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In the valley of Bamiyan, Afghanistan, almost 2000 years ago, two big standing Buddha statues were carved out of the sedimentary rock of the region. They were 53 and 35 meters high and the Great one figured as the tallest representations of a standing Buddha. In March 2001 the Taleban militia demolished the colossal statues, as they were considered...
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... constraints while the found approximations are used in the following global matching method [Zhang et al., 1992]. In our application, images B and C of the metric data set were used to reconstruct the 3D model. A regular image grid with 9 pixels spacing was matched using a patch size of 9 × 9 pixels and 4 pyramid levels. As result, a point cloud of ca 178 000 points is obtained (Figure 4). Due to the smoothness constraint and grid-point based matching, the very small features of the dress were filtered or skipped. Therefore these important small features had to be measured manually. 3.2.2 Manual Measurements The dress of the Buddha is rich of folds, which are between 5 and 10 cm in width. Therefore only precise manual measurements can reconstruct the exact shape and curvature of the dress. Therefore the metric images are imported to the VirtuoZo stereo digitize module [Virtuozo NT, 1999] and manual stereoscopic measurements are performed. The three stereo-models A/C, A/B and B/C (Figure 2) are set up and points are measured along horizontal profiles of 20 cm increment while the folds and the main edges are measured as breaklines. With the manual measurement a point cloud of ca 76 000 points is obtained (Figure 5) and the folds on the dress are now well visible. based on a relaxation algorithm [VirtuoZo NT, 1999]. It uses both grid point matching and feature point matching. The important aspect of this matching algorithm is its smoothness constraint satisfaction procedure. With the For the conversion of the point cloud to a triangular surface mesh, a 2.5D Delauney triangulation is applied. Due to some holes in the cloud, the created mesh surface includes some big faces. Then the model is texturized with one image of the data set and the result is shown in Figure 6, right. Due to the smoothness constraints and grid-point based matching, the small folds on the body of the Buddha are not correctly measured and the point cloud of the statue and surrounding rock looks very smooth. For the modeling, a 2.5D Delauney triangulation is performed: without losing its topology, the 3D surface model of the Buddha is expanded to a plane by transforming the cartesian coordinate system to a cylinder coordinate frame. In the defined ρθζ cylinder frame, ζ is the vertical cylinder axis crossing the model center and parallel to the original Y-axis of the cartesian object coordinate system. ρ is the euclidean distance from the surface point to the z- axis and is the angle around the z- axis. The 2.5D triangulation was done in the plane and the final shaded model of the triangulated mesh is shown in Figure 7. The model looks a bit “bumpy“. This is due to small measurement errors and inconsistences in surface modeling. Then the central image of the metric data set is mapped onto the 3D geometric surface to achieve a photorealistic virtual model (Figure 8). The lower part of the legs are not modeled because in the used stereomodel the legs were not visible. In the point visualization of Figure 5 it is already possible to distinguish the shapes of the folds on the dress. This point cloud is not dense enough (except in the area of the folds) to generate a complete mesh with a commercial reverse engineering software. Therefore the generation of the surface is performed again with the 2.5D Delauney method, by dividing the measured point cloud in different parts. A mesh for each single point cloud is created and then all the surfaces are merged together with Geomagic Studio []. The folds of the dress are now well reconstructed and modeled, as shown in Figure 9. With the commercial software some editing operations of the meshes are also performed: - holes filling: polygon gaps are filled by constructing triangular structures, respecting the surrounding area; - noise reduction: spikes are removed with smooth functions; - edges correction: faces are splitted (divided in two parts), moved to another location or contracted; - polygons reduction: in some areas, the number of triangles is reduced, preserving the shape of the object. The final 3D model, displayed in Figure 10, shows also the reconstructed folds of the dress. Compared to Figure 7 this represents a much better result. For photorealistic visualization, the central image of the metric data set is mapped onto the model, as shown in Figure 11. Different tools are available to display 3D models, shareware or commercial software, with or without real-time performance, interactive or not. The generated model can be visualized with a software developed at our Institute and called Disp3D. It allows the visualization of a 3D model as point cloud, in shaded or textured mode, as well as with interactive navigation [Gruen et al., 2001]. One of the few portable