共查询到18条相似文献，搜索用时 375 毫秒
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三维运动分析中定标问题的简化模型 总被引：2，自引：2，他引：0
在三维运动分析中,从分析直接线性变换算法(DLT模型)对单摄像机和双摄像机的标定方程出发,利用坐标转换方法得出一种简单适用的简化模型,为解决实践中快速确定三维运动空间坐标问题提供理论分析依据。 相似文献
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摄影框架是将运动技术的图像二维坐标向三维空间坐标转化的重要工具。采用文献资料法、走访法、实验法、数理统计法对运动图像三维解析系统的框架进行了设计、标定与数据的检验,研究结果表明摄影框架及三维解析系统精度都比较高;该文还对框架的实际应用从基本原理上作了简要介绍。目前国内对摄影框架的研究比较匮乏,该文提供了一个基本研究思路。 相似文献
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三维影像分析是运动生物力学的重要研究手段之一,广泛地应用于运动技术分析和诊断中.三维跟踪扫描影像分析方法就是摄像机跟踪运动目标来记录运动的图像,并通过专门的图像解析系统解算得到运动目标空间实际三维坐标的方法.应用SIMI Motion的Pan/Tilt/Zoom功能来实现三维跟踪扫描录像分析,并对所得到的三维测量数据的精度进行评价和分析.研究结果表明,在相同的坐标参考系下,由全站仪和影像分析测量得到的24个点的三维空间绝对坐标的平均相差值为0.018±0.003 m,三维跟踪扫描影像测量的相对误差可以达到1.97%,这样的测量精度可满足运动技术分析的要求.介绍了实现三维跟踪扫描影像分析的全过程,对影响测量精度的因素进行了初步的分析,并提出了应采取的相应措施. 相似文献
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直接线性变换(DLT)算法是利用平面图像进行三维重构的基本算法,本文从框架位置的角度对三维重构的影响进行讨论,由此得出各个框架位置下控制点的平均相对误差,结果表明框架位置对三维重构具有一定的影响,同时相机角度对三雏重构具有深远的意义。 相似文献
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D.L.T法是一种能够拍摄并解析在三维空间内运动幅度很大的技术动作的摄影技术。用两台摄影机从不同角度进行拍摄,根据两台摄影机拍摄的底片的二维坐标求出拍摄对象的三维空间坐标。这种线性变换是根据对标定框架摄影,然后求出摄影机系数来实现的。标定框架上至少有六个已知坐标的点,运用最小二乘法可得到十一元一次方程组,对其求解得到十一个摄影机系数,之后再求出点的三维坐标。 相似文献
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水下三维物空间坐标的重构精度分析 总被引：1，自引：0，他引：1
目的:水下运动学数据的精度对于游泳项目的技术动作分析十分重要,利用防水摄像装置对标定框架上的有效点在水下和空气中进行三维重构,旨在验证不同测试环境和不同大小的标定空间对水下三维重构精度的影响,为水下游泳的器材研发提供一定的参考和依据。方法:2台水下摄像机同步拍摄放置在泳池里的标定框架(2 m×2 m×1 m),标定框架采取2种不同大小的标定空间,分别对同样数目的控制点(12个)和有效点(4个)分别在水下和空气中进行三维重构,重构精度通过4个有效点的均方根(RMS)重构误差来表示,利用DLT算法和ARIEL软件进行标定重构和数字化。结果发现,在整体标定空间控制点的RMS重构误差在X、Y、Z轴上为:(ⅰ)5.60 mm、10.44 mm和3.74 mm(水下),(ⅱ)4.89 mm、4.89 mm和3.96 mm(空气);局部标定空间为(ⅰ)5.29 mm、9.18 mm和3.02 mm(水下)(ⅱ)1.44 mm、1.11 mm和3.25 mm(空气)。结论:由于光线折射不论标定空间的大小,水下三维重构所得到的RMS重构误差都高于空气中的测量,Y轴最为明显;随着标定空间的增大,两种测试环境下的RMS重构误差均随之增大。 相似文献
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对此前有关影像测量误差的研究成果和结论进行总结,认为影像测量误差的主要来源为人因误差、环境误差和装置误差等几个方面,并可分为系统误差和随机误差两类。另外,对确定影像测量精度的方法进行归纳总结,主要可分为理论分析法和实验测试法。还对减小影像测量误差的方法进行归纳,消除系统误差的主要方法有:粘贴皮肤标志点法、设置参照点法、周期运动对侧关节点计算法、局部拍摄法以及同步多框架分析标定技术等;消除随机误差的主要方法是对原始数据的平滑。 相似文献
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在人体运动的分析中,提取运动信息是必须的。对于人体运动的三维分析,图像系统常常是利用二维图像作三维重构,然后根据重构数据进行运动学、动力学分析。在重构技术中DLT算法由于其众多优点而得到了广泛应用。但是,由于人的运动是复杂而精细的,三维重构误差对运动分析误差的影响成为三维分析研究的关键点。针对三维重构所引起的误差,讨论了如何通过有效的方法来减小误差,以提高三维解析数据的精度,并提出了相关的方法和措施,为编制三维解析系统时提高精度提供可靠的理论依据。 相似文献
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Young‐Hoo Kwon Jeffrey B. Casebolt 《Sports biomechanics / International Society of Biomechanics in Sports》2013,12(2):315-340
One of the most serious obstacles to accurate quantification of the underwater motion of a swimmer's body is image deformation caused by refraction. Refraction occurs at the water‐air interface plane (glass) owing to the density difference. Camera calibration‐reconstruction algorithms commonly used in aquatic research do not have the capability to correct this refraction‐induced nonlinear image deformation and produce large reconstruction errors. The aim of this paper is to provide a thorough review of: the nature of the refraction‐induced image deformation and its behaviour in underwater object‐space plane reconstruction; the intrinsic shortcomings of the Direct Linear Transformation (DLT) method in underwater motion analysis; experimental conditions that interact with refraction; and alternative algorithms and strategies that can be used to improve the calibration‐reconstruction accuracy. Although it is impossible to remove the refraction error completely in conventional camera calibration‐reconstruction methods, it is possible to improve the accuracy to some extent by manipulating experimental conditions or calibration frame characteristics. Alternative algorithms, such as the localized DLT and the double‐plane method are also available for error reduction. The ultimate solution for the refraction problem is to develop underwater camera calibration and reconstruction algorithms that have the capability to correct refraction. 相似文献
