共查询到18条相似文献,搜索用时 203 毫秒
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提出了基于圆心共线约束的鱼眼镜头径向畸变估计方法。拍摄单幅至少包含空间二组平行直线的标定图像。在单参数除法径向畸变模型下,空间平行直线被映射为畸变图像上的一组圆弧。通过推导发现由同一组平行直线投影得到的圆弧会相交于二个公共交点,因而它们的圆心具有共线性质。在拟合圆弧参数时利用圆心共线性质,能够达到精确求解的目的。提出了基于圆心共线圆弧的单参数除法模型参数的求解方法,并进一步提出了圆心共线圆弧的非线性优化拟合方法。仿真和真实图像的实验结果都表明,相比传统方法,所提出的方法鲁棒性强,能有效提高标定的精度。 相似文献
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全景视觉是计算机视觉领域中的关键技术之一,而投影模型在全景技术中又起到了非常重要的作用。为了减少柱面投影带来的水平直线畸变以及保证不同摄像机之间图像接合处的平滑性,本文针对多摄像机全景系统提出了基于柱面的多平面全景投影技术,该技术首先通过对每个摄像机图像平面做柱面投影来实现柱面全景图像。然后在根据柱面全景中的内容进行水平二次划分为几个子图像。最后,对划分后的子图像再按照反柱面投影模型进行一次多平面投影就得到水平直线畸变较小的全景图像。实验结果表明该方法校正后的全景图像中水平直线的曲率不大于0.002,同时还保证了不同图像平面接合处的平滑性。 相似文献
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光栅投影式三维摄影测量仪的几何标定方法 总被引:1,自引:0,他引:1
光栅投影式三维摄影测量仪利用了时域结构光投影技术和立体视觉测量原理获得三维点坐标。针对传统标定方法易受镜头畸变影响和标定约束方程少导致精度下降的问题,采用了非线性的摄像机和投影机模型,并提出了二维的投影机模型;使用多平面法标定了系统测量所需的摄像机和投影机几何参数;为进一步提高参数精度,采用Levenberg-Marquardt算法优化了摄像机和投影机模型。实验结果表明,该方法操作简单,无需精确的位置和姿态调整,标定的绝对精度为0.2pixel,相对精度为1/5000。 相似文献
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标定十字结构光传感器的新方法 总被引:1,自引:0,他引:1
建立了基于十字结构光的视觉传感器的数学模型,提出了一种基于自由移动平面靶标的十字结构光传感器参数的简易标定方法。在自由移动的平面靶标上建立局部世界坐标系,将通过交比不变方法获得的两个光平面上特征点的局部世界坐标,变换到摄像机坐标系,从而获得已知三维的标定特征点。利用构建的分别位于两个光平面上标定特征点,可以实现工作状态的十字结构光传感器参数的优化估计。该标定方法降低了标定设备的成本,简化了标定过程,为十字结构光传感器的工程化应用奠定了基础。通过对圆的直径和中心坐标的测量实验,结果表明,该方法切实可行。 相似文献
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提出一种新的摄像机标定方法,该方法基于2D共面参照物摄像机标定方法和相移技术.首先由摄像机记录已知相位分布的平面,通过相移计算出相位分布.对任意标定平面,两个正交相位分布与平面坐标的对应关系已知,由此可以建立像素坐标与2D平面坐标的一一对应关系.将该已知相位分布的平面在空间中放置不同的位置,分别完成上述测量,即可根据2D共面参照物摄像机标定方法完成摄像机的高精度标定.该方法避开了复杂的标定特征点提取,大大增加了2D标定数据量,提高了标定精度.实验和计算机模拟表明,该方法简单、可靠和精度高. 相似文献
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针对机器人视觉对便携式三维扫描系统的大景深要求,利用Scheimpflug条件对CCD平面进行偏转,成功地将扫描系统的景深从30mm提高到了100mm以上;并根据CCD偏转后的摄像机模型,在理论上完整地推导了便携式集成三维扫描系统的物像关系方程。针对景深扩大后带来的测量精度降低的问题,提出了一种对系统全景深范围进行分段校准的新方法,提高了测量精度与系统分辨率。三维重建时,根据被扫描物体所对应的图像点在像平面上的不同位置分别调用不同的标定参数将二维图像坐标转变为物体的空间坐标,测量精度可以达到0.06mm。 相似文献
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大视场线结构光视觉传感器的现场标定 总被引:2,自引:0,他引:2
针对大视场线结构光视觉传感器的现场标定,提出了一种基于自由组合一维靶标的标定方法。自由组合多个一维靶标并固定,其中每个一维靶标至少包含3个共线特征点。靶标在传感器测量空间内自由摆放至少两次。以一维靶标两两之间夹角恒定为约束求解摄像机内部参数;由一维靶标消影点性质和特征点之间距离约束,求解各特征点在摄像机坐标系下的空间坐标;根据交比不变计算光平面与各一维靶标交点的摄像机坐标,拟合出光平面方程。实验表明,该方法可获得与平面靶标相当的标定精度,具有靶标加工容易、精度高、摆放次数少的特点,适合大视场线结构光视觉传感器的现场标定。 相似文献
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为实现仅用一幅图象在真正的三维欧氏空间重构三维场景,尤其是动态的三维场景,系统需要对彩色伪随机编码闪光投影系统进行建模和预标定。当系统参数改变后,利用伪随机编码图案的几何约束,不需重新标定,可实现自适应重构三维场景。通过对投影仪像质的的无畸变性分析,用线性模型对投影仪成像过程进行建模,并提出一种高精度的投影系统直接标定方法,通过测出靶标上各投影编码特征点在空间的三维齐次坐标,求出内外参数实现了对投影仪的预标定。标定精度达到0.1单元格,欧氏重构结果较为理想。 相似文献
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Li YF Zhang B 《Journal of the Optical Society of America. A, Optics, image science, and vision》2007,24(3):785-793