formats to interactively display a 3D model like the reconstructed Buddha statue is the VRML. With free packages like Cosmo Player or Vrweb we can display and navigate through the model or automatically fly along some predefined paths (Figure 12). Computer animation software (e.g. Maya) is generally used to create animations of 3D models. An example is presented in ddha.mpg. They usually render the model offline, using antialiasing functions and producing portable videos like MPEG or AVI. Finally, a way to display static view of 3D models is based on anaglyph images. An anaglyph mixes into one image a stereoscopic view using the complementarity of colours in the RGB channels. With coloured glasses, one can then filter the image and see the depth information of the model (Figure 13). The 3D computer model that we reconstructed with the manual procedure is used for a physical reconstruction of the Great Buddha. At the Institute of Machine Tools and Production, ETH Zurich, R.Zanini and J.Wirth have recreated a 1:200 model statue of the Great Buddha. The point cloud of the photogrammetric reconstruction is imported in a digitally programmed machine tool (Starrag NF100). The machine works on polyurethane boxes and follows milling paths calculated directly from the point cloud. The physical model is created in three steps: (1) a roughing path, (2) a pre-smoothing path and (3) the final smoothing path. The time needed for preparing the production data was about 2 hours while the milling of the part itself was done in about 8 hours. The computer reconstruction of the Great Buddha of Bamiyan, Afghanistan has been performed successfully using various digital photogrammetric techniques. We have presented here three versions of the 3D model, based on automated point cloud generation using four internet images, automated point cloud generation using three metric images and manual measurements using three metric images. While the automated matching methods provide for dense point clouds, they fail to model the very fine details of the statue, e.g. the folds of the robe. Also, some other important edges are missed. Therefore, only manual measurements allowed to generate a 3D model accurate and complete enough to serve as the basis for a possible physical reconstruction in situ. The problems encountered with the orientation of amateur images and with automated matching could be solved in an acceptable manner. The main difficulties of this project consisted in the transition from the point cloud (including breaklines) to a surface model which can satisfy high modeling and visualization demands. Since automated image matching does not take into consideration the geometrical conditions of the object, it is very difficult to turn such more or less randomly generated point clouds into TIN or wireframe structures of high quality and without losing essential information. Commercial reverse engineering software could also not generate correct meshes (mainly because the point cloud is not dense enough in some parts) and conventional 2.5D Delauney triangulation was used. When measurements are done in manual mode it is crucial for the operator to understand the functional behaviour of the subsequently activated 3D modeler. An on-line modeler would be very beneficial, as during the point measurements, the results of this modeler could be directly plotted onto the stereomodel and the operator could control the agreement of the on-line model with the measurements and the structure of the object. A web site of the work has been established on our server and is available at with more technical details and animations. The authors would like to thank Yuguang Li for the manual measurements on the metric images, Robert Zanini, Joachim Wirth and the Institute of Machine Tools Production, ETH Zurich, for the physical reconstruction of the statue at scale 1:200, Tom Bilson, Courtauld Institute of Art, London, for some Internet images of the Bamiyan statues and all the web sites where we found images and information on the Bamiyan statues. Baltsavias, E., 1991: Multiphoto Geometrically Constrained Matching. Dissertation, IGP, ETH Zürich, Mitteilungen No. 49, 221pages. Finsterwalder, S., 1896: Zur photogrammetrischen Praxis, pp. 225-240. Finsterwalder, S., Hofmann, W., 1968: Photogrammetrie. De Gruyter Lehrbuch, Berlin, pp. 119-120. Grün, A., 1985: Adaptive Least Squares Correlation: A powerful Image Matching Technique. South Africa Journal of Photogrammetry, Remote Sensing and Cartography, 14 (3), pp. 175-187. Grün, A., Baltsavias, E., 1988: Geometrically Constrained Multiphoto Matching. Photogrammetric Engineering and Remote Sensing, Vol. 54, No. 5, pp. 633-641. Grün, A., Zhang, L., Visnovcova, J., 2001: Automatic Reconstruction and Visualization of a Complex Buddha Tower of Bayon, Angkor, Cambodia. Proceedings of 21 th Wissenschaftlich Technische Jahrestagung of Deutsche Gesellschaft für Photogrammetrie und Fernerkundung (DGPF), 4-7 September, Konstanz, Germany, pp.289-301. Grün, A., Remondino, F., Zhang, L., 2002: Reconstruction of the Great Buddha of Bamiyan, Afghanistan. International Archives of Photogrammetry and Remote Sensing, 34(5), pp. 363-368, Corfu (Greece) ...
