Projected Fringe Profilometry of Combining Binocular and Monocular Vision Technique for Specular Surface Measurement

【摘要】：A combined method of binocular and m onocular vision technique for projected fringe profilometry is proposed to allow a traditional structured light binocular vision system to perform high-quality whole-field measurement of specular surfac e.To reduce the degradation in area-based correlation caused by specular highlights,we first detect the m in stereo images using a correspondence uncertainty measure,and then disregard these sp ecular points in computation of matching costs.Then,to solve this problem and further obtain unmatched area data,this binocular vision sy stem was also used as two ca mera-projector monocular systems worked from different viewing angles at the same time to fill in missing data in the binocular reconstruction.This m ethod involves producing measurable images by integrating such techniques as multiple exposures,high dynamic range(HDR) imaging to ensure the capture of high-quality phase of each point.An image segmentation technique was als o introduced to decide the suitable m onocular system to reconstruct the lost points accurately as to a certain point self-adaptively.Our approach uses a traditional dual-camera structured light system.The techniques of multiple exposures,high d ynamic range imaging and an adding constraint to lim it the variance of specular intensity difference are all unified and generalized to leads to insights regarding solutions to the traditional problems of dealing with specular surfaces by individual techniques.Differing from the fore mentioned fringe-based te chniques,we have developed a practic al technique of combination of both binocular and monocular reconstruction to deal with some parts of highly specular surfaces with large reflectivity variations which may be too shiny or dark to measure by all the mentioned methods.These improvements now make it suitable for a traditional structured light binocular vision system to perform high-quality whole-field surface measure of specular surfaces without increasing the hardware cost.To suggest the practical utility of the method,experiments showed that our consideration of specular reflections extended the mea surable areas on the obje cts to the w hole projectorilluminated field with high accuracy.