We present a method for dynamic recalibration and 3D reconstruction via a structured light system. Assuming that the light planes cast from the digital light projector have been calibrated off-line, we show that the focal length, aspect ratio, and all motion parameters of the camera can be determined on-line. Then the 3D reconstruction can be carried out by either a traditional triangulation method or a more efficient transformation-based method. In the latter method, a single image is sufficient for the whole process of calibration and reconstruction. Thus a hand-held camera can be used. Computer simulation and real data experiments were carried out to validate the method. 相似文献
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In phase measurement profilometry (PMP), the projector can be regarded as another camera according to the reversibility of the light path principle. The relationship of projecting spatial points to image plane of camera and projector is studied, and the phase–height mapping equation without projector distortion is obtained. The equation is then expanded to a polynomial for the convenience of calibration. Furthermore, the relation between the distortion value and the phase is investigated. Finally the phase–height mapping algorithm considering projector distortion and its polynomial expression are acquired. The accuracy of approximation is studied and compared with another two existing algorithms by computer simulation. It is revealed that the absolute error of the new algorithm expressed with quartic polynomial reaches 5.380× 10?3 mm and its standard deviation reaches 3.354× 10?4 mm under general lens distortion. The accuracy of the new algorithm is the highest among the three algorithms. In experiment, the standard deviation of the measurement reaches 0.04 mm even though the result is affected by measurement error. 相似文献
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A novel approach to extract the depth data of 3D objects in space by using the computational integral imaging reconstruction (CIIR) technique is proposed. With elemental images of 3D objects captured by the CCD camera through a pinhole array, depth-dependent object images can be reconstructed on the output plane by the CIIR technique. Only the images reconstructed on the output planes where 3D objects were located are clearly focused; so the depth data of 3D objects in space can be extracted by discriminating these focused output images from the others by using an image separation technique. A feasibility test of the proposed CIIR-based depth extraction method is carried out, and its results are discussed as well. 相似文献
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A new acoustic grating fringe projector (AGFP) was developed for high-speed and high-precision 3D measurement. A new acoustic grating fringe projection theory is also proposed to describe the optical system. The AGFP instrument can adjust the spatial phase and period of fringes with unprecedented speed and accuracy. Using rf power proportional-integral-derivative (PID) control and CCD synchronous control, we obtain fringes with fine sinusoidal characteristics and realize high-speed acquisition of image data. Using the device, we obtained a precise phase map for a 3D profile. In addition, the AGFP can work in running fringe mode, which could be applied in other measurement fields. 相似文献