Research On Binocular Vision 3D Reconstruction Technology Based On Gray Code And Phase Shift

Non-contact measurement which can be divided into natural light measurement and structured light measurement is an important method of three-dimensional reconstruction technology.Structured light measurement method has lots of advantages include lower cost,higher efficiency and accuracy,and is widely used in robot navigation,reverse engineering,medical diagnosis and other scenarios.In order to improve the accuracy of three dimensional reconstruction,a binocular vision measurement method based on Gray code-phase shift is improved,and the accurate non-contact 3D reconstruction of objects is completed.In the process of experiment,due to the different reflectivity of the object under test,the threshold segmentation can not be performed accurately.A method of projecting two sets of Gray coded patterns to the object under test is proposed.A series of gratings with sinusoidal periodic variations are projected onto the object to be measured by four-step phase-shifting method,and a new correction method is proposed to correct the periodic dislocation phenomena occurring in the absolute principal phase.Compared with the traditional correction method it has better matching effect.The main work of this paper is as follows.1.Analysis and research the binocular stereo vision system,including the imaging principle of binocular vision,the relationship and transformation of each reference coordinate system.Accurate calibration of binocular is the key to ensure the accuracy of the whole measurement system,so the focus of the study of camera calibration principle,and completed the accurate calibration of the whole measurement system.2.The commonly used structured light coding methods are analyzed and contrast.Combined with the subject of this paper,selected the gray code and phase shift coding method,for the gray code coding method,a recursive generation method is adopted.In order to decode convenience,a method of projecting positive and negative two groups of Gray coded patterns to the detected object is proposed,greatly improves the accuracy of gray code decoding.3.In order to solve the dislocation phenomena between Gray code period and phase shift period,a new periodic dislocation correction method is proposed,which isdifferent from the traditional one.And in the Measurement of bone model,the traditional periodic dislocation correction method and the new periodic dislocation correction method are used respectively,comparison of three dimensional cloud images generated by the two method,then can be clearly seen that the proposed method can achieve better reconstruction results.4.Building experiment platform of hardware and software,and experiment three dimensional reconstruction experiment for 3D printing bone model and lion head model.Firstly,the three-dimensional reconstruction of the bone model is completed,but because of the limitation of the field of view,the reconstruction of the bone model is incomplete.Therefore,the lion head model is completed by using the marker stitching measurement.Three dimensional reconstruction has achieved accurate results.