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authors Ebrahim, Mostafa Abdel-Bary
year 1997
title Application and evaluation of digital image techniques in close range photogrammetry
source University of Innsbruck
summary Most of the orthomapping techniques that are used in the present are restricted to surfaces that arise from a function of 'ground co- ordinates' z = f (x, y) , so-called 2.5D objects. Some techniques are also restricted to surfaces with kind of smooth shape or even to regular surfaces, but all of them are established to rectify images (although increasingly digitally). A new approach has been established for digital restitution and orthomapping of close range objects of almost any shape and size and with almost no restriction to images or objects. The idea of this approach is an inversion of the photographic technique and is (on the contrary to the 'rectification approach') strictly object oriented. All of the objects are regarded to be describable in their geometrical shape by a number of particular faces that can be regular or irregular but can anyway be created in a CAD environment. The data needed to get this surface can come from any photogrammetric, tachometric or other source with any particular one wants to have for the results. All the details that lie on that surface don't have to be restituted by analog or analytical point measurement but can after that be projected onto this surface from any photo, from any side and with any camera they have been taken. A 'Digital Projector' does the projection of the photos from the same positions and with the same inner orientation as of photographic camera. Using this approach any measurements of any details on the facades can be done easily. No details of the object can be neglected, none can be forgotten, no prior filtering of details has preceded this using. The full information of the original photos is available in the results. The results of the restitution can be presented in many ways. One of them is create orthoimages in any scale. Other results are any perspective or parallel view of the object. Other use of the strict 3D map-covered object for visualization (e.g. in architecture and archaeology application) is possible  
keywords Digital Image; Digital Projector; Close Range Photogrammetry; Architectural Photogrammetry; 2.5d Objects; Visualization
series thesis:PhD
references Content-type: text/plain
last changed 2003/02/12 21:37
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