Research On The Body Measurement Based On Three Dimensional Reconstruction

In accordance with the definition of body dimensions, body measurement means thatbody external characteristics data is obtained by some technical means. It includes themeasurement of straight lines, arcs, angles of various parts of the human body. It has animportant significance in the field of medicine, population health research, industrial design,human simulation, tailoring and so on. The3D reconstruction is a technology which is viaanalyzing the gray information of one or more images, and combined with some priorknowledge, to obtain the3D surface shape of objects. With the development of computertechnology, photovoltaic technology, machine vision and other disciplines, the3Dreconstruction technology has gone through several decades, and it has undergone a fullychange from contact type to non-contact type, and manual work to computer automation. Atpresent, the body measurement has two ways, manual measurement and automaticmeasurement. The automatic measurement mainly has photographic method and3Dreconstruction method. The3D reconstruction method firstly reconstructs the3D model of thehuman body, and then it measures body dimensions through this3D model. Therefore,automatic measurement will be better than the manual measurement, and it will be morecomprehensive, convenient, fast, and the obtained digital information will be easier to save,analysis and research. Meanwhile, the technology, there is still much space for development.The method for obtaining3D models of human body mainly includes laser scanningmethod,3D imaging method, computer tomography technology and structured lighttechnology. According to the principle of triangulation, the3D reconstruction method basedon structured light has used encoded structured light stripe pattern which is projected by theprojector to the human body, then it decodes the pattern and reconstructs the human3D pointcloud data, meanwhile, according to the characteristics of the human body, it can obtain thealgorithm. Therefore, through the3D point cloud data, body measurement can be achieved.This method is accurate, low cost, less restrictions on the measurement environment and thematerial of object to be measured.The paper includes the following aspects:(1) Based on the analysis of the principle and mathematical model of the3Dreconstruction technology, the transformation formula between the world coordinate systemand the image coordinate system has been researched, and it elaborated encoding anddecoding method of3D reconstruction based on Gray code structured light. Besides, itanalyzed parameters of the3D reconstruction system and achieved3D reconstruction of themannequins;(2) It researched on the calibration method of the system, and it has achieved cameracalibration method based on radially arranged constraint calibration. Besides, according to theprinciple of optical path reversible, it calibrated the projector. (3) According to the definition of characteristics of human body and division of the limb,it designed an algorithm which could extract body dimensions. Meanwhile, through thehuman3D point cloud data, it implemented the measurement of the basic human bodydimensions, such as height, bust, waist, and hips.