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Young‐Hoo Kwon Jeffrey B. Casebolt 《Sports biomechanics / International Society of Biomechanics in Sports》2013,12(1):95-120
One of the most serious obstacles to accurate quantification of the underwater motion of a swimmer's body is image deformation caused by refraction. Refraction occurs at the water‐air interface plane (glass) owing to the density difference. Camera calibration‐reconstruction algorithms commonly used in aquatic research do not have the capability to correct this refraction‐induced nonlinear image deformation and produce large reconstruction errors. The aim of this paper is to provide a through review of: the nature of the refraction‐induced image deformation and its behaviour in underwater object‐space plane reconstruction; the intrinsic shortcomings of the Direct Linear Transformation (DLT) method in underwater motion analysis; experimental conditions that interact with refraction; and alternative algorithms and strategies that can be used to improve the calibration‐reconstruction accuracy. Although it is impossible to remove the refraction error completely in conventional camera calibration‐reconstruction methods, it is possible to improve the accuracy to some extent by manipulating experimental conditions or calibration frame characteristics. Alternative algorithms, such as the localized DLT and the double‐plane method are also available for error reduction. The ultimate solution for the refraction problem is to develop underwater camera calibration and reconstruction algorithms that have the capability to correct refraction 相似文献
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Effects of light refraction on the accuracy of camera calibration and reconstruction in underwater motion analysis 总被引：1，自引：0，他引：1
Kwon YH Casebolt JB 《Sports biomechanics / International Society of Biomechanics in Sports》2006,5(2):315-340
One of the most serious obstacles to accurate quantification of the underwater motion of a swimmer's body is image deformation caused by refraction. Refraction occurs at the water-air interface plane (glass) owing to the density difference. Camera calibration-reconstruction algorithms commonly used in aquatic research do not have the capability to correct this refraction-induced nonlinear image deformation and produce large reconstruction errors. The aim of this paper is to provide a thorough review of: the nature of the refraction-induced image deformation and its behaviour in underwater object-space plane reconstruction; the intrinsic shortcomings of the Direct Linear Transformation (DLT) method in underwater motion analysis; experimental conditions that interact with refraction; and alternative algorithms and strategies that can be used to improve the calibration-reconstruction accuracy. Although it is impossible to remove the refraction error completely in conventional camera calibration-reconstruction methods, it is possible to improve the accuracy to some extent by manipulating experimental conditions or calibration frame characteristics. Alternative algorithms, such as the localized DLT and the double-plane method are also available for error reduction. The ultimate solution for the refraction problem is to develop underwater camera calibration and reconstruction algorithms that have the capability to correct refraction. 相似文献
