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基于相位法的三维面型测量及曲面重建技术 总被引:1,自引:0,他引:1
文中采用相位法对三维面型测量和曲面重建技术进行了探讨,实现了三维信息获取和曲面重建的方法。该方法是用非相干光源投射的虚拟光栅和 CCD 摄像机构成的视觉系统对物体进行一次扫描获取物体表面的三维测量数据,这些数据经过处理后转换成*.ibl 文件,借助于 Pro/Engineer 软件重建三维物体表面。该方法快速、简便,适合于实时测量、加工,同时可实现测量、处理、加工的一体化,从而为反求工程的发展提供了一个很好的新方法。最后给出了实验,实验结果证明了方法的可行性和有效性。 相似文献
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基于矩形光栅结构光和双目立体视觉测量技术,提出一种物体表面三维形貌的动态测量方法。采用基于光平面引导的稠密光栅光条匹配方法完成左右摄像机光条图像的匹配,该方法先通过各光平面对应的单应矩阵实现左右图像点的对应,再结合极限约束及空间点距离约束完成左右光条中心点的全局最优匹配,以此解决由两摄像机和投影仪组成光栅结构光测量系统中光条匹配难题,对匹配完成的图像光条点应用双目立体视觉测量原理完成物体表面的三维重建。实物实验中,对姿态变化的手臂进行测量,结果证明仅需投影单幅光栅图案可实现手臂三维形貌的测量,验证该方法的有效性。 相似文献
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利用从运动中恢复结构方法(SFM),提出了一种基于多视图立体视觉的沙堆三维重建及三维尺寸测量方法。首先根据SFM方法的求解不稳定特点,结合光束平差法对SFM求解过程进行分析及优化;其次针对SFM重建结果为稀疏点云的问题,利用基于面片的稠密重建算法重新生成稠密的三维点云,再利用泊松算法对密集点云进行三维曲面重建;最后获得模型的三维尺寸信息。对某建筑工地的沙堆进行了三维尺寸的测量实验,实验结果验证了该方法的有效及可行性,提高了重建能力及精度,同时考虑了目标实际测量误差与重建误差,能够满足实际智能测量的应用需求。 相似文献
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用改变表面位置的方法设计平行面立体和垂直面立体的视图,它是基于压缩坐标形成视图的原理,先设定一个视图,在该视图上拟出可见面和 不可见面,在另外两个视图上确定各表面的位置,连接各表面的端点重影点,可以设计出立体的另外两个视图,交叉改变各表面的位置,就可以设计出多种形状各不相同的立体的视图,应用此法不仅可设计平面立体的视图,并可设计曲面立体的视图。 相似文献
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《振动与冲击》2015,(16)
针对高速冲击荷载作用后泡沫铝夹层板表观变形测量需要,研究基于立体视觉的表观变形三维测量方法。选择去均值归一化灰度互相关系数(NCCC)进行区域匹配,通过调整视差范围消除虚假误差,以实现最大最小视差约束;并综合使用5种约束优化视差图。据平行双目立体视觉模型计算三维点云坐标,用Delaunay三角剖分获得表观变形曲面。基于MATLAB平台集成表观变形立体视觉三维测量系统,进行距离测量精度及比较试验证明该方法的有效性及可靠性。用集成系统完成高速冲击荷载作用后泡沫铝夹层板表观变形的三维测量试验。结果表明,重建的三维曲面能准确再现高速冲击荷载作用后泡沫铝夹层板的表观变形,为高速冲击荷载作用后靶标表观变形提供全新的测量方法。 相似文献
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双目立体视觉是计算机视觉的一个重要分支,即由构成一定角度的两台摄象机拍摄同一幅画面,通过计算空间点在两幅图像中的视差,获得该点的三维坐标值.提出将双目立体计算机视觉技术应用于光学立体显微镜上,可对一些微小物体进行观测和测量,并获取深度信息,建立三维图象,从而用简便、经济的手段进行微小物体的三坐标测量. 相似文献
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基于LS-SVM的立体视觉摄像机标定 总被引:2,自引:1,他引:1
利用最小二乘支持向量机来直接学习图像信息与三维信息之间的关系,不需确定摄像机具体的内部参数和外部参数.在双目视觉的情况下,两摄像机的位置关系不需具体求出,而是隐含在映射关系中.根据最小二乘支持向量机与摄像机标定的特点,提出了基于最小二乘支持向量机的双目立体摄像机标定方法.将摄像头采集到的图像的像素坐标作为输入,将世界坐标作为输出,用最小二乘支持向量机使网络实现给定的输入输出映射关系.该方法同BP神经网络预测结果对比表明:基于最小二乘支持向量机的双目视觉标定方法速度快,实时性好,能有效提高标定精度. 相似文献
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Abstract In this paper, two methods, the Individual Calibration Method (ICM) and the Simultaneous Calibration Method (SCM), are used to calibrate a vision system with two cameras. The first approach calibrates a camera individually. For the second approach, two or more sets of camera intrinsic and extrinsic parameters are determined simultaneously such that the position errors for the 3‐D points are minimized. We show, theoretically and experimentally, the following results: (a) the offsets of the image centers do not affect significantly the position and orientation of a coordinate frame with respect to a stereo vision system with two cameras; (b) the lens distortion will not change dramatically the position and orientation of a coordinate frame with respect to a stereo vision system. We also find that (a) there is a difference in the determination of an object's location for the simultaneous and individual calibration methods; (b) the approach of calibrating two cameras simultaneously has the advantage of better accuracy over the method of individual calibration. 相似文献
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Data input model for virtual reality-aided facility layout 总被引:2,自引:0,他引:2
