基于调制度分割的物体轮廓有效测量区域自动识别方法

提出了采用调制度阈值分割技术进行物体轮廓有效测量区域自动识别的一种新方法,克服了投射条纹三维测量技术中由于阴影、条纹断裂、局部镜面反射、暗背景、采样不足以及外来的噪声等因素,使得被测物体表面存在无效测量区域(相位数据不可靠区域)的问题.采用了时域相位去包裹技术,保证了无效区域的相位数据不会影响到有效测量区域的相位数据.与有效测量区域相比,无效区域的调制度明显较低,对调制度直方图进行分析,借鉴图像分割的思想,采用了迭代算法自动求解最佳阈值,辨识物体轮廓测量的有效测量区域和无效测量区域,实现了单视角测量的自动化过程.车灯反射体测量实验证明了这种方法的优越性和可靠性.

Approach of automatically identifying valid measure-area by using modulation segmentation for 3D profilometry

An approach to identify the valid measure-area automatically by using threshold segmentation with respect to the modulation for 3D profilometry was provided. The existing fringe projection technique cannot effectively deal with the invalid measure-area due to local shadows,irregular reflectivity,fringe discontinuities,unlighted background,under-sampling,etc. The phase data from the invalid areas will have no effect on the data from the valid areas by using temporal phase unwrapping. The modulation from the invalid area is significantly lower than that from the valid measure-area. Deriving from the image segmentation concept,the method can calculate iteratively the optimal threshold of the segmentation for automatically identifying the valid measure-area by analyxing the modulation histogram. Thus it makes a single-view measurement procedure automatic. The resulting phase of a 3D shape of an automobile headlamp reflector is also presented to verify the advantages and the reliability of the method.