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... One of the first world wide famous application of the RE technology for cultural heritage is dated in 1999, when a laser scanner with a working volume of 3 m (width) by 7.5 m (height) was utilized to scan Michelangelo's David on its pedestal [9]. In 2003, the digital reconstruction of the great Buddha statue in Bamiyan, Afghanistan, was obtained using different types of images [10]. ...
In recent years, reverse engineering has achieved a relevant role in the cultural heritage field. The availability of 3D digital models of artefacts opens the door to a new era of cultural heritage: virtual museum creation, artefact cataloguing, conservation, planning and simulation of restoration, monitoring of artefacts subjected to environmental degradation, virtual reconstruction of damaged or missing parts, reproduction of replicas, etc. In this paper, two different non-contact reverse engineering scanning systems were utilized for 3D data acquisition of a cultural heritage artefact. The digital data acquisition and processing procedures of the scanned geometry have been illustrated and compared to evaluate the performance of both systems in terms of data acquisition time, processing time, reconstruction precision and final model quality. Finally, additive manufacturing technologies were applied to reconstruct a down scaled copy of the artefact.
... (b) The support of 3D models to investigate size, shape and proportions for comparative examinations among artefacts, or for research on the current spatial setting or on the original one, intending to relocate the objects at least virtually [2,3]. The advantage given by 3D remains in the subsequent stage of dissemination of the results, since its communicative potential exceeds any other textual or graphical depiction's ones; ...
This paper contributes to depict the current pattern of applications of digital 3D models for professional research and practice, and for broader dissemination of cultural heritage. Passing from a general review to the illustration of the background project, named MUSINT, the authors underline the objectives. The present case study primarily aims to share information about valuable archaeological collections which have little visibility. To enhance the project's contents, which include a whole set of different artifacts, the authors have reproduced high resolution, faithful and measurable digital models on one side, and on the other, lower resolution and geometrically simplified models are yet completed and very close to reality. The former are meant to implement a scholars' archive for further scientific activity. The latter to provide content for virtual exhibitions on the Web or on stand-alone interfaces situated in the actual physical museum spaces. The data acquisition and post-processing methods which have been tested and chosen are here briefly described. Hence, the authors then give an account of the most recurrent problematic issues of the established work-flow and how they should be solved. Touched instances are the delicate placing of the artifacts, which must be digitized, in relation to the triangulation-based laser scanner's functionality, the refining operations in order to build a coherent single polygon mesh, the most effective ways to deal with unavoidable missing parts or defected textures in the generated model and so on.
... In addition to destroying cultural artifacts as part of a campaign of religious supremacy, terrorist groups publicize the destruction of cultural property to garner international attention. The wanton destruction of the giant statues of Buddha However, the recognition gained was undeniable and continues by virtue of initiatives to plan reconstruction of at least one of the statues 81 and through controversy over conservation versus reconstruction. 82 Destruction of historic monuments and looting of antiquities during the Iraq War expanded the overall political significance of cultural property. ...
By examining the historically progressive role of cultural property in terrorism and political violence, this paper reveals the evolving significance of art to international security. Over the past two centuries, abuse of antiquities and fine art has evolved from the spoils-of-war into a medium for conducting terrorism which strives to erase the cultural heritage of ‘the other’. In contrast to wartime destruction and plunder which date back millennia, the growth of the art market over the past fifty years has created opportunities for novel abuses of cultural property. Since World War II, maturing international awareness has recognized the threat which armed conflict and looting pose to cultural property, but in parallel, art trafficking and the politics of cultural property have become tools for transnational organized crime and terrorist groups. The resulting unique intersection of issues in art, politics and counterterrorism forms the basis for a new field - cultural security. After an assessment of topical security threats which suggest the need for such a field, the paper concludes by speculating on international-security risks precipitating from antiquities trafficking and collecting.
... A virtual reconstruction is based on archived metric and non-metric images, using photogrammetric techniques. For a series of detailed publications on this project, see Grün et al., (2002aGrün et al., ( , 2002bGrün et al., ( , 2003aGrün et al., ( , 2003bGrün et al., ( , 2003cGrün et al., ( , 2003dGrün et al., ( , 2004, Grün and Remondino (2005), Remondino (2004). Patias -18 ...
