基于DLT方法的非量测数码相机检校研究

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。     

数码相机可量测化的研制

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，本文进行了数码相机的可量测化研制，并将其投入实际应用。实际应用的结果证明研制工作是成功的。     

地面序列影像的高陡边坡高精度三维建模方法

本文针对高陡边坡地形特点,介绍一种基于普通数码相机的多基线地面摄影测量方法,重点研究了普通数码相机的量测化方法和高陡边坡序列数码影像的匹配方法。通过对普通数码相机的量测化,提高了高陡边坡地区数据采集的效率,降低了作业对影像控制和算法的要求;采用种子点与多重约束相结合的多基线匹配方式,解决了高陡边坡序列数码影像匹配中存在的遮挡多、左右片变形大、比例尺不一致等匹配难题。上述建模过程快速且能获得很高精度,实验表明三维建模的相对精度达1/8000~1/12000。     

量测化普通数码影像的随点生成核线匹配方法

基于普通数码影像的近景摄影测量算法成为目前摄影测量研究的热点,本文针对量测化普通数码影像的核线相关匹配特性,提出了一种随点生成核线匹配算法。实验数据表明该算法可在量测化普通数码影像上进行一维匹配,很好地提高了匹配精度和效率。     

基于非量测数码影像的古建筑三维模型重建

基于数字近景摄影测量技术,利用非量测数码相机与全站仪分开作业的方法,获取相关数据资料。本文结合一般摄影测量软件建立文物的DEM、生成三角网、提取点云信息、自动结算三维点坐标,再进行图像配准,解决纹理映射,从而实现古建筑物的三维建模。以沈阳建筑大学八王书院为例,利用三维近景摄影测量软件PPSG2.0对获取的非量测数码影像成功地进行了建模。     

JX4系统处理数码相机影像方法研究

非量测性的数码相机影像已成为摄影测量中应用研究的热点。本文提出了利用数字影像重采样实现数字摄影测量工作站(JX4)处理非量测性数码影像的理论与方法,并通过具体试验加以验证。试验结果表明,该方法可实现非量测数码影像的摄影测量一体化作业。     

基于普通数码相机的近景摄影测量方法与精度的试验研究

普通数码相机由于体积小、重量轻、价格低廉、像素几何位置精度高、影像可直接输入计算机进行处理等优点备受人们青睐。随着数字摄影测量技术的发展,数码相机分辨率的不断提高,人们开始考虑能否将普通数码相机应用于工程实践。本文以普通数码相机作为影像信息的获取手段,就控制点的数量、分布、精度、影像获取及其量测方法、数据处理解算方法、解算精度等问题进行了研究。     

基于2维DLT方法的普通数码相机检校

由于普通数码相机属于非量测相机,无法直接得知其内方位元素和畸变系数,因此使用数码相机获取测量数据前,需要对相机进行检校。采用2维DLT方法进行普通数码相机的检校,对已有的方法作出改进,采用反复迭代的方法,获得相机像主点坐标、主距以及畸变系数。     

测角法非量测数码相机实验室几何标定

非量测数码相机凭借其自身特有的优点,成为了摄影测量获取影像的主要设备之一,广泛应用于摄影测量中。由于其内方位元素和畸变参数未知,本文介绍了一种利用测角法进行几何标定的方法,通过测定平行光线的入射角度和其对应像片上的像点坐标,根据镜头畸变平方和最小的原则解算出内方位元素和畸变参数。研究表明该方法对主距、主点的标定精度可达到μm级,该方法用于非量测型数码相机的几何参数标定是完全可行的。     

基于普通数码相机的核线相关方法

用普通数码相机获取数字影像具有一定的优势，但由于普通数码相机是一种非量测相机，其数据处理需要特殊方法，介绍了一种适合普通数码相机进行核线相关的方法，实验数据表明该方法是可行的。     

Multiplotting With Images from the Kodak DCS420 Digital Camera

This paper explores the potential of a digital camera to produce multiple images suitable for plotting. The objective was to build a three dimensional database by linking triangulated images from a Kodak DCS420 digital camera with a computer aided measurement system. The system then supplied X, Y, Z data from x, y image co-ordinates captured off two or more images. Relative accuracy in object space was around 1;50 000.     

数字天顶摄影仪确定垂线偏差及其精度分析

给出了数字天顶摄影仪的基本结构和垂线偏差测量的基本算法,结合仪器和测量过程,分析了垂线偏差测量误差。数字天顶摄影仪的自动化程度和测量精度都高于传统的天文大地测量。     

基于单CCD相机和经纬仪的几何测量方法研究

传统视觉测量系统需要双CCD相机同时拍摄两幅不同角度的数字图像,成本昂贵且难以确定两CCD相机问的空间相对位置。为此,建立一种结合CCD相机的摄像功能和经纬仪高精度测角功能的视觉测量系统。基于该系统提出一种用单CCD相机实现双目视觉原理的数学模型。实验结果证明系统与数学模型的可行性。     

The Role of a Digital Intelligent Camera in Automating Industrial Photogrammetry

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.     

Photogrammetric Capabilities of the Kodak DC40, DCS420 and DCS460 Digital Cameras

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.     

Practical Influences of Geometric and Radiometric Image Quality Provided By Different Digital Camera Systems

Imaging systems founded on current digital camera technology are finding widespread use in high precision measurement applications. A single digital CCD camera, or an array of such cameras, equipped with ring lighting equipment is commonly used to acquire imagery of high contrast retroreflective targets placed on the object at discrete locations to signalize points of interest. The precise and accurate measurement of each imaged target location is a fundamental requirement if suitable measurement tolerances are to be obtained. Whilst such systems are undoubtedly capable of producing excellent results, the practical effects of target image quality on the photogrammetric measurement process is in need of careful consideration. This paper revisits some fundamentals of the optical imaging of retrotargets and investigates some abilities of a range of digital camera systems to provide images of retrotargets that are appropriate to the measurement process. Some experimental results are presented including the imaging of planar arrays of differing sized retrotargets at differing angles and exposures and a series of network analyses in which the level of target image intensity has been varied systematically.     

摄影测量在机械量测中的应用实例

介绍了利用CCD摄像机与实时数字近景摄影测量技术相结合建立的钣金件检测系统。本系统采用CCD摄像机对置于旋转平台上的钣金件摄取序列图像,利用钣金件的CAD设计数据作为初值,由理论严密的自检校光束法平差完成高精度的平差计算,并经后续处理,完成工业目标的自动检测。本系统以CAD设计数据作为先验知识,结合最小二乘影像匹配,实现目标特征的子像素的精确配准,从而实现钣金零件的自动量测。     

相机三维检校场的精密测量与稳定性分析

为满足摄影测量中相机检校的需要,选用一种室内相机检校场的精密测量方法与实验分析方法,对相机检校场进行检校。根据山东科技大学室内三维检校场中标志点的排列规则,点数众多的实际分布特点,选用高精度的经纬仪测量系统,选取最佳的仪器和基准尺摆放位置对检校场内的标志点进行测量。利用统计检验的方法对标志点点位的稳定性进行分析,判断出标志点稳定可以满足相机检校的需要。     

多相机数码影像光束法解算及精度分析

光束法算法通常用于解决同一相机影像的平差解算问题,文中探讨多相机数码影像的光束法解算方法,理论研究与实验分析相结合,研究建立多相机影像光束法的平差模型,并在相同条件下与单相机光束法解算结果相比较。结果表明,多相机数码影像光束法严密平差可解,且分别在不同的控制条件下与单相机光束法解算精度相当。