Application Research Of Three-dimentional Imaging System Based On Structured Light To Scan Ear Mold

With the rapid development of electronic technology and computer technology,in the field of additive manufacturing,machine vision and virtual reality,the demand for3 d scanning imaging technology is increasing.In the application of three-dimensional scanning in the department of otology,the extraction of the ear canal model has become the key for hearing AIDS,music headphones and various ear applications.In the past,people often take the mold by hand,the process of taking the mold is slow and the precision is low,which seriously restricts the application of ear mold technology.As one of the key techniques in 3d imaging,phase profilometry has been widely studied by many scholars,including Fourier transform profilometry and phase shift.The former only needs one modulated raster image to complete phase extraction,but due to its low accuracy,it is limited by the demand of small volume and high precision ear mode extraction.Which is effective to solve the above questions,it through multiple image related grating projection,using trigonometric function guidance formula to solve the influence of background light intensity,improve the anti-interference ability and the precision of the extraction phase of noise,but for the projector and camera and achieve high accuracy requirement is slow,so how to study the structure of high precision,non-contact optical projection 3 d scanning system to effectively extract the ear canal model,to solve the problems in the traditional molds are artificial modulus,become a research focus in this paper.This paper on the structured light projection of three-dimensional contour scanning system structure,principle and composition of summarized,and the algorithm of phase profilometry is analyzed,on the basis of based on phase shift method,in view of the ear canal model characteristics such as small volume,complex surface topography,design the structure of a high precision,high speed light projection3 d imaging system.The main work of this paper is as follows:(1)In this paper,the camera coordinate system to the world coordinate system and the camera distortion correction are completed by using the calibration algorithm.In the intersecting axis imaging system,when the image taken by the camera contains local shadow,the path tracking method is adopted to solve the influence of shadow andnoise on the correct phase demodulation.Compared with the multi-device imaging and modulation measurement,the performance of profilometry in avoiding shadow is improved significantly.(2)For modeling complex surface,molds are high precision shape surface reconstruction is not standard and the change of the light field,this paper designed a set of new 3 d imaging system,which USES digital micromirror DLP4500 reducing the loss of light intensity grating projection,by the phase shift method to reduce environmental noise impact,and call the Gdeisat airspace properly package solution algorithm to extract the molds are the initial phase.The experimental results show that the phase extraction of Gdeisat is better than that of the line-by-column method and the branch-cutting method,and the reconstruction precision of the system is higher.Finally,through the experimental results show that,compared with the Fourier transform method of contour system,this paper designed the system can complete the ear model of high precision,fast reconstruction,the height of the molds are three-dimensional morphology reconstruction after system research has some reference value,for the future of biomedical imaging provides certain ideas and methods.