Comparison between innovative techniques of photogrammetry (original) (raw)
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3D Modeling: Comparison of some Innovative Techniques of Photogrammetry
Several non-linear problems, typical of analytical photogrammetry and frequent in digital photogrammetry, can be solved with some easy procedures. In this work we propose a two-steps procedure based on two phases: Relative Orientation and Absolute Orientation, both characterized by non-linear functions. In the first step, it is firstly necessary to form the model, finding the solution of the Relative Orientation, and then to reconstruct the object considering the solution of the Absolute Orientation. Subsequently, once validated the technique of orientation of two images, a procedure for the orientation of three images is proposed. The introduction of a third image allows avoiding human decision to find the final solution. In order to find an easy solution for three-image orientation, each model coming from two images of a triplet is analyzed, computing the relative orientation thanks to an exhaustive research of preliminary values of its parameters. This non-conventional approach supplies the orientation of two images, taking into account information among four base solutions. Once each model is relatively registered, the absolute orientation is computed by using a linear parameterization. There is also a comparison between the method of the three photogrammetric images and a method of Computer Vision that allows low costs, automaticity and immediacy: the reconstruction of the 3D model from digital images is performed with algorithms of the Structure from Motion technique (SfM).
A Photogrammetric Method for Single Image Orientation and Measurement
2005
The aim of this paper is to present a photogrammetric method for determining the dimensions of flat surfaces, such as billboards, based on a single digital image. A mathematical model was adapted to generate linear equations for vertical and horizontal lines in the object space. These lines are identified and measured in the image and the rotation matrix is computed using an indirect method. The distance between the camera and the surface is measured using a lasermeter, providing the coordinates of the camera perspective center. Eccentricity of the lasermeter center related to the camera perspective center is modeled by three translations, which are computed using a calibration procedure. Some experiments were performed to test the proposed method and the achieved results are within a relative error of about 1 percent in areas and distances in the object space. This accuracy fulfills the requirements of the intended applications.
ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, 2013
The new advance in photogrammetry using the automatic procedures such as the famous algorithm which was proposed by David Lowe features descriptors and matching (SIFT) and then the recent development of external orientation (Nister (Stewenius et alii, 2006) or Snavely (Snavely et alii, 2010)) have changed drastically the way of measuring space with photogrammetry. The complexity of the process and the huge quantity of processed data (thousands of photographs) makes difficult validating the different process steps. We propose in this paper several theoretical model generation methods in order to validate the complete photogrammetric orientation process. A theoretical photogrammetric model generation has been developed in order to produce photographs, photo orientation, 3D points and 2D observations according to some defined camera and a parametric photograph distribution in the scene. In addition the use of synthesis image software generation as POV-Ray allow us to generate set of photographs with pre-computed internal and external orientation in order to check the whole pipeline from feature extraction to Photographs External Orientation. We apply this model generation approach to several typical geometry of photogrammetric scene, stereo, parallel triplet, parallel strip and convergent models.
Applied Optics, 2008
Photogrammetry is a science with many fields of application in civil engineering where image processing is used for different purposes. In most cases, the use of multiple images simultaneously for the reconstruction of 3D scenes is commonly used. However, the use of isolated images is becoming more and more frequent, for which it is necessary to calculate the orientation of the image with respect to the object space (exterior orientation), which is usually made through three rotations through known points in the object space (Euler angles). We describe the resolution of this problem by means of a single rotation through the vanishing line of the image space and completely external to the object, to be more precise, without any contact with it. The results obtained appear to be optimal, and the procedure is simple and of great utility, since no points over the object are required, which is very useful in situations where access is difficult.
