共查询到19条相似文献，搜索用时 125 毫秒
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通过长期的生产实践提出了相对定向不定性的问题，从相对定向的数学关系着手，列出解求相对定甜元素的方程组，分析了产生相对定向不定性的原因，提出了相对定向的结果必须是模拟显示结果与数字显示结果的统一。 相似文献
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提出了一种基于相交直线的相对定向方法,提取同名相交直线特征,根据相交条件方程获得相对定向元素。该方法完全不需要同名点数据,能够解决因同名点不足而无法准确定向的问题。通过航空影像、近景影像和倾斜影像的实验表明,该方法能够获得稳定的相对定向结果。采用本文提出的算法与传统的相对定向方法进行联合平差,能够进一步提高相对定向结果的精度和稳定性。 相似文献
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针对无人机拍摄的大数据量大倾角影像三维重建,为获取影像的相对位姿,解决影像相对定向迭代不收敛、鲁棒性低等问题,提出了一种基于全局一致性优化的无人机相对定向方法。通过对增量式相对定向算法全局一次性平差优化改进,得到影像的高精度位姿信息。实验表明,该方法进行相对定向的效率与精度得到明显提高,并具有较好的鲁棒性。 相似文献
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进入90年代,数字摄影测量得到了飞速发展,相继有许多数字摄影测量系统出现。本文对数字摄影测量系统的基础之一——数字相对定向作了理论和实验研究,提出了一种基于特征点组的金字塔结构的自动相对定向方法,即用Fstner算子选择定向点,用金字塔结构影像数据相关定向点,最后用最小二乘相关获取的点位进行相对定向计算。实验证明,该方法是可行的,取得了满意的结果。 相似文献
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针对无人机在区域范围拍摄的低空遥感影像数量多,且相邻影像间存在旋转、尺度变化大等导致的立体定向困难问题,本文提出一种适用于无人机影像自动相对定向及模型连接的流程。即利用SURF算法对区域无人机影像进行特征提取后,连续相对定向及模型连接过程使用结合相对定向模型的RANSAC算法去除错匹配点,并针对RANSAC算法选取样本匹配点对容易陷入局部最优问题进行改进,提高了结果精度。 相似文献
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光学机械法的相对定向在一般情况下,只要按一定的方法在所选择的五个标准点上把上下视差消除为零,即五对相应光线两两相交,我们便认为所建立的地面模型是正确的。但是也会遇到由于摄影地区的实际地形使得我们不可能选择出五个标准点,如象主点落水,半象对落水等情况。此时若仍按普通的定向方法,就不可能尽快地完成相对定向,同时也不可能获得精度尽可能高的相对定向结果。为此本文对几种特殊情况的相对定向过程及其精度作一些讨论和分析,以供参考。 相似文献
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改进了传统近似垂直摄影条件下的立体像对相对定向算法,提出了一种基于倾斜摄影条件下的解算立体像对相对方位元素的新算法,并将其应用于不同视角倾斜影像组成的立体像对的相对定向。以单独像对相对定向系统为基础,重新推导了小倾斜情况下的共面条件方程形式,进一步分析了大倾斜情况下的解算工作,给出了重新确定相对方位元素初值和对倾斜像片像点坐标进行旋转变换这两种方案。为了验证本文方法的正确性,用Z/I DMC面阵数字相机拍摄的嵩山地区检校场的航空影像进行测试。实验结果表明:本文提出的方法能够解决倾斜摄影条件下非下视影像或旋角过大影像的相对定向问题,解算结果满足了相对方位元素精度要求。 相似文献
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球面全景影像相对定向与精度验证 总被引：1，自引：1，他引：0
对传统的5点法相对定向算法的共面误差计算方法进行改进,提出了一种适合球面全景成像特点的相对定向计算流程。与传统方法相同,该算法首先计算本质矩阵,然后对本质矩阵进行奇异值分解得到旋转矩阵和平移矢量的候选解,最后利用重建的物方三维点坐标排除错误解。本文的贡献在于推导了球面全景共面条件公式,并使用点到核线平面的球面距离作为球面全景共面条件的误差项。模拟数据试验显示:当图像特征点的随机噪声在[-0.5,0.5]像素范围内时,3个姿态角的中误差约为0.1°,由相对定向恢复的相对平移量与模拟值的夹角中误差约为1.5°。使用车载全景相机配合POS获取的数据进行试验的结果显示:横滚角和俯仰角的中误差可以达到0.2°以内,航向角的中误差可以达到0.4°以内,由相对定向恢复的相对平移量与POS平移量的夹角中误差可以达到2°以内。采用本文相对定向算法的结果生成球面全景核线影像,提取影像之间同名点坐标并计算其列方向误差,结果显示核线影像同名点列坐标差的中误差在1个像素以内。 相似文献
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多倍投影测图仪测图速度的加速主要系于相对定向过程的加速,在全能法仪器中相对定向是通过光学机械解法来实现的。要加快测图的速度,要加快相对定向的速度必须从光学机械解法来找寻途径。本文阐述了一般性的相对定向公式和光学机械法的联系,过度改正倍数,以及为加快相对定向的速度提出一些建议和措施。 相似文献
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The use of small computers for on line data processing in photogrammetry has developed from the desktop calculators of the early 1970s to the microcomputers of today. The restrictions of machine code programming, small memory and limited display have been overcome. Software has been written for the PI-1A monocomparator using the BBC microcomputer for a calibration test, relative orientation, and strip formation and adjustment in the on line mode. This low cost system is suitable for training inexperienced operators or students in analytical photogrammetry, with the sequence of observation guided by operator prompts and with error checking computations displayed. Re-observations can be made on line and acceptable observations stored for input to the strip adjustment program or subsequent block adjustment. 相似文献
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从独立法相对定向和连续法相对定向的数学模型出发,分析并得到在独立法相对定向和连续法相对定向中分别作为基准坐标系的基线坐标系与左方像空间坐标系间的转换关系,进而推导并给出独立法和连续法相对定向元素的直接转换的具体方法。仿真数据与真实数据实验结果表明:基于传统算法解算得到的独立(连续)法相对定向元素,可使用本文算法转换为连续(独立)法相对定向元素,且其相对定向精度指标与传统算法解算得到的连续(独立)法相对定向元素精度指标相当,满足实际生产精度要求。 相似文献
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Yongjun Zhang Binghua HuJianqing Zhang 《ISPRS Journal of Photogrammetry and Remote Sensing》2011,66(5):700-707
In digital photogrammetry, corresponding points have been widely used as the basic source of information to determine the relative orientation parameters among adjacent images. Sometimes, though, the conventional relative orientation process cannot be precisely implemented due to the accumulation of random errors or in the case of inadequate corresponding points. A new relative orientation approach with multiple types of corresponding features, including points, straight lines, and circular curves, is proposed in this paper. The origin of the model coordinate system is set at the projection center of the first image of a strip, and all of the exterior orientation parameters, except φ and ω of the first image, are set at zero. The basic models of relative orientation with corresponding points, straight lines, and circular curves are discussed, and the general form of a least squares adjustment model for relative orientation based on multi-features is established. Our experimental results show that the proposed approach is feasible and can achieve more reliable relative orientation results than the conventional approach based on corresponding points only. 相似文献
