Cyber City Algorithm for Central Europe

Andrej Ferko
ICG TU Graz

1 Introduction

This year is the 30th anniversary of signing the World Heritage convention (1972). Currently, there are 721 cultural and natural sites selected to global UNESCO's World Cultural and Natural Heritage List (Appendix 1). Seven of them are provided as the Virtual Tours at the UNESCO web page (Appendix 2) using the QTVR (QuickTimeVR) panorama movie technology. None of them comes from Central Europe!
	In the Central Europe, there are 30 (or 31) unique and recognized sites in Austria, Czech Republic, Hungary, Slovakia, and Slovenia - within the former Austro-Hungarian area. Sorry to say, this European added value is not added to the Internet community, except some fractions in the tourism-oriented web pages, mixed together with other information, often of different nature or focus. That is why we propose to start the systematic reconstruction of them as a specialized whole – Central Europe Cultural and Natural Heritage. 
	Some of the other sites or objects will be very probably included into the top values list – e. g. the Maribor (Slovenia) Water tower and the oldest living vine (more than 400 years old), or the Museum of clock in Bratislava (Slovakia).
	The UNESCO recognized historical city centers represent too much data – e. g. Prague or Graz Historic Centers. Thereafter, it is necessary to focus on some jewel parts of them first. Our initial reduction and selection idea is cultural crossroad-city verticals – towers and wells – embedded into an old city model (lower precision that will be improved later).
	Our intention is twofold. We intend to reconstruct, preserve and present the top values of the past. In addition, we will provide the people in Central Europe and Internet global village with the well-working cybercities for their future practical life.  In other words, we shall bridge the best from the past with the prospective future using the hi-tech, as envisioned in EU strategic goals.
	In the following, we will discuss the tradeoff between cultural priorities versus feasible workflow, and the methodology of preservation of cultural heritage and the complex algorithm for creating cyber cities. The strategic mission is – besides introducing the, so to say, Virtual Heart of Europe - to establish in the heart of Europe, in Central Europe, the network of EU centers of excellence (COE) for the rising knowledge based economy. The mission can be decomposed into several goals – human resources strategy, clever initialization of the work maximizing the effect and minimizing the investments, technology innovations foreseen, and a future work. 

2 Human Resources Development Strategy

We recognize three layers of human education and preparation for the future. The public opinion is very important. On the other hand, it cannot be very specialized in technology. The media impact of the cultural heritage and cyber cities initiative will serve for attracting talents from high schools for this way of specialization, too. The rising knowledge based economy will require a new creative competition for Cyber Europe, as a future semantic web branch of EuroPrix, national competitions for young creative authors of virtual cities and architectural values. It will be both useful and important to educate IT journalists and broadcast the appropriate educational TV series.
The application of semantic web, and in particular cyber city creation, should enrich the study programs. The individual study forms suite well for gifted students - seminar projects, diploma thesis, paid student positions in the research teams, and – last but not least – the specialized summer schools for beginners and advanced authors. 
Third, the research and development should address the future needs, cope with particular problems etc. The centers of excellence are not possible without having the layers – the public opinion support, the new generation of IT authors and users, and the cutting edge technology prospect. The current network of local conferences and seminars in the field is compiled in Appendix 3. 

