基于辅助相机的景深拓展三维重建技术研究  

Research on 3D reconstruction technology of extended depth of field based on auxiliary camera

作　　者：李铁军[1,2] 薛路明 刘今越 贾晓辉[1] Li Tiejun;Xue Luming;Liu Jinyue;Jia Xiaohui(School of Mechanical Engineering,Hebei University of Technology,Tianjin 300401,China;School of Mechanical Engineering,Hebei University of Science and Technology,Shijiazhuang 050018,China)

机构地区：[1]河北工业大学机械工程学院,天津300401 [2]河北科技大学机械工程学院,河北石家庄050018

出　　处：《红外与激光工程》2023年第4期193-201,共9页Infrared and Laser Engineering

基　　金：国家重点研发计划(2019YFB1312103);国家自然科学基金(U20A20283)。

摘　　要：针对面结构光三维重建中,由于重建景深的限制导致待测物在超出重建景深后出现重建错误的问题,提出了一种基于辅助相机的景深拓展三维重建技术,并借助相位阈值自适应地对重建景深内外物体进行重建。采用四步相移与互补格雷码结合的方法获取绝对相位,通过多项式拟合法对相机、投影仪进行标定。提出了借助辅助相机建立超出重建景深的相位-高度映射的方法。实验结果表明:该方法能提高重建景深范围50%左右,大大提升了面结构光的重建范围。Objective In the three-dimensional reconstruction of surface structured light,due to the limitation of the reconstruction depth of field,the problem of reconstruction error occurs when the measured object exceeds the reconstruction depth of field.In the large scene where the longitudinal shooting range is required,a single shot cannot meet the reconstruction requirements.It is necessary to move the structured light system along the longitudinal direction and re-calibrate,which increases the complexity and repeatability of the task.In this paper,a depth-of-field extended 3D reconstruction technology based on auxiliary camera is proposed,and the objects inside and outside the reconstructed depth of field are reconstructed adaptively with the help of phase threshold.Methods The absolute phase is obtained by the combination of four-step phase shift and complementary gray code,and the camera and projector are calibrated by polynomial fitting method.With the help of the depth of field calculation model,the depth of field range of the main camera and the auxiliary camera is calculated and the device is fixed according to the specific position(Fig.2).The auxiliary camera is used to obtain the pixel coordinates of the calibration plate beyond the depth of field reconstructed by the main camera.The joint calibration results of the binocular camera are used to convert it into the main camera coordinate system.Combined with the phase value obtained by the main camera,the phase-height mapping relationship beyond the depth of field reconstructed by the main camera is established(Fig.4).Based on the traditional phase method model,the relationship between phase and shooting distance is quantitatively analyzed,and the phase adaptive threshold is proposed.Results and Discussions Three-dimensional reconstruction is carried out by using different mapping relationships for four different objects to be measured(Fig.7).The effect pictures of the traditional method(Fig.7(d))and the method in this paper(Fig.7(e))are shown respectively,an

关 键 词：面结构光 景深拓展 三维重建 相位阈值 

分 类 号：TN247[电子电信—物理电子学]