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双目定位跟踪系统涉及到的关键技术有摄像机标定、立体匹配和三维重建等.在三维重建阶段,利用匹配的结果采用最小二乘法计算定位标靶上标记的三维坐标.实验结果表明,在现有条件下,双目定位跟踪系统的定位精度比较高,相对误差在1%以内;基于此定位跟踪系统,能够初步准确完成对经络的三维定位和实时显示,为临床诊断治疗和基础教学提供直观的分析依据. 相似文献
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INTRODUCTION Pose and structural parameters analysis of 2Dimages sets find application in many areas such asobject recognition, motion estimation, navigationplanning, and structural analysis of 3D objects(Huang and Netravali, 1994), image communica-tion, and image coding (Mitiche and Aggarwal,1986). Normally, given one set of 3D object pointdata and their corresponding 2D projective imagepoint data, the 3D-2D calibration problem is re-ferred to as the estimation of the camera par… 相似文献
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Pose and structure estimation from a single image is a fundamental problem in machine vision and multiple sensor fusion and integration.In this paper we propose using rigid constraints described in different coordinate frames to iteratively estimate structural and camera pose parameters.Using geometric properties of reflected correspondences we put forward a new concept,the reflected pole of a rigid transformation.The reflected pole represents a general analysis of transformations that can be applied to both 2D and 3D transformations.We demonstrate how the concept is applied to calibration by proposing an iterative method to estimate the structural parameters of objects.The method is based on a coarse-to-fine strategy in which initial estimation is obtained through a classical linear algorithm which is then refined by iteration.For a comparative study of performance,we also implemented an extended motion estimation algorithm(from 2D-2D to 3D-2D case)based on epipolar geometry. 相似文献
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INTRODUCTION Stereo rectification is a crucial processing forany practical stereovision system; and is aimedtransform images so that the conjugate epipolarlines are aligned horizontally and in parallel. Variedand numerous rectification algorithms have beengiven in literature (Ayache and Lustman, 1991;Fusiello et al., 2000; Hartley, 1999; Robert et al.,1995; Mulligan and Kaniilidis, 2000; Isgro andTrucco, 1999). Most of them involve applying ahomography transformation for that purpose. … 相似文献
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The linear multi-baseline stereo system introduced by the CMU-RI group has been proven to be a very effective and robust stereovision system. However, most traditional stereo rectification algorithms are all designed for binocular stereovision system, and so, cannot be applied to a linear multi-baseline system. This paper presents a simple and intuitional method that can simultaneously rectify all the cameras in a linear multi-baseline system. Instead of using the general 8-parameter homography transform, a two-step virtual rotation method is applied for rectification, which results in a more specific transform that has only 3 parameters, and more stability. Experimental results for real stereo images showed the presented method is efficient. 相似文献
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A method was presented to implement the detecting and tracking of moving targets through omnidirectional vision. The method
combined optical flow with particle filter arithmetic, in which optical flow field was used to detect and locate moving targets
and particle filter was used to track the detected moving objects. According to the circular image character of omnidirectional
vision, the calculation equation of optical flow field and the tracking arithmetic of particle filter were improved based
on the polar coordinates at the omnidirectional center. The edge of a randomly moving object could be detected by optical
flow field and was surrounded by a reference region in the particle filter. A dynamic motion model was established to predict
particle state. Histograms were used as the features in the reference region and candidate regions. The mutual information
(MI) and Gaussian function were combined to calculate particle weights. Finally, the state of tracked object was computed
by the total particle states with weights. Experiment results show that the proposed method could detect and track moving
objects with better real-time performance and accuracy.
Supported by Tianjin Higher Education Technology Development Foundation (No.20071308), Tianjin Natural Science Foundation
(06YFJMJC03600) and National Natural Science Foundation of China (No.60773073).