3 Crossroad-City Verticals – Towers and Wells

This paragraph is based mainly on an influential book on Heidegger-phenomenology of architecture - Genius Loci  by Christian Norberg-Schulz (we cite the Czech translation). The book came in the time of disgusting from modern architecture (1980s). Author provided the deeper (phenomenologic) understanding of genius loci or spiritus loci.  This ancient (Latin) notion denotes the local spirit of the place. Pre-christian people believed that each place -  house or nameable outdoor location - has some spiritual being associated. Today, the unique harmony of the given interior or exterior is meant by this. In contrast to artificially created uniform urban solutions, the spiritus loci arises - in a valuable place - from the dialogue of multiple cultural and historical influences. This is explicitly stated for Graz City Center in the UNESCO record: „The historic centre of the city of Graz reflects artistic and architectural movements originating from the Germanic region, the Balkans, and the Mediterranean, for which it served as a crossroads for centuries. The greatest architects and artists of these different regions expressed themselves forcefully here and thus created brilliant syntheses. … The urban complex forming the historic centre of the city of Graz is an exceptional example of a harmonious integration of architectural styles from successive periods. Each age is represented by typical buildings, which are often masterpieces. The urban physiognomy  faithfully tells the story of its historic development. … Graz is a particularly fine example of the living heritage of a central European urban complex that was under Habsburg rule for many centuries. The old city is a harmonious blend of the architectural styles and artistic movements that have succeeded each other since the Middle Ages, together with cultural influences from the neighbouring regions.“  We have highlighted the sentence exactly in the spirit of the book recalled. Moreover, the quotation reflects the added value of cultural crossroad. The East-West and South-North diversity spanned not only the market crossroads - amber way and the Danube river exchange directions - but also the dialogue of important styles.
The city has, among others (squares, riversides, streets, quaters), the city verticals, given by towers, memorials, silhouettes, rivers and wells (old water sources). The oldest known ancient algorithm for founding a new city, as described by B. Bogdanovic, has been preserved in Latin books (Vitruv, Cicero). The founders of Roma were Etruscans – “engineers” invited by the rural Romans who had no knowledge in the field. The Etruscans computed using some religion oraculum – and the practical experience - the city location, ploughed the city border around, erected the city tower or church to transcend the city to the sky and – nearby – they have digged a mundus. The mundus was not necessarily the well. It was the root of the city, transcending the city downwards, into the earth and into the depth. (One can see in erecting and rooting the male and female principles.) The Etruscan language, being isolated from Indo-European languages, has been not understood (and only one book – Linen Book, Liber Linteus – exists, written on the cloth, see Appendix 4 for description and images). Despite the fact that we do not know the language we know we have two fundamental Etruscan words in the international language – urbs (the city) and mundus (the world, the meaning was changed by the Latin users). 
Thus, the city verticals today both resemble the oldest known urbanization algorithm and define the vertical extent of the place or city. They are important because they give us physical and mental borders. They are very important because they are the prominent storytellers. “The urban physiognomy faithfully tells the story of its historic development” – not only in Graz. 
From practical point of view – the city verticals can be reconstructed more easily than the large city blocks what is given simply by comparing the data volumes. In Graz, this is not completely true because the historic well has so highly complex iron-made medieval decoration lattices that even the measurement will be a very challenging task. For comparison, a medium size city such as Graz with 40 000 buildings and an even larger number of trees, the required data set consists of about 250 terabytes of data. On the other hand, there is the first paper published recently – towards automatic modeling of monuments and towers by Sabry El-Hakim (June 2002). Prague, Maribor, and Graz have famous towers. Prague itself has the large chapter in the genius loci book. Maribor water tower is a unique building. Maribor had the Drava river water used as one part of the fortification and the water tower served as a unique technologic node. Grazer Clock Tower has the globally unique architectonic solution. By the way, this tower image is used to represent the complete Austrian cultural heritage at the Austrian tourist page.
Fortifications of Bratislava and Graz were destructed by Napoleon. Bonaparte, French bloody dictator, did it in early 19th century. Being located at the hills, both fortifications had the water supply problem in the age of Osman aggression when the hunger-out and thirst-out were strong weapons. Both famous wells were built in the hard rocky terrain and both share the nice stories and unbelievable legends – with Turkish prisoners in Graz and with Maria Theresa in Bratislava. And, there are other wells, out of the hills – in the downtown. 
Besides the city verticals, we plan to make virtual the top attractions in each cultural center. They are the Number Ones in tourist guides and a strong European added value, as well. The globally unique objects with strong European added value can be scanned, modeled, and reconstructed pretty well. The final nomination depends on the ongoing research. For instance, there is a travelling forest in Austria, the rock avalanche with the trees falling on a small village, which can eventually grow up to be the top quality global tourist attraction soon. Again, this unique phenomenon is studied at TU Graz. 
For the long term consideration, there is the possibility to combine – in addition to cities - three famous caves for reconstruction, the Slovenian Skocjan caves and the Slovakian Domica Cave, which is – together with the Hungarian cave Baradla - the part of Hungaro-Slovakian World Heritage item. (For the long term perspective there will be the need to have partners in each country… in particular this means the prominent Hungarian graphics group headed by Laszlo Szirmay-Kalos and – eventually – the group from Croatia headed by Zeljka Mihaljovic.).
„The Domica Cave is one of the most spectacular show caves in the whole of Slovakia. Situated right on the Hungarian border, south of Roznava, Domica is famous for its cascading pools and onion-shaped stalactites. However, for most the highlight of any trip will either be the boat ride on the underground lake, or the flying bats (there are approximately 1500 of them, including 11 different species).“  The idea of reconstructing caves, especially the ice ones or previously inhabited caves has been proposed by Alan Chalmers, one of the founders of virtual archaeology. They are for sure unique and they belong both to natural and cultural heritage.
Our conclusion for this part of general project decision can be summarized in the following steps. We start with the UNESCO's World Cultural and Natural Heritage List to identify the global priorities in cultural and natural values in Central Europe. As there are four capable research teams to run the initial phase of the strategic mission, we have adopted the practical and pragmatic (minimum costst) restriction to start with global values in crossroad-cities Prague, Graz, Bratislava, and Maribor. Second, we select the representative city verticals and embed them into the virtual old cities, modeled at the reasonable level of precision. Third, we add some very special local rarities to preserve and publish the top quality attractions. Fourth, we will create the 3D reconstructions, models, and virtual environments. So far, the creations are static and having no inhabitants. Therefore, the creation of virtual habitat follows – navigation, exploration, and cooperation support. In general, this completes the outline. In the next paragraphs we have to cope with the methodology and technology to enable the realization of the general steps. 

