Optical 3-d digitizing of object surfaces can be performed by combining fringe projection measurement systems and close-range photogrammetry. Photogrammetry provides fast and precise reference point determination to merge several point clouds generated by the range sensor. In this paper, 3-d measurements using a COMET digitizing system in combination with the DPA-Win photogrammetric software are reported on. Different digital cameras (consumer, prosumer, professional type) can be applied. Tests were carried out to determine the accuracy of the photogrammetric reference network with respect to the number of images and/or reference points.
Digital cameras providing a 4k X 4k high resolution CCD area array sensor have been developed.; The acquired digital image data can be used for high precision photogrammetric object reconstruction, e.g. in industrial applications such as quality control and assurance. Technical specifications of some imaging systems are given in the paper. The metric quality of cameras based on the 4k X 4k Dicomed BigShot digital camera is determined from test measurements.
Digital camera backs to be connected with analogue photographic cameras have been developed for professional in-studio and in-field photography. The acquired high resolution digital images are also suitable for photogrammetric purposes. Technical specifications of these imaging systems are listed in this paper. The metric quality of selected camera backs is determined.
The Digital Photogrammetric Station DPA based on a PC has been realized as a measurement system for close-range photogrammetry. Different digital image sources can be implemented and a large variety of image processing and measurement tools are available for 2D and 3D object reconstruction. In this paper performance and accuracy of the DPA measurement system are described and evaluated, giving some examples concerning industrial and architectural photogrammetry.
3-D data of wave patterns generated by a ship or ship model in running water are used for the computation of the wave resistance. The results are suitable to optimize the ship design. A series of investigations was carried out to determine the wave heights photogrammetrically. The water surface around a test model in an open channel was photographed with four simultaneously released partial metric cameras. The visibility of the wave surface was improved by scattering small particles onto the water. Stereopairs were measured on an analytical plotter in order to obtain a 3-D point cluster. Digital object models and various follow-up products such as perspective representations, contour maps and profiles were derived with the DTM program system HIFI-88.
This paper introduces the Linhof METRIKA as a new 4" x 5" roll film camera for close-range photogram- metry. It was aimed to develop a robust, precise and moderately priced camera which is rather handy and light- weight despite of the 4" x 5" photo format. Lens cones of 90 mm (wide angle) and 150 mm are available equipped with focussing stops which reproducibly fix a set of interior orientation parameters. Film flattening is provided by both a vacuum system and reseau technique. The design of the camera allows the interchange of reseau plates with different reseau arrangements. All operating functions of the camera are electronically controlled. First results of test field calibrations are presented which certify the high accuracy and physical stability of the camera. In addition, examples of applications of the METRIKA to architectural and industrial photogrammetry are given.