共查询到20条相似文献，搜索用时 31 毫秒
1.
A. S. Walker 《The Photogrammetric Record》1997,15(89):657-664
The revolution promised by digital photogrammetry is dependent on extensive, successful automation at many stages of the production process. The progress of automation is uneven. Digital cameras are not in widespread use. Scanners are available which include roll film transports and automated orientation, but set up for optimum tonal transfer remains interactive. Extensive automation of several operations on digital photogrammetric workstations, such as generation of digital terrain models, orthophotographs, mosaics and perspective scenes, contrasts with feature extraction, where robust products lag behind success in research. Progress towards practical automation to assist, but not replace, the human operator is significant, however, and examples are given from the Leica-Helava systems. 相似文献
2.
J. Dold 《The Photogrammetric Record》1998,16(92):199-212
In the past few years the automation of digital industrial photogrammetric systems has increased dramatically. Due to digital image processing software, coded targets and automatic matching methods, a huge number of photogrammetric measurement tasks can be fully automated. In many cases a "one button click" is enough to provide the three dimensional co-ordinates of measured points without any manual interaction, immediately after acquiring the images. The technology of intelligent cameras is a logical step towards automated photogrammetric measurements. An intelligent camera, which has an integrated computer, analyses the image immediately after it is taken. This technology provides not only a much shorter processing time for the images but also more control over the measurement process just when it is needed, during image acquisition. This takes place in the form of real time feedback.
This paper describes the role of a digital intelligent camera in the automation of an industrial photogrammetric measurement system and gives an overview of existing automation techniques in industrial photogrammetry. As an example of an intelligent camera, the performance of the new INCA digital intelligent camera, developed and manufactured by Geodetic Services, Inc. (GSI) and distributed by Leica, is described. 相似文献
This paper describes the role of a digital intelligent camera in the automation of an industrial photogrammetric measurement system and gives an overview of existing automation techniques in industrial photogrammetry. As an example of an intelligent camera, the performance of the new INCA digital intelligent camera, developed and manufactured by Geodetic Services, Inc. (GSI) and distributed by Leica, is described. 相似文献
3.
Innovations in Automation for Vision Metrology Systems 总被引：1，自引：0，他引：1
C. S. Fraser 《The Photogrammetric Record》1997,15(90):901-911
The advantages of vision metrology (VM) systems over their film-based counterparts, in terms of the degree of automation within the measurement process, were initially confined to the image mensuration stage. Of late, however, the potential of significantly raising the level of automation of offline and real time VM systems has been more fully exploited, to the point where full automation of the offline procedure has been realized. Innovative features such as automatic image point identification via coded targets, exterior orientation through automatically recognizable "control" groupings of target points, determination of image point correspondences within unlabelled point clouds, and real time tracking of multipoint, handheld measurement probes are now incorporated in industrial VM systems. Another significant innovation is the development of "smart" cameras with incorporated image processing and measurement capabilities which remove the necessity for transmitting image data to the host computer. This paper reviews recent innovations in automation and discusses their operational impact on practical VM applications. The concepts discussed are illustrated through reference to a modern VM system which supports offline and real time measurement. 相似文献
4.
目前广泛应用的月球统一控制网2005（Unified Lunar Control Network 2005,ULCN2005）是由1994年的克莱门汀（Clementine）影像和之前的遥感数据联合平差构建的。提出利用21世纪获取的分辨率更高、精度更好的多探测任务数据,建立新一代月球控制网的方案与关键技术。该方案基于全球覆盖的月球遥感影像与激光高度计数据的联合平差,同时利用在月球轨道侦察器窄角相机影像上能高精度定位的绝对定位精度在厘米级的5个激光棱角反射标志点作为绝对控制。此外,还通过新的无线电测量方法对嫦娥三号着陆器进行高精度定位,将其定位结果也作为一个新的绝对控制数据。新一代控制网构建的重点有高精度的轨道器严密及通用成像几何模型的构建、多任务多模态数据间的多尺度特征提取与匹配、最优化多重覆盖影像的选择、全月球整体平差等。基于新的数据和技术,新一代月球控制网的精度和点的密度有望远超ULCN2005。 相似文献
5.
Hierarchical approaches for automated photogrammetric surface measurement invariably employ image pyramids and image matching at multiple resolutions. Such an approach is also applicable in industrial photogrammetry where projected light patterns are used to provide texture on an otherwise texture-free surface. This paper describes a novel strategy for hierarchical surface measurement in which projected non-repeating target patterns are employed, rather than the lower-resolution levels of an image pyramid. Thus, although the final derived digital surface model is obtained by image matching, preliminary surface models which support the matching are obtained using the non-repeating patterns. These projected patterns allow a simplification of the triangulation phase since they offer the potential of a fast and unambiguous solution to the image point correspondence problem. Following an introduction to the non-repeating pattern strategy, integration of the approach into a multi-camera vision metrology system is described and some experimental measurements are summarized 相似文献
6.