4 Cyber City Algorithmisation Methodology

Creating photorealistic virtual inhabited environments from existing sensed or simulated data enables for new forms of communication and cooperation. The scientific goal is obtaining answers to particular problems in the fundamental research in methodology and technology for web oriented applications. There are multiple practical goals, see below. In the following, we discuss the methodology. 
Cyber cities are probably the best application for combining the power of computer graphics and vision methods. The modeling methods spectrum is nearly maximally employed. Cyber cities can be divided into real and fictitious ones. The difference is that the later ones are created by fantasy of the authors. Unlike that, the real cyber cities are built with controllable precision. They model existing cities (or excavations of former urban formations) for education, advertisement, tourism, telecommunications, and virtual habitat. Various cyber city applications represent the above mentioned practical goals.  Realized examples include Denver, Graz, Paris… The virtual archaeology solutions are e. g. Tenochtitlan, Sagarassos, Pompeii… Historically, the first web-published cyber city was… hosted in Amsterdam.
We will not deal with the cyber cities based on fiction. They are used for games, entertainment, socio-cultural experiments etc. Curiously enough, there was created a virtual cemetery where the visitors could establish the virtual graves of their real enemies or disliked actors and politicians. 
Creating the cybercity means to solve the inverse problem. Having no formula (model) for any real city, we have to measure the real city and reconstruct. Reconstruction (or geometric inverse problem) is the algorithmic problem of combining the results of one or more measurements of some aspect of a physical or mathematical object to obtain certain desired information about the object. Reconstruction is – methodologically - only halfway. Any cybercity is for people – it should serve as inhabited virtual environment – virtual habitat. Virtual habitat includes model, virtual society – and stories. 
The taxonomy of all inhabited virtual environments from the point of view of interactive digital storytelling gives the book by Lars Quortrup on virtual interaction. The methods for managing narrative multimedia production grow from software design (oriented to functionality) and traditional media (oriented to storytelling approach and focused to content). The quality of them includes the business and narrative quality. (Two non-specific problems are general for managing each production – the lack of communication within the production team and with the customers, and the lack of decision, when the customers are not informed enough.) The narrative is defined as the advancing of the story. The narrative premise (message, plot, sujet) is often morally oriented. The narrative structure (fabula, die Handlung in German) is the way how the narrative is built up in space and time. For each cyber city or virtual habitat there will be the need for stories. The (hi)story of the city and the (hi)story of the virtual city creation are two prominent ones. Many specialized stories based both on historical facts and urban legends will start during the creation of city verticals. 
The inhabitants of the cybercities can be divided, by Qvortrup, into six groups according to their attributes: human user, designer-in-avatar, user-in-avatar, bot, object, virtual world. This gives 21 different types of virtual interactions. Moreover, we have to distinguish between evidence and hypothesis in any cybercity virtual habitat. For example, the virtual archaeology processing pipeline combines digital elevation model with photogrammetry, antiquarian and excavation findings into the phasing and structural scenarios. This is the evidence part, where both archaeological research and computer model apply. At this point the hypothesis layer of processing starts. From structural scenarios there are derived the ritual and lighting scenarios. They were implemented in INSITE system using parallel processing and photo-realism. The interactive system enables for creating alternative hypotheses, which can be included into the database of ritual scenarios. 
Recall, that the visualization scenarios are movie-mode, tracking, interactive post-processing, and interactive steering.
Human-computer interaction (HCI) is a discipline concerned with the design, evaluation and implementation of interactive computing systems for human use and with the study of major phenomena surrounding them. Well designed HCI solutions have to address both very simple one, very beginning user and very advanced user, expert in the field, even guru. (It is possible to assume the artist user as the third alternative.)
The recent ACM computing curriculum identifies the following design issues: Choosing interaction styles and interaction techniques; HCI aspects of common widgets; HCI aspects of screen design: layout, color, fonts, labeling;  Handling human failure; Beyond simple screen design: visualization, representation, metaphor; Multi-modal interaction: graphics, sound, and haptics; 3D interaction and virtual reality.
