共查询到18条相似文献,搜索用时 78 毫秒
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针对视觉检测技术对大尺寸复杂零件测量精度低的问题,提出一种基于单应性矩阵的大尺寸零件视觉测量图像拼接方法。首先建立世界坐标系→相机坐标系→投影坐标系→图像坐标系之间的归一化模型,提炼出简单易懂的坐标变换表达式H;然后对摄像机进行多次标定,确定像素当量、拍摄视场及焦距;再获取零件图像,利用前面得到的最简坐标表达式H得到拼接图像之间的配准,最后完成若干副图像的拼接,把拼接结果和SURF特征点方法及向后映射模型归一化的拼接结果进行比较。结果表明,该方法可以大大减少大尺寸零件拼接的时间,较SURF特征点方法和向后映射拼接用时分别降低86.55%和67.30%,拼接精度远高于SURF特征点方法和向后映射方法,分别提高了50.95%和25.08%,测量精度满足大尺寸零件检测精度要求。 相似文献
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表面粗糙度的测量与评定一直是机械行业的重要课题。提出了一种基于机器视觉检测工件表面粗糙度的方法。首先利用显微镜获取端铣、刨、车不同等级下工件表面的序列图像,采用方差聚焦测度算子对序列图像中的每一个点进行高度计算;然后再利用高斯插值法计算出微观物体表面的准确高度,重构其表面微观形貌;最后计算出各个工件表面的三维粗糙度。通过对实验数据的分析和讨论,可以确定出表面均方根偏差Sq、表面偏斜度Ssk和表面峰密度Sds这三个参数,它们是常用地对工件表面粗糙度进行评价的可靠参数,可为以后三维粗糙度体系的科学建立提供依据。 相似文献
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Novel calibration method for non-overlapping multiple vision sensors based on 1D target 总被引:1,自引:0,他引:1
The global calibration of multiple vision sensors (MVS) with non-overlapping views has been widely studied. In this paper, a novel calibration method for MVS with non-overlapping fields of view based on 1D target is presented. First, two neighboring vision sensors are selected. The rotation matrix between the two vision sensors is computed using the co-linearity property of the feature points on 1D target. Then the translation vector is computed according to the known distances between feature points on 1D target. The global calibration of all vision sensors is realized by repeating the above pair-wise calibration on different pairs of vision sensors. Due to the small volume and mobility of 1D target, the proposed global calibration method can be applied to vision sensors distributed in a large area or narrow space. Experiment results show that the RMS error of global calibration is within 0.060 mm. 相似文献
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The accuracy of structured light measurement depends on delicate offline calibration. However, in some practical applications, the system is supposed to be reconfigured so frequently to track the target that an online calibration is required. To this end, this paper proposes a rapid and autonomous self-recalibration method. For the proposed method, first, the rotation matrix and the normalized translation vector are attained from the fundamental matrix; second, the scale factor is acquired based on scale-invariant registration such that the actual translation vector is obtained. Experiments have been conducted to verify the effectiveness of our proposed method and the results indicate a high degree of accuracy. 相似文献
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数码相机通过将景物取样成一系列像素来记录景物,而且每个像素的亮度取决于景物接收的光通量———照度。基于这一原理进行了闪光灯投影系统照度分布测试实验。首先通过数码相机采集被照物面的灰度图,然后用Photoshop图像处理软件和Matlab软件对图片进行量化分析处理,最终得到了闪光灯投射系统的照度分布情况。该测试方法简单、新颖,测试精度可满足工程应用需要。 相似文献
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Zhiling Hou 《Optik》2010,121(14):1324-1329
In the three-dimensional (3D) phase measurement, some marks are usually adhered to the object in order to make the 3D registration process faster and easier. As covered with marks, local phase data are missing and have to be interpolated later. Considering the phase distribution nearby the marks, a gradient estimate (GE) interpolation algorithm is provided here. This algorithm recovers one pixel's missing phase value with the average of the estimated values which is calculated by gradients in eight directions nearby. Since this algorithm is a local processing, the missing phase values should be interpolated from the edge of the marks to the center. In the computer simulation and the practical experiment, compared with the same-size neighborhood mean (NM) algorithm and the Gerchberg-Saxton (GS) algorithm, this new algorithm achieves very good fit results with the least time. So it can be used as a practical tool for automatic missing phase interpolation. 相似文献
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基于光流分层方法的平面3D运动估测 总被引:1,自引:0,他引:1
无人机自主着舰末端视觉导引中舰机间相对位姿的估测,可以看作机载摄像机对甲板平面3D运动的估测。提出了一种光流分层方法:首先利用已知焦距的机载摄像机拍摄着舰靶标区域的图像序列,并采用Lucas方法计算相邻两帧图像的光流场;而后通过分层模型,将由光流场进行3D运动检测的非线性问题转化为了两个线性问题。该方法无需图像间的特征匹配,可线性解算出着舰靶标区域相对于无人机的三维运动参数,进而得到舰机间的相对位姿信息。计算机合成图和摄像机实拍图像的实验结果验证了该算法的正确性和有效性。 相似文献
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A novel measurement scheme for a three dimensional (3D) object's surface boundary perimeter is proposed. This scheme consists of three steps. First, a binocular stereo vision measurement system with two CCD cameras is devised to obtain the two images of a detected object's 3D surface boundary. Second, two B-spline active contours are applied to converge to the object's contour edges accurately in the two CCD images to perform the stereo matching. Finally, for the reconstructed 3D active contour, its true contour length is computed as the detected object's true boundary perimeter. An experiment on a bent surface's perimeter measurement indicates that this scheme's measurement repetition error decreases to 0.6%. 相似文献
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Junhua Sun Qianzhe Liu Zhen LiuGuangjun Zhang 《Optics and Lasers in Engineering》2011,49(11):1245-1250
Large FOV (field of view) stereo vision sensor is of great importance in the measurement of large free-form surface. Before using it, the intrinsic and structure parameters of cameras should be calibrated. Traditional methods are mainly based on planar or 3D targets, which are usually expensive and difficult to manufacture especially for large dimension ones. Compared to that the method proposed in this paper is based on 1D (one dimensional) targets, which are easy to operate and with high efficiency. First two 1D targets with multiple feature points are placed randomly, and the cameras acquire multiple images of the targets from different angles of view. With the fixed angle between vectors defined by the two 1D targets we can establish the objective function with intrinsic parameters, which can be later solved by the optimization method. Then the stereo vision sensor with two calibrated cameras is set up, which acquire multiple images of another 1D target with two feature points in unrestrained motion. The initial values of the structure parameters are estimated by the linear method for the known distance between two feature points on the 1D target, while the optimal ones and intrinsic parameters of the stereo vision sensor are estimated with non-linear optimization method by establishing the minimizing function involving all the parameters. The experimental results show that the measurement precision of the stereo vision sensor is 0.046 mm with the working distance of about 3500 mm and the measurement scale of about 4000 mm×3000 mm. The method in this paper is proved suitable for calibration of stereo vision sensor of large-scale measurement field for its easy operation and high efficiency. 相似文献
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用数码相机实现未琅禾费衍射测量细丝直径 总被引:5,自引:1,他引:4
介绍利用激光获得丝夫琅禾费衍射图样,并采用数码相机实现计算机辅助非接触自动测量细丝直径的方法,以及将其用于设计性实验的尝试。 相似文献