EG1999
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Item Contour Extraction of Watermarks in Old Manuscripts(Eurographics Association, 1999) Wenger, Emanuel; Karnaukhov, Victor N.; Haidinger, AloisThe comparison of watermarks in old paper is the major technique for dating undated medieval manuscripts. The extraction of watermarks as contours is the crucial task in digitalization and building a watermark database. In this paper the method of object delineation by active curves (snakes) is modified and applied to the contour tracing and skeletonization of watermarks.Item Better Pasting Via Quasi-Interpolation(Eurographics Association, 1999) Mann, Stephen; Conrad, BlairIn this poster, we show our latest work on surface pasting, a hierarchical modeling technique. In surface pasting, we attach a feature surface to a base surface using an approximation technique. While we can use knot insertion on the feature to get the approximation to any level of tolerance, knot insertion increases the size of the representation of the feature. The work we present in this poster shows how we use quasi-interpolation to improve the approximation, allowing us to use smaller representations of our features.Item 3D virtual facial reconstruction and visualization of ancient Egyptian mummies using spiral CT data(Eurographics Association, 1999) Attardi, Giuseppe; Betro, Marilina; Forte, Maurizio; Gori, Roberto; Guidazzoli, Antonella; Imboden, Silvano; Mallegni, FrancescoThe problem of rebuilding a face from human remains has been, until now, especially relevant in the ambit of forensic sciences, where it is obviously oriented toward the identification of otherwise unrecognizable corpses; but its potential interest to archaeologists and anthropologists is not negligible. We present here the preliminary results of a joint research among the University of Pisa, the Visualisation Laboratory of CINECA and the CNR-ITABC (Institute of Technologies Applied to Cultural Heritage, National Research Council, Rome) whose aim is reconstructing, through Spiral Computed Tomography data and virtual modelling techniques (in our case with VTK software), 3-D models of the possible physiognomy of ancient egyptian mummies. This work is carried out through a multidisciplinary approach, involving different competences: image processing, anthropology, egyptology, computing archaeology. Main project tasks are: 1. anthropological and egyptological analysis of the head; 2. spiral CT of the head; 3. reconstruction of a 3-D model of the skull generated from CT data processing; 4. reconstruction of soft tissues; 5. application of textures fitting the somatic features.Item Psycho-social Happenings in Mediated Environments(Eurographics Association, 1999) Knipp, TammyOne of the virtues of our changing times is that new media has challenged us to rethink and re-examine our basic presumptions about reality and the reality that is virtually perceived. From the perspective of an elec - tronic-media artist, I present a body of work (CASE STUDIES) of performative-like installations comprised of 3-D structures integrating video imagery with the reality of the physical, psychological, virtual, and social worlds. These structures are instigators for enticing “social happenings” whereby participants and viewers become subjects from an observational perspective, providing a simulated clinical “case study.” Raising issues of belief and perceptions of trust in the constructs of mediated environments, the demarcation between virtual risk and real risk (virtual reality and reality) breaks down.Item Books and Devices from the Old -Their Renaissance in Computer Graphics(Eurographics Association, 1999) Eberhardt, Bernd; Gürcay, Hasmet; Hanisch, Frank; Hüttner, Tobias; Licht, Oliver; Nill, BenjaminIn the following we present three of our institute’s activities concerning cultural heritage. First we present a reconstruction of the Antikythera Mechanism, which is the world’s oldest calculator of astronomical purpose. The implementation extensively uses engines and sensors from the OpenInventor Graphics Library. This is a particularly interesting example of a delicate object which cannot be exhibited (without the use of a virtual Computer Graphics model) since it is too valuable and delicate. Secondly we illustrate the use of Computer Graphics to make valuable medieval books available to the public. A new texture mapping approach, allows the bilinear interpolation of texture coordinates on an arbitrary triangle mesh. This approach uses projective texture mapping and can therefore utilize the hardware of modern graphic workstations. Lastly we present an application of modern 3D Computer Graphics in the field of reconstructing ancient scientific instruments. The first-four-species calculator of Wilhelm Schickard is made accessible to the public in the World Wide Web using Java3D. All three examples illustrate the use of latest technology to model ancient books or devices.Item Tutorial 9 - Visibility(Eurographics Association, 1999) Chrysanthou, Yiorgos L.; Cohen-Or, Daniel; Fibich, Gadi; Halperin, Dan; Zadicario, Eyal; Lev-Yehudi, Shuly; Bartz, Dirk; Meißner, Michael; Hüttner, Tobias; Hüttner, Tobias; Bittner, Jiri; Havran, Vlastimil; Slavik, Pavel; Klosowski, James T.; Silva, Claudio T.The focus of this tutorial is a study of the techniques for solving visibility problems in virtual walkthroughs. The term walkthrough is referring not only to models of architectural models but rather to any large complex model, where the focus is on viewing and rendering the model. The tutorial touches on several applications such as fast visible surface determination, selection of relevant model sections to be transmitted on a client-server system, as well as improving image quality by shading algorithms.Item Interfacing Cultural Heritage(Eurographics Association, 1999) Fleischmann, Monika; Strauss, Wolfgang; Yelistratov, VladimirIn this paper we describe briefly intuitive physical interface called “Virtual Balance”, present recent modifications and give the most impressive example of its use for navigation in and exploration of reconstructed models of ancient cities. One can imagine that example as a fly on a magic carpet in the ancient cities.Item Towards Spatial Specification of Interactive System(Eurographics Association, 1999) Rodriguez, M. L.; Gea, M.; Gutiérrez, F. L.Modern interactive systems are oriented towards information management in a graphical environment. Formal specification techniques [1] help designers to describe systems, focusing on the relevant aspects of the interaction model. We analyse here a new way of describing the specifications of a directmanipulation system and we propose an extension of this concept to cover the specifications of a system based on spatial relationships.Item Virtual Reconstruction of Medieval Architecture(Eurographics Association, 1999) Masuch, M.; Freudenberg, B.; Ludowici, B.; Kreiker, S.; Strothotte, T.We describe the reconstruction of a medieval building as an example of how the use of 3D computer graphics can facilitate the reconstruction of an ancient site. We suggest that different stages of a virtual reconstruction imply the use of different rendering techniques, as the style of visualization has a significant impact on both the reconstruction process and the presentation to non-expert viewers.Item 3D laser scanning numerical surface definition and fast prototyping of the Basel Bronze Head(Eurographics Association, 1999) Accardo, Giorgio; Scarpetta, MassimilianoStarting from the experiences and results deriving from the cooperation between the Istituto Centrale del Restauro, Fox Bit srl and certain academic institutions, a study is presented which is aimed at using and adapting reverse engineering (RE) and fast prototyping (FR) industrial techniques to cultural property conservation.Item A Study of Automatic Program Production Using TVML(Eurographics Association, 1999) Douke, Mamoru; Makino, Eiji; Hayashi, MasakiThis paper describes a method to create TV programs automatically using TVML(TV program Making Language). TVML is a scripting language that we have developed for generating TV programs by computer. In this paper, we focus on automatic news program creation. We define XML tags for describing contents of a news program, and presentation data for creating the program by given XML file. We have also developed an automatic news program creation software based on the idea.Item Tutorial 2 - Level-of-Detail in Surface and Volume Modeling(Eurographics Association, 1999) De Floriani, Leila; Puppo, Enrico; Cignoni, Paolo; Scopigno, Roberto-Item Schock in the ear: sound and new media art(Eurographics Association, 1999) Neumark, NorieNew media art generally fails to engage with the imaginative and artistic possibilities and particularities of sound. Shock in the Ear is a sound -centred experimental art CDROM which explores shock -- from culture shock to electric shock and reverberating beyond into shock aesthetics.Item Perceptual Principles and Computer Graphics(Eurographics Association, 1999) May, J.Until comparatively recently, the major problems in computer display technology were caused by the difficulty of making anything recognisable at all. Eighty character-width displays, with eight or nine brilliant green lines per character, slow to respond and slow to decay, somehow enabled people to use their vast new computers with their kilobytes of memory. The pace of change should really astonish us, as we contemplate flat, bright and crisp LCD screens that require separate graphics processors and megabytes of video memory chips just to display our favourite desktop images. It now seems possible for our technological artefacts to display almost anything in as much detail as we would like, whether from a high resolution photographic image or, via skilfully implemented algorithms, by photorealistic rendering from data. In the course of this rapid development, the major problems have