The following are the HCI aspects of multimedia system: Categorization and architectures of information: hierarchies, hypermedia; Information retrieval and human performance; Web search; Usability of database query languages;          Graphics; Sound; HCI design of multimedia information systems; Speech recognition and natural language processing; and Information appliances and mobile computing.
HCI aspects of collaboration and communication take into account: Groupware to support specialized tasks: document preparation, multiplayer games; Asynchronous group communication: e-mail, bulletin boards; Synchronous group communication: chat rooms, conferencing; Online communities; Software characters and intelligent agents.
Virtual reality or virtual environments are defined as systems that create a real time visual/audio/haptic experience. It is worth to distinguish among five virtual realities. They are basic VR, augmented VR, projected VR, immersive VR, and Multi-user Distributed VR. Moreover, there exist overlaps in research directions like Mixed Reality. The VR languages include SuperVR, QuickTimeVR, VRML 2.0 (and MPEG-4). VRML browsers may have special JavaScript – ECMAScript and external authoring interface EAI, both ISO standardized.
We will assume only the case of one user immersed more or less in the basic VR, immersive VR or projected VR like CAVE. We have to specify four layers. 1. Image layer, 2. Geometry, surfaces, kinematics, 3. Physical layer, and 4. Behavioral layer. And, in the virtual worlds may live avatars. The user has to deal with interaction and navigation. In order to explore virtual world we require real-time graphics, and stereoscopic sight. Navigation requires tracking the positions of user’s head in 3D. The walk and wired head-tracking limit the navigation. Therefore the hand-held flying mouse is used to instruct the host computer to “fly”. Motion sickness can appear. Non-immersive or desktop VR must be navigated using totally different techniques, navigation controls. The ability of navigate without physically moving has tremendous importance for an extraordinary range of applications.  
The VR-specific interaction paradigm is outside Ziegler’s classical 3D model (representation, referencing, and punctuation dimensions) of interaction paradigms, as there is no strict border between user and system. The movement inside the workspace can be done in at least four different manners: general movement (walk), targeted movement (fly), specified coordinate movement (absolute or relative), and specified trajectory movement. 
	The spectrum of above methodologies requires frequently the time-critical rendering. This is nicely formulated by Jed Lengyel: Computer graphics and computer vision are inverse problems… Lately, there has been a meeting in the middle, and the center – the prize – is to create stunning images in real-time.
	As can be easily seen, the general methodology relevant for cybercities includes nearly all fields of contemporary computer science. That means that even the methodologic context is very complex and rich. To complete the survey we have to return to the two general design problems – lack of communication and lack of decision. They can be prevented by good competence subdivision among local teams and excellent human resources preparation in all three layers – public opinion, students and researchers. 
The competence of local teams consists from providing 1. legal access to data (including aerial photos, terrain data, other digital and pictorial material, texts, stories, maps); 2. negotiations and contacts with local partners; 3. translations into English; 4. exchange of experience and (re-)use of necessary tools; 5. others. If there will be any restrictions for the use of data or software tools given by the previous contracts by any partner they will be neglected in full extent. 
The particular research focus is given by the previous specialization of the groups. Prague group (headed by Jiri Zara ) specializes on VRML and web hosting technology recent extensions. Graz TU/VRVis group (headed by Konrad Karner) has the advanced reconstruction research. Maribor Gemma lab (headed by Borut Zalik) excels in geometric modeling and kadaster applications. Bratislava research (headed by Valent Zatko and Andrej Ferko) deals with inverse problem, user interaction and large graphic/multimedia databases. If there is another technology available we can study it and share, e. g. there is a prospective two display stereoscopic visualization of Ljubljana (Slovenia) by an industrial company. 
The super-supervisor for cyber cities is Prof. Franz W. Leberl (USA, Austria). At TU  Graz, the researchers at ICG and VRVis – key researcher is Konrad Karner - have rich experience in cyber city creation and many respected publications in international IT and academic community. In Central Europe, they have several years of experience with the most advanced project in the field – Virtual Habitat. 
This survey of relevant methodology can be obviously refined according to the methodology needs for solution of any particular technological subproblem in cyber city creation. 