2011
Automatic image orientation of close-range image blocks is becoming a task of increasing importance in the practice of photogrammetry. Although image orientation procedures based on interactive tie point measurements do not require any preferential block structure, the use of structured sequences can help to accomplish this task in an automated way. Automatic orientation of image sequences has been widely investigated in the Computer Vision community. Here the method is generally named "Structure from Motion" (SfM), or "Structure and Motion". These refer to the simultaneous estimation of the image orientation parameters and 3D object points of a scene from a set of image correspondences. Such approaches, that generally disregard camera calibration data, do not ensure an accurate 3D reconstruction, which is a requirement for photogrammetric projects. The major contribution of SfM is therefore viewed in the photogrammetric community as a powerful tool to automatically provide a dense set of tie points as well as initial parameters for a final rigorous bundle adjustment. The paper, after a brief overview of automatic procedures for close-range image sequence orientation, will show some characteristic examples. Although powerful and reliable image orientation solutions are nowadays available at research level, there are certain questions that are still open. Thus the paper will also report some open issues, like the geometric characteristics of the sequences, scene's texture and shape, ground constraints (control points and/or free-network adjustment), feature matching techniques, outlier rejection and bundle adjustment models.
Quick Solutions Particularly in Close Range Photogrammetry
2003
In this work we tried to solve some non-linear problems of analytic photogrammetry. These problems are also widely flowed into the digital photogrammetry. The model formation considering the solution of the Relative Orientation, and the object reconstruction considering the solution of the Absolute Orientation have non-linear functional models. These models need an exhaustive research of the preliminary values (of parameters) for the Relative Orientation, and a transformation of the parameters able to transform the problem of the Absolute Orientation in a simple linear problem. In model formation we used the coplanarity condition and even if we could not find the correct solution, we made (only for the Relative Symmetric Orientation) a research of all possible preliminary values and, among these values, we managed to select only 4 possible configurations. In the object reconstruction, using the Rodriguez matrix, we managed to solve a linear problem finding an exact solution. A wide ...
Ghana Mining Journal, 2019
High cost of metric photogrammetric cameras has given rise to the utilisation of non-metric digital cameras to generate photogrammetric products in traditional close range or terrestrial photogrammetric applications. For precision photogrammetric applications, the internal metric characteristics of the camera, customarily known as the Interior Orientation Parameters, need to be determined and analysed. The derivation of these parameters is usually achieved by implementing a bundle adjustment with self-calibration procedure. The stability of the Interior Orientation Parameters is an issue in terms of accuracy in digital cameras since they are not built with photogrammetric applications in mind. This study utilised two photogrammetric software (i.e. Photo Modeler and Australis) to calibrate a non-metric digital camera to determine its Interior Orientation Parameters. The camera parameters were obtained using the two software and the Root Mean Square Errors (RMSE) calculated. It was ob...
TOWARDS EFFICIENCY OF OBLIQUE IMAGES ORIENTATION
Many papers on both theoretical aspects of bundle adjustment of oblique images and new operators for detecting tie points on oblique images have been written. However, only a few achievements presented in the literature were practically implemented in commercial software. In consequence often aerial triangulation is performed either for nadir images obtained simultaneously with oblique photos or bundle adjustment for separate images captured in different directions. The aim of this study was to investigate how the orientation of oblique images can be carried out effectively in commercial software based on the structure from motion technology. The main objective of the research was to evaluate the impact of the orientation strategy on both duration of the process and accuracy of photogrammetric 3D products. Two, very popular software: Pix4D and Agisoft Photoscan were tested and two approaches for image blocks were considered. The first approach based only on oblique images collected in four directions and the second approach included nadir images. In this study, blocks for three test areas were analysed. Oblique images were collected with medium-format cameras in maltan cross configuration with registration of GNSS and INS data. As a reference both check points and digital surface models from airborne laser scanning were used.
Application of Photogrammetry in 3D Scanning of Physical Objects
TEM Journal, 2019
This paper explains the 3D scanning procedure of creating a virtual 3D model from photographs by using a process called photogrammetry. It starts by giving a technical explanation of different technologies for 3D scanning, explains why photogrammetry was chosen and gives general specifications of hardware and software used in the process. The whole procedure is then thoroughly shown step by step on a physical object, and in the end an analysis of the generated 3D model and its variations is given.