YANG Shuying, born in 1964, female, Dr, Prof. 相似文献
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Bruce Wainman Giancarlo Pukas Liliana Wolak Sylvia Mohanraj Jason Lamb Geoffrey R. Norman 《Anatomical sciences education》2020,13(3):401-412
Anatomy education has been revolutionized through digital media, resulting in major advances in realism, portability, scalability, and user satisfaction. However, while such approaches may well be more portable, realistic, or satisfying than traditional photographic presentations, it is less clear that they have any superiority in terms of student learning. In this study, it was hypothesized that virtual and mixed reality presentations of pelvic anatomy will have an advantage over two-dimensional (2D) presentations and perform approximately equal to physical models and that this advantage over 2D presentations will be reduced when stereopsis is decreased by covering the non-dominant eye. Groups of 20 undergraduate students learned pelvic anatomy under seven conditions: physical model with and without stereo vision, mixed reality with and without stereo vision, virtual reality with and without stereo vision, and key views on a computer monitor. All were tested with a cadaveric pelvis and a 15-item, short-answer recognition test. Compared to the key views, the physical model had a 70% increase in accuracy in structure identification; the virtual reality a 25% increase, and the mixed reality a non-significant 2.5% change. Blocking stereopsis reduced performance on the physical model by 15%, on virtual reality by 60%, but by only 2.5% on the mixed reality technology. The data show that virtual and mixed reality technologies tested are inferior to physical models and that true stereopsis is critical in learning anatomy. 相似文献
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This paper presents a pure vision based technique for 3D reconstruction of planet terrain. The reconstruction accuracy depends ultimately on an optimization technique known as ＇bundle adjustment＇. In vision techniques, the translation is only known up to a scale factor, and a single scale factor is assumed for the whole sequence of images if only one camera is used. If an extra camera is available, stereo vision based reconstruction can be obtained by binocular views. If the baseline of the stereo setup is known, the scale factor problem is solved. We found that direct application of classical bundle adjustment on the constraints inherent between the binocular views has not been tested. Our method incorporated this constraint into the conventional bundle adjustment method. This special binocular bundle adjustment has been performed on image sequences similar to planet terrain circumstances. Experimental results show that our special method enhances not only the localization accuracy, but also the terrain mapping quality. 相似文献
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针对智能停车库中的泊车机器人视觉系统研究需求,提出一种基于双目视觉的泊车机器人障碍物识别系统。通过双目摄像头进行图像采集,利用张正友棋盘标定法进行双目相机标定;采用Bouguet进行立体校正,将高斯滤波与拉普拉斯算子相结合进行图像预处理;采用YOLO卷积神经网络对目标障碍物进行快速识别;利用区域匹配算法进行立体匹配并生成目标障碍物视差图;通过成像点和目标障碍物的立体几何关系计算得到目标障碍物的深度信息。实验结果表明,该系统具有良好的实时性和较高精度,障碍物识别时间平均为0.0901s,在2 600mm具有最佳测距精度,可为泊车机器人自动泊车提供保障。 相似文献
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A simple method for calculating the 3D coordinates of points on a moro object in a multi-camera system is proposed.It simplifies the algorithms used in traditional computer vision system by eliminating the calculation of the CCD( charge coupled device) camera parameters and the relative position between cameras,and using solid geometry in the calculation procedres instead of the calculation of the complex matrixes,The algorithm was used in the research of generating a virtual magnified 3D image of a micro object to be operated in a micro operation system,and the satisfactory results were obtained.The application in a virtual tele-operation system for a dexterous mechanical gripper is under test. 相似文献
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在交通标志实时识别时,由于参考图像与实测图像非同时获取,摄像机与被摄交通标志之间的位置难以保证完全相同,致使所获取的交通标志参考图像与实测图像之间可能产生几何失真。几何失真对交通标志图像的识别结果有较大影响,因此寻找一种具有旋转和比例不变性的图像识别方法势在必行。基于不变矩的交通标志识别算法,首先对交通标志图像进行归一化处理,然后求其Hu矩,最后利用相关性测度算法进行比较。结果表明,算法针对旋转或缩放后的交通标志图像具有100%的识别率。 相似文献