5 Cyber City Technology

State of the art in the field can be characterized in a following way. Virtual environments and their public distribution are the subject of extensive research. The new forms of communication include a number of open problems.  One of EU priorities is cultural heritage protection. European research space requires the detailed research and data preparation, acquisition, processing and utilisation, both in real and synthetic data. Problematics can be divided into modeling and sharing exterier and interier scenes which differ in navigation, exploration and cooperation modes. 
Open problems in particular are data compression and communicátion (information visualization), alternatives of cooperation, improving the photorealistic displaying and humanisation of user interface. Practical goals include:1. Reduction of manual data processing. 2. Prototype solution for exterier and interier scenes. Combination of  VRML and Quicktime VR (QTVR) approach (model based rendering vs. Image – based rendering). Analyze the arising WWD: Multimedia global database (MPEG-4, XML) and dynamic portals,  ISO and W3C norms. 3. Content driven interaction, navigation and cooperation for exterier and interier. 4. Combine VRML  avatars with QTVR approach and sound and facial expressions to increase the empathy of interface for digital storytelling. 
We prefer using of free tools:  Maya PLE, AMAYA, Java, Web3D Consortium Tools... The motivation for this is that, following the Virtual Old Prague way of communication with the wide public, in the future anybody can be the author of the next virtual street or building. The volume of data for complete models cannot be processed by the project people. 
The reference book for the field – virtual habitat technology - does not exist. 

