Research On Optical Measuring Technique For 3D Profile Of Spectacle Frames

As the development of 3D measurement technology,there are more and more applications in our life.At the present,the 3D measurement technology is applied in many fields,like medical diagnosis,industrial manufacturing,space exploration,preservation of cultural relics and so on.When we measure the 3d structure of the spectacle frames,there is strong specular reflection on its surface and it will affect the measure result,so we proposed a new spectacle frames scanner based on multi-linear structured light which is a non-contact type and accomplished the measurement of 3D profile of the spectacle frame.The main research of this subject is as follows:(1)Designing and analyzing the scanner system of the spectacle frame after studying the technology of 3D measurement based on the structured light.Using photogrammetry based on the matrix transformation as 3D measurement model in the subject and analyzing the measurement model and principle.Finally,we deduced the formula of 3D reconstruction.(2)Design of optical system:the scanner system includes a portable projector,a 12mm prime lens and an area array color CCD camera which resolution is 1536a*1024.The projector projects binary fringes on the spectacle frame,so we can collect the image with CCD camera.By image processing and system calibration,we can get the information of the surface of the frame.According to the result of the simulation by 3ds max,we determine the optimal structure parameters of the spectacle frame scanner system,it will decrease the influence of the specular reflection and increase the experiment accuracy.It's more effective than determining it in the physical experiment.(3)3D measurement based on multi-linear structured light:this subject improved the algorithm of camera calibration based on the Zhang's calibration and proposed a new calibration algorithm for projector.By the specific design of calibration target,we can calibrate both camera and projector in a small field of view.After system calibration and 3D reconstruction,we can recover the 3D structure of the spectacle frame,and use it to make lens.(4)Software design of image collection and calibration toolbox:the image collection software can make image collection automatic to improve experiment efficiency.We can adjust the time of exposure and white balance automatically or manually,in order to get the image in best quality for further processing.The calibration toolbox can calibrate the inner and outer parameters of the camera and projector,analyze the error of image corner detection and optimize the precision of it.