Shiny Surfaces Measurement Based on Structured Light System

分析了结构光技术对高光表面无法完整测量的原因,提出一种双目多次曝光测量和投影仪-摄像机单目测量相结合的三维测量方法。双目结构光系统中的两个相机采用不同的曝光时间采集一系列光栅条纹,并从每次曝光中选择高质量像素解相。将每次曝光的选择结果拼合成一张完整的相位图,并通过三角原理法计算三维坐标。双目结构只对左右相机可视区域测量,投影仪-摄像机单目测量避免了由于某个单摄像机视线存在高光或遮挡等原因引起的三维测量数据缺失问题,有效提高了测量结果的完整性。实验表明,上述方法测量高光表面具有良好的效果,系统测量精度可达0.06mm。

Shiny surfaces or reflecting surfaces have been a big challenge for any optical methods to directly acquire 3-D information of their whole surface.This paper analyses the reason why it can not be measured completely by structured-light.A method by combining multiple exposures with the projector and a single camera as a monocular measurement unit was presented.The structured light binocular vision system used two cameras to catch a sequence of fringe images with different exposures,and only corresponding high-quality phases from one exposure could be measured each time.The obtained high-quality phases from all exposures were then merged together to generate the complete phase map which could be converted to 3-D coordinates by triangulation technique.However,only the public areas of two cameras could be reconstructed by binocular system used multiple exposures.A monocular measurement combining the projector and a single camera can further avoid point losing caused by the highlight and occlusion in a single camera.Experimental results proved that the proposed method could successfully measure shiny or reflecting objects with a high accuracy up to 0.06mm.