5.0 Data Sources

Photogrammetry, range images, etc.  provide information  about large point clouds  measured  in  real  world.  Another  source of pointclouds  represent  the  procedural  or  interactive  models. Procedural models  are very suitable  e. g. for  vegetation. Interactive models work well for  man-made objects. Digital terrain  model  and  aerial   photos  can  be  employed,  if available. The data acquisition can be done using photographic and non-photographic sensors (radar or laser images). 
Regardless,   the   topology   creation   consists   of preprocessing,  faces  definition,  and  triangulation. (The alternative is  to work with  point-based graphics.) Due  to the complexity of real  scenes and unsatisfactory quality of automated image understanding the bottleneck is the topology creation. Data source  managers will process and store pictorial  and textual information, moving pictures, deal with database   maintenance (data  formats  and conversions) for any data (even medical   data, multimedia, video sequences). 

5.1 Topology Creation

Unlike triangulation, preprocessing and faces definition is often done manually.   The semiautomatic approach - probabilistic relaxation - has been used in cc-modeler for fitting the surfaces  of buildings  and streets  in Zurich, Regensdorf  and Firenz  (www.geod.ethz.ch). The Virtual Old Prague  reduces the  burden of  work by  simplified streets model and by "open model" strategy (www.ms.mff.cuni.cz). The Virtual Habitat project (www.vrvis.at) started with manually extracted  roof  lines   and   improved   the   method  by sophisticated employing  of epipolar geometry. This can be further improved by increasing  number  of  samples using videosequences (M. Pollefey) or   by  trifocal and quadrifocal  tensor computations. Topology creators will use general methods, range   data   processing, optimal triangulations and special methods. The unique attribute of transparent parts has been used in 3D Murale project to manage the hypothetic layer of data. 

5.2 Level of Details for Efficient Visualization

Consequently, the multiresolution modeling, texture mapping and visualization can be completed. Textures and   multiresolution surfaces for texturing, texture manipulation and image reconstruction. Rendering and visualization finishes the model part of the processing pipeline.

5.3 User Interface Considerations and Project Steps

Once  3D  model  exists,   it  becomes  immediately  of interest to experience spatial  data. There are two possible ways -  using cheap 2D  hardware (PC platform)  or immersive virtual  and augmented  reality laboratory  environment. The immersive  user  interface  can  be  shared  directly  or by avatar(s).  User activities  can be  divided into different kinds: navigation, exploration, cooperation.
The User Interface Group will develop the avatars, behaviors, audio processing, facial  expressions, and  web   design.  The standard and experimental navigation and interaction tools will be designed and implemented.

1. Input data processing 
    - terrain model, 
    - aerial photos, 
    - simulated data for enviroments and avatars 
2. 3D modeling and rendering for WWW
   - time and data volume optimization
   - photorealistic visualization
3. Communication and cooperation tools 
    - alternative navigations, 
    - multimedia database, 
    - dynamic portal
4.  WWW experimental publishing and maintenance

Methodologic Goals:
1. Maximal automatisation of large data processing
2. Prototype solutions of virtual environment: exterier and interier one
3. Testing of interaction in navigating and cooperating modes
4. Humanisation of user interface 
     - facial experssions animation for avatars, 
     - experimental sound communication -  VRML 2.0
5. Final version presented/WWW for  particular types of application (cyber city, virtual museum, virtual distributed visualisation via internet)

5.4 Additional Functionality
Data  processing  and   model  extensions  may  require utilising of various  software tools (AutoCAD, MicroStation, ArcView,  Maya, VRML  viewers...) Therefore  the conversions among  different 3D  data formats  are necessary  (raw data, VRML, DXF, IV...). Database and data filters will be developed in the form of proprietary software tools. 
Virtual  environments  can   be easily  used   for  animation production.  The animations  give answers to  frequently asked questions and increase the speed of introductory walkthroughs  or  flyovers  for  unexperienced  beginners. They enable for off-line  presentations. No  interaction is  needed and  the benefit  of   large  scale  projection   is  available.  WWW accesibility or a standalone application intended for CD-ROM are the options in this project phase.
There are virtual environments with avatars and without avatars. Avatars, Digital Storytelling and Immersive Experiments
Obviously, project supervision and/or practical work can identify certain new sub-problems in geometric modeling, cyber city generation and maintenance. 

