共查询到20条相似文献，搜索用时 31 毫秒
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The Z/I Imaging Digital Camera System 总被引：1，自引：0，他引：1
Market needs for airborne and spaceborne imagery used in photogrammetry and GIS applications are changing. Fundamental changes in sensors, platforms and applications are currently taking place. Most recently, new high resolution spaceborne sensors have become available. Besides classical photogrammetry, new thematic applications will drive the future image market. Savings in cost and time, together with the need for higher and reproducible radiometric resolution or spectral information will push forward the change from analogue to digital imagery. High resolution satellites will compete with airborne film-based photography and digital camera systems.
With the availability of a digital airborne camera, it is possible to completely close the digital chain from image acquisition to exploitation and data distribution. The key decision regarding the camera design in this case is whether a linear or area array sensor should be used. In view of the high geometric accuracy requirements in photogrammetry, Z/I Imaging has focused development on a digital camera based on an area sensor. An essential aspect of this decision was not only the aerial camera system, but also the entire photogrammetric process to the finished photographic or mapping product. If this point of view is adopted, it becomes clear that the development of a digital camera involves more than simply exchanging film for silicon. Aspects such as data transfer rates, in-flight data processing and storage, image archiving, georeferencing, colour fusion, calibration and preprocessing have the same influence on the economic assessment of a digital camera system. This paper describes current development activities and application aspects of a digital modular airborne camera system. 相似文献
With the availability of a digital airborne camera, it is possible to completely close the digital chain from image acquisition to exploitation and data distribution. The key decision regarding the camera design in this case is whether a linear or area array sensor should be used. In view of the high geometric accuracy requirements in photogrammetry, Z/I Imaging has focused development on a digital camera based on an area sensor. An essential aspect of this decision was not only the aerial camera system, but also the entire photogrammetric process to the finished photographic or mapping product. If this point of view is adopted, it becomes clear that the development of a digital camera involves more than simply exchanging film for silicon. Aspects such as data transfer rates, in-flight data processing and storage, image archiving, georeferencing, colour fusion, calibration and preprocessing have the same influence on the economic assessment of a digital camera system. This paper describes current development activities and application aspects of a digital modular airborne camera system. 相似文献
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智能手机移动测量方法的设计与实现 总被引：2，自引：0，他引：2
近年来,智能手机在快速的发展过程中逐渐集成了多种传感器,包括位置传感器、磁力计和加速度计等姿态传感器和数码相机等;同时,由于它所具备的体积小、成本低的优点,为实现手机影像移动量测提供了可能。本文通过Android系统平台及智能手机集成的多传感器,提出了一种新型的智能手机影像量测方法。该方法首先对手机相机进行标定获取内方位元素,并进行Android应用程序的开发,在获取影像数据的同时获得手机的位置姿态数据;然后对影像数据进行特征点提取、匹配及错误点删除,并根据位置姿态数据和同名点图像坐标,利用空间前方交会计算目标点的三维坐标;最后通过光束法平差进行整体优化。试验结果表明该方法获取的位置信息可达到较高的精度. 相似文献
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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
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Still video cameras are easy to handle, portable, digital image acquisition devices for close range photogrammetry. They allow fast object recording without being connected to a computer. As an example of the new camera type, the high resolution Kodak DCS200 is presented in this paper, combined with the DPA digital photogrammetric station used for image measurement and object reconstruction. The performance of this three dimensional measurement system is illustrated by calibration results as well as applications to high precision dimensional inspection in industry. 相似文献
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D. Rieke-Zapp W. Tecklenburg J. Peipe H. Hastedt Claudia Haig 《ISPRS Journal of Photogrammetry and Remote Sensing》2009,64(3):248-258
Recent tests on the geometric stability of several digital cameras that were not designed for photogrammetric applications have shown that the accomplished accuracies in object space are either limited or that the accuracy potential is not exploited to the fullest extent. A total of 72 calibrations were calculated with four different software products for eleven digital camera models with different hardware setups, some with mechanical fixation of one or more parts. The calibration procedure was chosen in accord to a German guideline for evaluation of optical 3D measuring systems [VDI/VDE, VDI/VDE 2634 Part 1, 2002. Optical 3D Measuring Systems–Imaging Systems with Point-by-point Probing. Beuth Verlag, Berlin]. All images were taken with ringflashes which was considered a standard method for close-range photogrammetry. In cases where the flash was mounted to the lens, the force exerted on the lens tube and the camera mount greatly reduced the accomplished accuracy. Mounting the ringflash to the camera instead resulted in a large improvement of accuracy in object space. For standard calibration best accuracies in object space were accomplished with a Canon EOS 5D and a 35 mm Canon lens where the focusing tube was fixed with epoxy (47 μm maximum absolute length measurement error in object space). The fixation of the Canon lens was fairly easy and inexpensive resulting in a sevenfold increase in accuracy compared with the same lens type without modification. A