An approach to automatically extract three dimensional (3D) models (that is, geometries and topologies) of physical objects in a facility is described. The rationale for this work is its repeated use in efficiently developing databases of 3D objects for applying virtual reality (VR) tools in detailed layout decision support. Obtaining 3D object models can be a challenging task. Sometimes they are available, for example, in a Computer-Aided Design (CAD) database and these can be readily imported into a VR database. But on many occasions one is not so fortunate and these object models have to be created in correlation to an existing or proposed facility, which can be an extremely tedious and time consuming task. A time efficient and economical alternative is to use video camera images, but quickly and accurately capturing the depth information from 2D camera images has so far remained elusive because the existing methodologies are too general purpose and operate at a lower level of abstraction, namely digitized images. We have developed a method for directly inputting 3D objects into VR-aided facility layout models, by integrating the strengths of previously tried and tested technological components: (i) camera calibration; (ii) image processing; (iii) stereo vision; and (iv) Delaunay triangulation. The techniques described here are embedded in a prototype architecture and toolkit called MIRRORS (Methodology for Inputting Raw Recordings into 3D Object Renderings for Stereo). The primary contribution of this paper is that it has been able to design an integrated system to build 3D object models from 2D images. The MIRRORS system has been primarily designed for objects without free-form surfaces and whose shape can be recovered from a relatively nondense set of points. 相似文献
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Stereoscopic imaging and computer vision of impinging fires by a single camera with a stereo adapter
In this article, the novelty of using a single camera for stereoscopic imaging and computer vision of fire dynamics has been described. Specifically, 3D surface topology of the fires can be reconstructed and visualized using stereoscopic methodology. The basic stereo apparatus used in the present study consists of a high‐resolution digital camera and a stereo adapter, which is mounted to the front filter ring of the camera. A pair of stereo images could therefore be formed through the same lens system and recorded simultaneously on the same charge coupled device (CCD) chip. The mechanism of using a stereo adapter for stereoscopic imaging and its geometry has been elaborated in detail. The digitally reconstructed 3D results have also been validated by optical stereoscopic viewing using a pair of electronic shutter glasses synchronized with a computer monitor. The results have demonstrated that the single camera technique is a very powerful and cost‐effective diagnostic tool for fire studies. © 2005 Wiley Periodicals, Inc. Int J Imaging Syst Technol, 15, 114–122, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ima.20044 相似文献
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Xiao-feng Feng 《Journal of Modern Optics》2013,60(15):1204-1210
A single camera stereo vision sensor model based on planar mirror imaging is proposed for measuring a three-dimensional point. The model consists of a CCD camera and a planar mirror. Using planar mirror reflections of a scene, a picture with parallax is obtained by shooting the target object and its virtual image. This is equivalent to shooting the target object from different angles with the camera and the virtual camera in the planar mirror, so it has the function of binocular stereo vision. In addition, the measurement theory of the three-dimensional point is discussed. The mathematical model of a single camera stereo vision sensor is established, the intrinsic and extrinsic parameters are calibrated, and the corresponding experiment has been done. The experimental results show that the measuring method is convenient and effective; it also has the advantages of simple structure, convenient adjustment, and is especially suitable for short-distance measurement with high precision. 相似文献