5.5 CULTURE 2000 Project Timetable
	Culture 2000 is the EU initiative. The deadline for submitting projects is October 15, 2002. The Cultural crossroad-city verticals – towers and wells – project workflow can be roughly divided into three parts – initial, central and final ones. Some of the working items overlap in time.  

0. Working Seminar and Intranet Opening - April 15, 2003
1. Project Detailed Technical Specification - 5/03 - 6/03
2. Hardware, Software and Network Setting Up -  5/03 - 7/03
3. Data Acquisition, Project Intranet Final Structure, Database - 6/03 - 9/03

4. Project Web Pages Design and Maintenance - 5/03 - 3/04
5. Initial Modeling and Rendering Experiments -  5/03 - 9/03
6. Topology Generation, GUI Development - 5/03 - 3/04

7. Proprietary Software Development - 6/03 - 12/03
8. Testing and Experimental Presentations -  7/03 - 12/03
9. CD Production - 1/04 - 3/04
10. Publications and Demonstrations – 4/03 - 3/04 

5.6 Related Projects
In Graz, there are the Stadtvermessungsamt projects. There are perfect technology papers published from this project team.
In Prague, there is the Virtual Old Prague project… 
In Maribor, there was the introductory study for modeling the water tower. For the lack of investment, the project finalisation is pending. This means, that the small volume project was finished, but the model of the tower needs more efforts.
In Bratislava, there are some QTVR panoramas for tourists. Two small volume local grants were submitted. On the other hand, Virtual Bratislava as a whole is under the auspices of Slovak President.

6 Conclusion 

This paper is not finished in many directions.  This vision/version focused on the content, not on giving references.

7 Acknowledgements 

Special thanks to many people. 

World Heritage/UNESCO (Appendix 1)
With 721 cultural and natural
                             sites already protected
                             worldwide, the World Heritage
                             Committee is working to make
                             sure that future generations
                             can inherit the treasures of the
                             past. And yet, most sites face a
                             variety of threats, particularly
                             in today's environement. The
                             preservation of this common
                             heritage concerns us all.
http://whc.unesco.org/nwhc/pages/home/pages/homepage.htm

Report of the the 25th Session of the World Heritage Committee, Helsinki, Finland, 11-16 December 2001 at 
http://whc.unesco.org/toc/mainf15.htm

AUSTRIA:                                                                                                 http://www.austria-tourism.at/weltkulturerbe/
  1996 Historic Centre of the City of Salzburg 
  1996 Palace and Gardens of Schönbrunn 
  1997 Hallstatt-Dachstein Salzkammergut Cultural Landscape 
  1998 Semmering Railway - http://whc.unesco.org/sites/785.htm
  1999 City of Graz – Historic Centre - http://whc.unesco.org/sites/931.htm
  2000 Wachau Cultural Landscape
  2001 Historic Centre of Vienna

AUSTRIA/HUNGARY: 
  2001 Cultural Landscape of Fertö/Neusiedlersee

CZECH REPUBLIC: 
  1992 Historic Centre of Prague 
  1992 Historic Centre of Cesky Krumlov 
  1992 Historic Centre of Telc 
  1994 Pilgrimage Church of St. John of Nepomuk at Zelena Hora 
  1995 Kutná Hora: Historical Town Centre with the Church of St Barbara and the Cathedral of Our Lady at Sedlec 
  1996 Lednice-Valtice Cultural Landscape 
  1998 Holašovice Historical Village Reservation
  1998 Gardens and Castle at Kromeríz
  1999 Litomyšl Castle 
  2000 Holy Trinity Column in Olomouc
  2001 Tugendhat Villa in Brno