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Kwon YH Casebolt JB 《Sports biomechanics / International Society of Biomechanics in Sports》2006,5(1):95-120
One of the most serious obstacles to accurate quantification of the underwater motion of a swimmer's body is image deformation caused by refraction. Refraction occurs at the water-air interface plane (glass) owing to the density difference. Camera calibration-reconstruction algorithms commonly used in aquatic research do not have the capability to correct this refraction-induced nonlinear image deformation and produce large reconstruction errors. The aim of this paper is to provide a through review of: the nature of the refraction-induced image deformation and its behaviour in underwater object-space plane reconstruction; the intrinsic shortcomings of the Direct Linear Transformation (DLT) method in underwater motion analysis; experimental conditions that interact with refraction; and alternative algorithms and strategies that can be used to improve the calibration-reconstruction accuracy. Although it is impossible to remove the refraction error completely in conventional camera calibration-reconstruction methods, it is possible to improve the accuracy to some extent by manipulating experimental conditions or calibration frame characteristics. Alternative algorithms, such as the localized DLT and the double-plane method are also available for error reduction. The ultimate solution for the refraction problem is to develop underwater camera calibration and reconstruction algorithms that have the capability to correct refraction. 相似文献
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通过DLT理论的研究，结合人体运动图像三维解析系统的开发，从理论和实际应用中所出现误差原因的分析，给出实际误差修正的方法，并进一步提出续集和建议，以供实际应用参考和其它设计人员在后继研究设计中借鉴。 相似文献
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Nathan Elliott Simon Choppin Simon Goodwill Terry Senior John Hart Tom Allen 《Sports Engineering》2018,21(2):137-147
Stereo camera systems have been used to track markers attached to a racket, allowing its position to be obtained in three-dimensional (3D) space. Typically, markers are manually selected on the image plane, but this can be time-consuming. A markerless system based on one stationary camera estimating 3D racket position data is desirable for research and play. The markerless method presented in this paper relies on a set of racket silhouette views in a common reference frame captured with a calibrated camera and a silhouette of a racket captured with a camera whose relative pose is outside the common reference frame. The aim of this paper is to provide validation of these single view fitting techniques to estimate the pose of a tennis racket. This includes the development of a calibration method to provide the relative pose of a stationary camera with respect to a racket. Mean static racket position was reconstructed to within ±2 mm. Computer generated camera poses and silhouette views of a full size racket model were used to demonstrate the potential of the method to estimate 3D racket position during a simplified serve scenario. From a camera distance of 14 m, 3D racket position was estimated providing a spatial accuracy of 1.9 ± 0.14 mm, similar to recent 3D video marker tracking studies of tennis. 相似文献
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阐述了序列运动图像采集与解析系统的系统功能和结构，详细给出了系统各功能模块的结构框图，介绍了系统的界面、有关各模块的功能与具体操作。 相似文献