similar accuracy was accomplished with a Nikon D3 when mounting the ringflash to the camera instead of the lens (52 μm maximum absolute length measurement error in object space). Parameterisation of geometric instabilities by introduction of an image variant interior orientation in the calibration process improved results for most cameras. In this case, a modified Alpa 12 WA yielded the best results (29 μm maximum absolute length measurement error in object space). Extending the parameter model with FiBun software to model not only an image variant interior orientation, but also deformations in the sensor domain of the cameras, showed significant improvements only for a small group of cameras. The Nikon D3 camera yielded the best overall accuracy (25 μm maximum absolute length measurement error in object space) with this calibration procedure indicating at the same time the presence of image invariant error in the sensor domain. Overall, calibration results showed that digital cameras can be applied for an accurate photogrammetric survey and that only a little effort was sufficient to greatly improve the accuracy potential of digital cameras. 相似文献
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Albert K. Chong Peter Milburn Richard Newsham-West Marieketer Voert 《The Photogrammetric Record》2009,24(127):264-279
Close range photogrammetry has been recognised as an essential tool for the capture of high-accuracy spatial data for medical applications, in particular work involving dynamic human body parts such as limbs. Offline and online photogrammetric systems are readily available for a number of common applications. However, off-the-shelf systems are not always appropriate because of project site conditions. To achieve high measurement accuracy in a field environment, a modified field camera calibration technique was introduced. The technique is particularly important where each camera is limited to one captured image during calibration, as the camera and the calibration testfield are in fixed positions. In this paper a custom-built imaging system designed for the study of the human spine in an outdoor environment is introduced. The discussion addresses: (1) imaging system design; (2) modified field calibration techniques; and (3) a case study on human spines. Two field camera calibration techniques were evaluated, both of which improved the accuracy of the prototype system, the use of a detachable target board offering the best results. This modified camera calibration procedure has improved the 3D measurement accuracy from 1·25 ± 0·3 mm to 0·43 ± 0·1 mm. The improvement is at a level achievable in the laboratory. The technique is considered to provide accurate and reliable anthropometric landmark measurement at low cost. This was evaluated in a clinical setting where diurnal changes in spine length and contour were measured in a cohort of 30 university students. The capability of the technique to measure sagittal and frontal angular changes provides a novel way of examining changes in spine shape. 相似文献
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Metric Exploitation of still Video Imagery 总被引：1，自引：0，他引：1
The development of still video CCD cameras with digital image storage has made feasible the concept of offline, single sensor vision metrology. This paper reports on practical evaluations of such a system for dimensional inspection of aircraft tooling and for structural monitoring for large scale engineering. A further application of still video technology for low altitude aerial mapping is also reported. In each case a Kodak DCS200 camera has been employed for the photography in order to take advantage of the relatively high sensor resolution and adequate on-board image storage capacity. Aspects of the measurement operations, which yielded object space accuracies to 1:80 000 in the industrial measurement projects, are discussed and the results analysed. 相似文献
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The aim of this study is to assess the impact of sensor size and resolution of different digital camera sensors upon the accuracy and precision of three dimensional data derived by photogrammetry. Kodak DC40, DCS420 and DCS460 digital cameras were used to produce digital images of retroreflective targets in a 4 m three dimensional test field. The image locations of the targeted points were automatically measured using an off the shelf image processing software package. Two different sub-pixel measurement approaches were examined: centre of gravity and weighted mean. From the automated sub-pixel measurement of the targeted points, results indicate that the high resolution DCS460 camera produces optimum results using either the weighted mean or centre of gravity approaches. Although this was perhaps expected, the far lower resolution DC40 camera performed better than was originally anticipated, suggesting potential for the cheaper DC40 for many applications. 相似文献
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Full automation in close-range photogrammetric measurement has long been a practical reality. However, constraints apply to the process such that automated 3D measurement is generally confined to targeted points in an environment of controlled illumination. The ready availability of consumer-grade digital cameras has made photogrammetric measurement accessible and more widely employed for a host of new applications, the majority of which call for 3D measurement of other than signalized object features. Process automation is therefore typically precluded. This paper discusses a hybrid measurement approach which involves fully automatic network orientation with targets, while at the same time supporting follow-up semi-automatic and manual operations such as feature point and line extraction and surface measurement via image matching. The topics discussed include camera calibration, the metric exploitation of colour attributes, issues related to image point correspondence determination, operator assisted feature measurement and surface extraction. All are important to the practical realisation of the hybrid measurement approach. 相似文献