针对传统特征提取算法的结果存在交叉紊乱、不连续、缺少拓扑关系等问题，本文提出了基于Morse理论的建筑物点云特征提取算法。首先定义三维表面模型上顶点的Morse函数指标；然后采用邻点比较法自动提取特征点；最后针对Morse-Smale复形的对偶性在建筑物拓扑特征中已无实际意义的问题，提出了单复形拓扑模型的提取与简化算法。试验结果表明，该算法能够获得清晰、连续、完整的建筑物特征线，实现对建筑物模型表面的完全分割；简化算法在保证建筑物特征线拓扑一致性的前提下，可以获取不同层次的建筑物拓扑特征，为建筑物模型的重建与可视化提供了保障。 相似文献
7.
Three-dimensional (3D) reconstruction and texture mapping of buildings or other man-made objects are key aspects for 3D city landscapes. An effective coarse-to-fine approach for 3D building model generation and texture mapping based on digital photogrammetric techniques is proposed. Three video image sequences, two oblique views of building walls and one vertical view of building roofs, acquired by a digital video camera mounted on a helicopter, are used as input images. Lidar data and a coarse two-dimensional (2D) digital vector map used for car navigation are also used as information sources. Automatic aerial triangulation (AAT) suitable for a high overlap image sequence is used to give initial values of camera parameters of each image. To obtain accurate image lines, the correspondence between outlines of the building and their line features in the image sequences is determined with a coarse-to-fine strategy. A hybrid point/line bundle adjustment is used to ensure the stability and accuracy of reconstruction. Reconstructed buildings with fine textures superimposed on a digital elevation model (DEM) and ortho-image are realistically visualised. Experimental results show that the proposed approach of 3D city model generation has a promising future in many applications. 相似文献
8.
S. Hinz M. Stephani L. Schiemann K. Zeller 《ISPRS Journal of Photogrammetry and Remote Sensing》2009,64(3):297-307
This article presents a modular photogrammetric recording and image analysis system for inspecting the material characteristics of transparent foils, in particular Ethylen–TetraFluorEthylen-Copolymer (ETFE) foils. The foils are put under increasing air pressure and are observed by a stereo camera system. Determining the time-variable 3D shape of transparent material imposes a number of challenges: especially the automatic point transfer between stereo images and, in temporal domain, from one image pair to the next. We developed an automatic approach that accommodates for these particular circumstances and allows reconstruction of the 3D shape for each epoch as well as determining 3D translation vectors between epochs by feature tracking. Examples including numerical results and accuracy measures prove the applicability of the system. 相似文献
9.
10.
F. Ackermann 《The Photogrammetric Record》1984,11(64):429-439
A procedure for digital image correlation is described which is based on least squares window matching. The immediate aim is high precision parallax assessment, point transfer, and point measurement. Experiments and theory have confirmed the high accuracy potential of the method. By implementation of charge coupled device (CCD) video cameras in an analytical plotter, an experimental hardware and software configuration has been established with which the operational on line application of digital image correlation for conventional photogrammetric measuring tasks can be tested. First results of calibration and performance of the system are presented. They allow optimistic conclusions as to the further development and practical application of digital image processing in photogrammetry. 相似文献
11.
轻便型移动测量系统能高效率、高速度地采集道路两旁丰富的地物信息,可以为城市三维建模提供丰富、准确的基础点云数据。本文结合系统构成、工作原理、全景影像采集及点云数据采集的特点,研究了基于轻便型移动测量系统的城市三维建模技术解决方案,满足了实际工程需要。 相似文献
12.
一种基于无人机序列图像的地形地貌三维快速重建方法 总被引：1，自引：0，他引：1
提出了一种基于无人机序列图像的地形地貌三维重建方法,该方法采用Harris特征点和SIFT特征向量来提取图像特征,实现图像配准;采用准透视投影模型和因子化方法对未标定的图像序列进行自动标定;通过高效次优解三角化方法获取三维点云坐标;通过准稠密化扩散算法对三维点云进行稠密化;采用捆绑调整算法提高了空间三维点云的精度;采用Possion表面重建方法对三维点云进行了网格化处理.本文为无人机序列图像的应用提供了一个新的思路,拓展了无人机的应用空间. 相似文献
13.
R. Calow G. Gademann G. Krell R. Mecke B. Michaelis N. Riefenstahl M. Walke 《ISPRS Journal of Photogrammetry and Remote Sensing》2002,56(5-6)
The correct positioning of the patient is an important demand in radiotherapy. Optical measurements seem appropriate, but special requirements of speed and accuracy must be met. A new photogrammetric system that captures patient surface data in real-time is introduced. It allows reproducible patient set-up, and monitors the patient's position during irradiation even when the patient is moving. It consists of two cameras and one projector and is based on the photogrammetric evaluation of stereo image pairs by projecting white light fringes onto the patient's body.The raw data of the 3D measurement is a sequence of point clouds. It can be evaluated together with other data modes common in radiotherapy for diagnosis and treatment planning. The system can be used as an additional verification tool for the correct positioning of the patient, and completely new applications emerge. 相似文献
14.