themselves changed: now we must ask ourselves what it means for our displays to be recognisable, and what is it in the display that needs to be recognised?Item The Norwich Virtual City Project(Eurographics Association, 1999) Arnold, D. B.; Day, A. M.This paper describes the early work on implementing a visitor attraction based on the heritage of the Norwich area. The project has been in planning for about three years, but has only just been funded and is due to open in 2001. The paper reviews the background to the project and the city, and considers the expected benefits of the venture. The range of data sources are then reviewed and areas are highlighted where computer science research needs to progress to maximise benefits. The paper then reviews progress to date on the project.Item Fast Distance Field Interpolation for Reconstruction of Surfaces from Contours(Eurographics Association, 1999) Klein, Reinhard; Schilling, AndreasOne simple and robust way to get a reconstruction of surfaces from a given contour stack dealing well with branching and other problems which are generally difficult to solve is based on the well known MC-algorithm. To overcome the staircase artefacts produced by the MC-algorithm Jones et. al. 3 proposed to use a distance field interpolation between the slices and to run the MC-algorithm on this distance field. The main problem of this approach is the distance field computation as it is very time consuming especially if high resolution grids (e.g. 10241024 are used. Therefore, in the original algorithm the resolution of the chosen grid is much less than the resolution of the given contour sacrificing accuracy of the resulting surface. Especially in medical applications this is not accepted by the doctors. In this paper we introduce a new method for the computation of the discrete distance field, which is a breaktrough in terms of speed and accuracy. This new method allows us to reconstruct surfaces from contour stacks with guaranteed accuracy in reasonable time. Several examples show the power of this approach.Item The Danteum(Eurographics Association, 1999) Nagakura, TakehikoThe Danteum was a building designed for Rome in 1938 by two eminent Italian architects, Giuseppe Terragni and Pietro Lingeri. Due to the defeat of their client, Mussolini, in WW II, the project was never realized and became one of the best known unbuilt modern projects. Through the use of advanced computer graphics technology, an attempt has been made to simulate a walk-through experience of light and materials inside this unbuilt monument. This animated representation revealed two of the important spatial characters embedded in the design of this building: a constant oscillation of dark and light as well as that of closed and open.Item Visible Surface Reconstruction with Accurate Localization of Object Boundaries(Eurographics Association, 1999) March, Riccardo; Pedersini, FedericoAn important problem in 3D reconstruction from multiple perspective views is the accurate recovery of surfaces near the discontinuities (object boundaries and creases). A common limitation of many techniques based on regularization methods is the poor quality of the results near the surface discontinuities. In this paper, we present a reconstruction method that is able to perform the surface recovery with an accurate preservation and localization of the discontinuities. The method is based on an iterative optimization algorithm. Experimental results using both synthetic and real data are presented for proving the effectiveness of the proposed approachItem On Time-Varying Flow Fields: a streakline-based visualization method(Eurographics Association, 1999) Sanna, Andrea; Montrucchio, Bartolomeo; Arina, RenzoThe visualization of unsteady flows is an attractive field of research and texture-based techniques seem to provide satisfactory results. In this paper we propose a texture-based method which follows streaklines in order to produce an effective visualization of time-dependent phenomena. Our approach allows to overcome the lack of temporal coherence due to instantaneous methods which depict each frame of an animation without considering the temporal correlation with the previous time steps.Item A VR based safety training in a petroleum refinery(Eurographics Association, 1999) Haller, Michael; Holm, Roland; Volkert, Jens; Wagner, RolandWe present the prototype omVR, which is a Virtual Reality based safety training system in a petroleum refinery. It provides an advanced technique for personnel safety training and allows users to navigate through the training setup and interact with parts of the refinery. By using a head mounted display a high degree of immersion is achieved. omVR is the implementation of a training scenario, which is too dangerous, difficult, or expensive to be performed in real life. In our system the trainer has the possibility to control the scenario from a remote trainer module which communicates with the VR simulation program.