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Digital Photogrammetry and Microscope Photographs 总被引：1，自引：0，他引：1
The feasibility of applying commercial digital photogrammetric software to the measurement of small objects photographed through an optical microscope has been examined. The objects, about 20 mm across, were photographed using a 35 mm film camera (at the lowest magnification setting of the Olympus microscope) giving photographs at a scale of 2:1. The photographs were then scanned before processing with the VirtuoZo digital photogrammetric system. Various problems needed to be overcome, some due to the limited options available with the highly automated digital system which was not designed for such measurement tasks. The unusual image scales, the uncommon pixel sizes and the unconventional and uncertain imaging geometry, all impeded immediate photogrammetric implementation. Photographic problems with the microscope were also faced, as with all microscope photogrammetry. Creating control points and independently assessing the accuracy of results at these scales were also difficult operations, but an analytical plotter was utilized for both these purposes and to verify the imaging geometry. Once such problems were overcome, image matching proceeded well and an accurate DTM could be created successfully, provided that a suitably textured object was chosen. 相似文献
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一种视觉引导经纬仪自动测量方法 总被引：1，自引：0，他引：1
文中将TM5100A经纬仪加载高精度摄像头构造视觉引导测量设备,标定十字丝中心点在像平面坐标系下的坐标,对经纬仪旋转水平角和垂直角与目标图像中心像素坐标之间的关系进行标定;摄像头采集目标图像并处理获取目标中心像素坐标,根据像素坐标与经纬仪旋转角关系计算经纬仪旋转角度,进而实现视觉引导经纬仪自动测量;对加载摄像头的经纬仪驱动误差进行测试,驱动误差允许的情况下测试并分析了视觉引导装置的点位测量精度、角度测量精度以及视觉引导准直测量精度,比人工测量精度高,符合工业测量的需求。 相似文献
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Systematic Geometric Image Measurement Errors of Circular Object Targets: Mathematical Formulation and Correction 总被引：2，自引：0，他引：2
The use of circular object targets is very common in spatial photogrammetric object reconstruction. An object circle is projected on to the image plane as an ellipse if the object plane and the image plane are not parallel to each other. The image co-ordinates of the centre of the ellipse are usually determined automatically by means of digital image processing. These co-ordinates are then used as observations for a subsequent reconstruction of the three dimensional object point. The image co-ordinates of the centre of the ellipse and the true co-ordinates of the projected centre of the circular object target are not identical; thus eccentricity is caused, resulting in systematic geometric image measurement errors. This paper describes the functional context of this eccentricity for a typical target/camera set-up. The possible solutions for a correction of this systematic eccentricity error are derived. Guidelines for the correct combination of object target sizes and exposure distances, guaranteeing reliable image point measurements and accurate object point determination, are proposed. 相似文献
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Jim H. Chandler Koji Shiono Ponnambalam Rameshwaren & Stuart N. Lane 《The Photogrammetric Record》2001,17(97):39-61
A critical problem in hydraulics research is accurate measurement of fluvially worked sediments, both in the field and in scaled representations of field situations in laboratory flumes. Such measurement must provide information on individual grain characteristics, and their organisation into structures referred to as bedforms. Existing measurement approaches are based upon mechanical or laser profiling devices, which are both expensive and take considerable time to acquire data, particularly where information is required at very high densities. This paper demonstrates how conventional automated terrain model extraction software, combined with image acquisition using a Kodak DCS460 digital camera, has been effective in generating digital elevation models of complex bed morphology. This has reduced time spent collecting data in the flume and has allowed data collection at much higher spatial and temporal densities. Application of the method is illustrated by research carried out at Hydraulics Research Wallingford. Issues discussed include configuration of photographs and control coordinates; appropriate camera calibration methods; stability of inner orientation of the Kodak DCS460; and accuracies obtained. Comparisons with independent check data reveal that accuracies of ±2.5mm have been achieved using a camera-to-object distance of 4.2 m. 相似文献
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数字工业摄影测量中,相机拍摄的不同相片得到的像点坐标被视为等精度观测值,其权值被定为单位权进行平差计算。自检校光束法平差能够有效的补偿系统误差,但测量过程中仍然不可避免地存在粗差和随机误差。为了进一步提高数字工业摄影测量平差计算结果的精度,结合抗差估计具有"充分利用有效信息,限制利用有用信息,排除有害信息"的特点,对自检校光束法平差方法进行改进,提出了一种基于IGG3的抗差光束法平差方法;并进行公共点转换实验和重复测量实验来评价其外符合精度和内符合精度。实验结果表明改进后的方法比原方法计算所得的结果精度更高。 相似文献
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普通数码相机在图像获取方面有着很多优势,但它是非量测化相机,不能用普通数字摄影测量方法对其数字图像进行处理。针对这一情况,本文提出了建立3维控制场对非量测数码相机进行检校,采用DLT（直接线性变换）方法计算出非量测数码相机的内外方位元素,实现非量测数码相机获取像对的可量测化。最后通过在黑龙江省地理信息产业园主楼区域建立3维控制场的试验,进行数据采集后获取了实际的3维模型。 相似文献
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关于新一代激光雷达系统 总被引：8，自引：0，他引：8
激光雷达系统配备有当今世界上最高分辨率的彩色数码相机和多光谱航拍相机。它同时集常用测量装置和全球定位装置于一身 ,当飞机机载该装置飞越地球表面时 ,它们能在获取所需图像及数据的同时 ,计算出传感器的精确位置和取向 ,给出数字高程图 (DEM)及全数码彩色影像。数码相机的底部配备着一个超大像幅的CCD传感器。该激光雷达系统还配置有一个高分辨率多光谱成形相机 ,因此多谱段像素直接与XYZ坐标值相对应 ,得以自动清晰地区分道路、建筑、树林、河流和其他地貌 相似文献