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Tracking multiple people under occlusion and across cameras is a challenging question for discussion. Furthermore, the cameras in this study are used to extend the field of view, which are distinguished from the same field of view. Such corre-spondence between multiple cameras is a burgeoning research subject in the area of computer vision. This paper effectively solves the problems of tracking multiple people who pass from one camera to another and segmenting people under occlusion using probabilistic models. The probabilistic models are composed ofblob model, motion model and color model, which make the most of the space, motion and color information. First, we present a color model that uses maximum likelihood estimation based on non-parametric kernel density estimation. Second, we introduce a blob model based on mean shift, which segments the body into many regions according to the color of each person in order to spatially localize the color features corresponding to the way people are dressed. Clothes can be any mixture of colors. Third, we bring forward a motion model based on statistical probability which indicates the movement position of the same person between two successive frames in a single camera. Finally, we effectively unify the three models into a general probabilistic model and attain a maximization likelihood probability image, which is used to segment the foreground region under occlusion and to match people across multiple cameras. 相似文献
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为了满足现代工业生产中精度要求高、操作快捷的要求,提出基于单目视觉的单图标定算法。通过采集一张棋盘格标定板图像,精确提取棋盘格角点坐标,使用仿射变换得到像素坐标系和世界坐标系的仿射变换矩阵,分析Halcon仿射变换矩阵和张氏标定法相机模型的对应关系,得到详细的相机内参,再对图像进行畸变矫正,得到像素当量。多次Halcon实验结果表明,提出的算法与其他方法相比,操作更加快捷,标定结果标准差可控制在0.02 mm 以内,能够满足现代工业生产需要。 相似文献
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讨论了基于几何和基于图象的虚拟环境建模技术,并以此开发出一个虚拟环境的建模系统.系统以OpenGL和Visual C 6.0为开发平台,可方便的进行虚拟场景的建模,并具有光照、纹理映射等真实感增强处理方法.建立的虚拟场景立体视觉效果明显,且兼顾了场景的实时性和可交互性. 相似文献
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Computer vision has very wide application in human motion capture research. This paper proposes a new approach to do motion
capture in video. It is composed of image sequence based tracking of human feature points and the reconstruction of the three-dimension(3D)
motion skeleton. First, every part of the human body from top to bottom is tracked on the basis of a human model. The image
difference and a morph-block similarity algorithm based on subpixels are used. Then camera calibration is done using the line
correspondences between the 3D model and the image. Finally the 3D motion skeleton is established by use of the model knowledge.
This approach does not aim at a given mode of human motion. Rather, it analyzes large scale motion from frame to frame in
complex, variational background, and sets up a 3D motion skeleton in the perspective projection. The experiment results are
presented at the end of the paper.
Project (69803009) supported by Natural Science Foundation of China (NSFC) and Key Project of National Development Planning
Committee. 相似文献
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理科教育对于培养军事高科技人才具有举足轻重的地位,理科实践教学作为培养学生创新能力的重要环节,是高质量理科教育体系的重要组成部分。本文在全面分析国内外著名军事院校理科实践教学现状的基础上,针对理科学科特点和当前存在的主要问题,提出了军队院校理科实践教学的基本思路,即从观念转变、课程设置、案例建设、评价体系几个方面构建立体化实践教学体系,培养高科技新型军事人才。 相似文献
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Depth estimation is an active research area with the developing of stereo vision in recent years. It is one of the key technologies
to resolve the large data of stereo vision communication. Now depth estimation still has some problems, such as occlusion,
fuzzy edge, real-time processing, etc. Many algorithms have been proposed base on software, however the performance of the computer configurations limits the software
processing speed. The other resolution is hardware design and the great developments of the digital signal processor (DSP),
and application specific integrated circuit (ASIC) and field programmable gate array (FPGA) provide the opportunity of flexible
applications. In this work, by analyzing the procedures of depth estimation, the proper algorithms which can be used in hardware
design to execute real-time depth estimation are proposed. The different methods of calibration, matching and post-processing
are analyzed based on the hardware design requirements. At last some tests for the algorithm have been analyzed. The results
show that the algorithms proposed for hardware design can provide credited depth map for further view synthesis and are suitable
for hardware design. 相似文献
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车辆 A 柱盲区和侧方盲区常常会给行车过程带来巨大安全隐患,而现有盲区解决方案大多以第三视角合成显示,因畸变过大及视角过小等原因难以在行车过程中使用。利用摄像头及相关图像处理方法,对车辆盲区部分以第一视角进行重现显示。首先在车辆外部安装一组摄像头,然后利用标定板得到相机内参,之后基于参数计算求得透视变换矩阵,对采集到的图像根据驾驶员视角作透视变换处理,最后利用全景合成算法拼接成一副全景图,借助显示设备将一幅没有盲区的画面实时显示给驾驶员。实验结果表明,该方法能有效消除车辆 A 柱及侧方盲区,适合在行车过程中使用,且处理速度满足实时性要求。 相似文献