... The variety of techniques available and level of expertise is such that 3D reconstructions and feature measurements are done on heterogeneous sources of images. For instance, Gruen et al. 2003 report the results of their photogrammetric work on the Great Buddha of Bamiyan. The authors performed a computer reconstruction of the statue, which served as basis for a physical miniature replica. ...
In last decade, we have witnessed an increased number of publications related to systems that combine laser scanning and closerange photogrammetry technologies in order to address the challenges posed by application fields as diverse as industrial, automotive, space exploration and cultural heritage to name a few. The need to integrate those technologies is driven by resolution, accuracy, speed and operational requirements, which can be optimized using general techniques developed in the area of multisensor and information fusion theory. This paper addresses an aspect critical to multi-sensor and information fusion, i.e., the estimation of systems uncertainties. The understanding of the basic theory and best practices associated to laser range scanners, digital photogrammetry, processing, modelling are in fact fundamental to fulfilling the requirements listed above in an optimal way. In particular, two categories of applications are covered, i.e., information augmentation and uncertainty management. Results from both space exploration and cultural heritage applications are shown. Au cours de la dernière décennie, nous avons été témoins de la publication d'un nombre croissant de documents traitant de systèmes qui marient le balayage laser et la photogrammétrie à courte portée pour relever les défis posés dans des domaines d'application aussi variés que l'industrie, l'automobile, l'exploration de l'espace et le patrimoine culturel, pour n'en nommer que quelques-uns. La nécessité d'intégrer ces technologies est dictée par les exigences en matière de résolution, de précision et de vitesse et les besoins opérationnels, auxquels il est possible de répondre au moyen de l'optimisation de techniques générales découlant de la théorie de la fusion de l'information et de multiples capteurs. Le présent document porte sur un aspect essentiel de cette théorie, soit l'estimation des incertitudes des systèmes. En fait, il est essentiel de comprendre la théorie fondamentale et les meilleures pratiques associées aux dispositifs de balayage laser, à la photogrammétrie numérique, au traitement et à la modélisation si l'on veut satisfaire aux exigences précitées de façon optimale. Nous traiterons en particulier de deux catégories d'applications : l'augmentation de l'information et la gestion de l'incertitude. Les résultats obtenus d'applications dans les domaines de l'exploration de l'espace et du patrimoine culturel sont donnés.
... Unfortunately having the ability to place retro-reflective targets on the imaged object is time consuming and is not always an option. For example Gruen et al. (2003) had to reconstruct the destroyed Buddhas of Bamiyan valley using archival images. ...
Tangible cultural heritage has provided visually appealing material for those researching in computer graphics, computational geometry, and interactive techniques. However, experiments were initially of more benefit to computer scientists as tests for their novel techniques than of any practical benefit to cultural-heritage professionals. Recently, however, tools have matured considerably, and technology is now enabling novel applications for documenting and preserving tangible cultural heritage and is continuing to inspire computer graphics researchers. Nevertheless, there's still a long way to go.
The paper focuses on the use of heterogeneous visual data sources in order to support the analysis of three-dimensional dynamic movement of a flexible structure subjected to an earthquake ground motion during a shake table experiment. During a shake table experiment, a great amount of data is gathered including visual recordings. In most experiments, visual information is taken without any specific analysis purpose: amateur's pictures, video from a local TV station, analog videotapes. In fact, those sources might be meaningful and could be used for subsequent spatial analysis. The use of photogrammetric techniques is illustrated in the paper by performing a post-experiment analysis on analog videotapes that were recorded during a shake table testing of a full-scale woodframe house. Le document porte sur l'utilisation de sources hétérogènes de données visuelles à l'appui de l'analyse du mouvement dynamique en trois dimensions d'une structure flexible soumise à un mouvement sismique durant une expérience faisant appel à une table de vibration. Durant ce type d'expérience, on rassemble une grande quantité de données, y compris des enregistrements visuels. Dans la plupart des expériences, on prend de l'information visuelle, comme des photographies d'amateur, un enregistrement vidéo d'une station locale de télévision ou des bandes magnétoscopiques analogiques, sans fin précise d'analyse. En fait, ces sources pourraient être significatives et servir à une analyse spatiale subséquente. L'utilisation de techniques de photogrammétrie est illustrée dans le document par la conduite d'une analyse (postérieure à une expérience) de bandes magnétoscopiques analogiques enregistrées durant la conduite d'un essai sur une maison à ossature de bois en grandeur réelle au moyen d'une table de vibration.