15.
The extraction of object features from massive unstructured point clouds with different local densities, especially in the presence of random noisy points, is not a trivial task even if that feature is a planar surface. Segmentation is the most important step in the feature extraction process. In practice, most segmentation approaches use geometrical information to segment the 3D point cloud. The features generally include the position of each point (X, Y and Z), locally estimated surface normals and residuals of best fitting surfaces; however, these features could be affected by noisy points and in consequence directly affect the segmentation results. Therefore, massive unstructured and noisy point clouds also lead to bad segmentation (over-segmentation, under-segmentation or no segmentation). While the RANSAC (random sample consensus) algorithm is effective in the presence of noise and outliers, it has two significant disadvantages, namely, its efficiency and the fact that the plane detected by RANSAC may not necessarily belong to the same object surface; that is, spurious surfaces may appear, especially in the case of parallel-gradual planar surfaces such as stairs. The innovative idea proposed in this paper is a modification for the RANSAC algorithm called Seq-NV-RANSAC. This algorithm checks the normal vector (NV) between the existing point clouds and the hypothesised RANSAC plane, which is created by three random points, under an intuitive threshold value. After extracting the first plane, this process is repeated sequentially (Seq) and automatically, until no planar surfaces can be extracted from the remaining points under the existing threshold value. This prevents the extraction of spurious surfaces, brings an improvement in quality to the computed attributes and increases the degree of automation of surface extraction. Thus the best fit is achieved for the real existing surfaces. 相似文献
16.
Blending photogrammetric and Structure from Motion techniques with Unmanned Aerial Vehicles (UAV) is a commonly used approach for the documentation and analysis of archaeological sites. Using the dense 3D point clouds generated from these techniques, two main photogrammetric products are created: orthophotos and Digital Surfaces Models (DSM). Depending on the UAV technology, the flight parameters, the topography and land cover of the flown area, DSMs and orthophotos are delivered with varying positional accuracies and output scales. In this paper, the positional accuracy and maximum allowable scale of these products generated by complete automation of flight mode and processing workflow are assessed. Moreover, three known International Mapping Standards (IMS) are validated using independent checkpoints, obtained by geodetic Global Navigation Satellite Systems receivers, in two Spanish study areas. The results show that accurate photogrammetric products adapted to the IMS can be successfully obtained by the automation of the photogrammetric workflow. 相似文献
17.
18.
三维激光扫描测量技术是当前测绘领域研究的热点。点云各个要素特征提取在三维建模中是非常重要的一个环节,也逐渐成为三维点云数据处理中的一个研究重点。目前对点云数据特征提取仍然存在一些问题,大多数算法的研究是针对栅格点云数据进行的,存在容易受到噪声数据的影响以及适应性不强等问题。本文在研究了现有的点云数据特征提取的方法的基础上,将法线差分算法应用到场景内地物提取中,从而实现场景中地物的特征提取。 相似文献
19.
对三维地理场景真实还原是数字孪生的核心技术要求之一,地理信息系统与游戏引擎的结合为城市实景三维建设提供了新思路。倾斜摄影数据是实景三维建设中重要的数字底板要素,针对游戏引擎加载倾斜摄影数据问题,以Unreal Engine 4渲染为例提出一种倾斜摄影三维模型数据转换方法。该方法利用原始数据的文件组织,通过数据解析获取转换信息构建数据读取树;迭代树节点时分别对几何数据与纹理数据进行转换,转换过程兼顾游戏引擎渲染资源所需物理属性,最终完成几何和纹理重组。将该方法应用于深圳市福田区倾斜摄影数据,实验结果表明,所提方法能准确实现倾斜摄影三维模型数据至Unreal Engine 4渲染资源的转换,可为类似三维模型数据转换问题提供理论与技术参考。 相似文献
20.
基于高分辨率影像的城市三维建模 总被引：2，自引：0，他引：2
介绍了利用倾斜摄影影像和垂直摄影影像相结合的三维城市重建方法，分析了利用有理多项式(RPC)恢复IKONOS立体影像的模型，在VirtuoZo上实现了基于有理多项式(RPC)恢复IKONOS立体影像的模型方法，并利用其快速影像匹配技术，实现了数字地面模型DEM和正射影像，实现了手动和半自动人工地物的采集，如房屋等三维几何坐标和结构的采集；自动获取了基于不同传感器所获得影像的建筑物表面纹理，从而实现了基于多种影像快速三雏城市建模。 相似文献