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双目视觉摄像机神经网络标定方法 总被引:9,自引:0,他引:9
摄像机标定是精密视觉测量的基础。为了描述双目视觉中三维空间物点坐标和两个摄像机像面像点坐标间的非线性关系,传统的标定方法需要建立复杂的数学模型。而神经网络可以有效地处理非线性映射问题,笔者介绍了一种BP(ErrorBackPropagation)神经网络,并且为了提高网络的学习能力引入了动态因子。用相同的参考数据,将神经网络标定方法与线性标定方法比较,实验结果表明基于神经网络的双目视觉标定方法能获得较高的标定精度。 相似文献
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《成像科学杂志》2013,61(8):440-446
In this paper, we present a descent image based extraterrestrial terrain reconstruction technology, which has been successfully applied in China's first soft landing Chang'E-3 mission on moon. When scouting on the moon surface, the lunar rover (Jade Rabbit rover) requires reliable terrain information for navigation and positioning tasks. The descent image sequence acts as a link between the orbital images and the surface images. The proposed approach collects multilevel descent images, as well as inertial information from an inertial measurement unit and surface stereo vision information, to generalise a consistent surface model. A data fusion strategy is proposed to track the camera trajectory, and refined plane sweep stereo matching and 3D alignment technologies are analysed in this article. The onboard result, as well as on-earth simulation experiments, has shown that the discussed techniques are reliable to reconstruct the terrain information for the lunar rover's localisation and navigation. 相似文献
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Stereo calibration of binocular ultra-wide angle long-wave infrared camera based on an equivalent small field of view camera 总被引:1,自引:0,他引:1
ABSTRACTIn this paper, a stereo calibration method for binocular ultra-wide angle long-wave infrared camera is proposed on the basis of an equivalent small field of view camera. Extrinsic parameters are calibrated through the corrected images from the left and right cameras. They can be viewed as images taken by a small field of view camera. The calibration procedure consists of three steps: monocular calibration, distortion correction and extrinsic parameters calibration. In order to evaluate the accuracy of the method, stereo vision of the camera is modelled and a 3D reconstruction approach is presented. A series of experiments, including intrinsic parameters, extrinsic parameters and 3D reconstruction, are conducted to validate the proposed method. The results show that the baseline length error decreases to 0.67%, and the relative error for the 3D reconstruction of corners is smaller than 8.11%. In contrast to the common stereo calibration method, it improves calibration accuracy. 相似文献
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Abstract: We present a new method that combines the fringe projection and the digital image correlation (DIC) techniques on a single hardware platform to simultaneously measure both shape and deformation fields of three‐dimensional (3‐D) surfaces with complex geometries. The method in its basic form requires only a single camera and single projector, but this can be easily extended to a multi‐camera multi‐projector system to obtain complete 360° measurements. Multiple views of the surface profile and displacement field are automatically co‐registered in a unified global coordinate system, thereby avoiding the significant errors that can arise through the use of statistical point cloud stitching techniques. Experimental results from a two‐camera two‐projector sensor are presented and compared with results from both a standard stereo‐DIC approach and a finite element model. 相似文献