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This paper presents a method for relative orientation using feature-based matching techniques. Both the interest operator and feature-based matching are used to select distinctive points and measure their parallaxes for relative orientation automatically. After the feature-based matching a fine least-squares matching is performed in order to improve accuracy. The matched points are then used for the relative orientation. The precision of relative orientation depends on the final least-squares matching. Some aspects of the least-squares matching have also been studied. An off-line experiment was carried out. Results of 2.08 μm for the standard error of unit weight (σ0) of the γ-parallax for a simulated stereo model and 3.83 μm for a real stereo model are obtained. The estimated precision of feature-based matching together with least-squares matching for stereo parallax measurement is 0.06 pixels. The experiment also shows the high potential for automating the relative orientation procedure. 相似文献
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Yongjun Zhang Xu Huang Xiangyun Hu Fangqi Wan Liwen Lin 《ISPRS Journal of Photogrammetry and Remote Sensing》2011,66(6):809-817
Relative orientation based on the coplanarity condition is one of the most important procedures in photogrammetry and computer vision. The conventional relative orientation model has five independent parameters if interior orientation parameters are known. The model of direct relative orientation contains nine unknowns to establish the linear transformation geometry, so there must be four independent constraints among the nine unknowns. To eliminate the influence of over parameterization of the conventional direct relative orientation model, a new relative orientation model with four independent constraints is proposed in this paper. The constraints are derived from the inherent orthogonal property of the rotation matrix of the right image of a stereo pair. These constraints are completely new as compared with the known literature. The proposed approach can find the optimal solution under least squares criteria. Experimental results show that the proposed approach is superior to the conventional model of direct relative orientation, especially at low altitude and close range photogrammetric applications. 相似文献
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Relative orientation is one of the fundamental steps in forming a photogrammetric model. Whilst relative orientation is straightforward in most cases of aerial photogrammetry this may not be the case in close range photogrammetry where the nature of the photographs and the cameras being used often raise unfamiliar problems. This paper addresses the problem of performing relative orientation of non-metric photographs under unstable conditions where there are no ground control points and the ray intersection geometry is poor. The relative orientation problem is approached from several viewpoints, including a method that relies on little information about the exterior or relative orientation parameters. The solution is based on an iterative process, in which a set of three virtual control points (VCPs) is created, using photo coordinates and range ratios. The validity of the VCPs is checked during every iteration by an estimation of the coplanarity condition using two or more conjugate checkpoints. During the iteration a database is formed, which is then used to obtain a net of VCPs that fulfil the coplanarity condition for the checkpoints. The VCPs are then used to compute the "relative" exterior orientation by space resection. The proposed method was tested on both simulated and real photographs and was found to have some advantages over more commonly used techniques. 相似文献
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分析了SVG关键技术和优势,阐述了其在GIS地图数据中的显示和更新、地图要素的表示和分层及地图路径定位等方面的应用,并对基于SVG的WebGIS系统结构进行了说明。 相似文献