HUNGARY: 
  1987 Budapest, the Banks of the Danube and the Buda Castle Quarter 
  1987 Hollokö 
  1996 Millenary Benedictine Abbey of Pannonhalma and its Natural Environment 
  1999 Hortobágy National Park 
  2000 The Pécs (Sopianae) Early Christian Cemetery

HUNGARY AND SLOVAKIA: 
  1995, 2000 Caves of Aggtelek and Slovak Karst - http://whc.unesco.org/sites/725.htm

SLOVAKIA: 
  1993 Vlkolinec - http://whc.unesco.org/sites/622.htm
  1993 Spissky Hrad and its Associated Cultural Monuments 
  1993 Banska Stiavnica - http://whc.unesco.org/sites/618.htm
  2000 Bardejov Town Conservation Reserve

SLOVENIA: 
  1988 Skocjan Caves - http://whc.unesco.org/sites/390.htm 
   2002? Partisan hospital Franja – submitted, not accepted up to now (e-mail message by Borut Zalik, zalik@uni-mb.si)

World Heritage Seven Virtual Tours/Technology (Appendix 2)
http://whc.unesco.org/nwhc/pages/home/pages/homepage.htm

1.
San Lorenzo, Panama 
El Castillo San Lorenzo El Real de Chagre/QTVR  
http://www.sanlorenzo.org.pa/touring.htm

2.
 Amsterdam, Netherlands 
 Fort near Nigtevecht is one of 45 forts and batteries in the Defence Line of Amsterdam/QTVR

3.
 Beijing, China 
 Second courtyard of the Forbidden City/QTVR

4.
 Angkor,Cambodia 
 The ancient temple of Ta Prohm/QTVR 

5.
 Historic Center of Naples, Italy 
 Founded in 470 BC by Greek settlers /QTVR

6.
 Great Pyramid of Giza, Egypt 
 Considered one of the Seven Wonders of the World /QTVR

7.
 Pompeï, Italy 
 Buried in 79 AD, the ancient city of Pompeii and its many superb wall paintings live again /QTVR

The pros and cons of QuicktimeVR movies are discussed above, in the methodologic part 4 of this paper.

Conference Calendars and Central Europe (Appendix 3)

A31 Global conference calendars: 

http://www.vrvis.at/ConfCal 
http://www.siggraph.org/calendar/table.html 
http://www.computer.org/conferences/calendar.htm 
http://www.techexpo.com/ 

A32 Central Europe local conferences, workshops & international seminars for graphics and vision 

East-West Vision 2002, no fee, fully sponsored, workshop and project festival, deadline for abstracts June 14, 2002 
http://www.icg.tu-graz.ac.at/~fraunfri/ewv02/content.htm 
Graz, Austria, September 12-13, 2002 

26th Workshop of the  AUSTRIAN ASSOCIATION FOR PATTERN RECOGNITION (AAPR), 
"Vision with Non-Traditional Sensors" 
http://www.icg.tu-graz.ac.at/oeagm2002 
Graz, Austria, September 10-11, 2002 

ALGORITMY 2002, 
http://www-kmadg.svf.stuba.sk/alg2002/ 
September 8-13, 2002, Vysoke Tatry, Northern Slovakia 

SCG´2002, SCG Kocovce, deadline May 30, 2002,  fee 15 EUR
11th Symposium on Computer Geometry 
http://www.km.sjf.stuba.sk/scg.htm 
Kocovce, West Slovakia, 9. - 11. 10. 2002,

ECI, Electronic Computers and Informatics, 
http://hornad.fei.tuke.sk/kpi/eci/main.html 
Kosice-Herlany, October 10-11th  2002,  Eastern Slovakia, 

WSCG Plzen, Czech Republic - February 2003, 2004
Winter School on Computer Graphics  
http://wscg.zcu.cz/wscg2003/wscg2003.htm, http://wscg.zcu.cz/wscg2004/wscg2004.htm 

APLIMAT 2003 Bratislava, Slovakia - February 2003 
http://www.km.sjf.stuba.sk/aplimat.html 

SCAM, April ?? 2003, Bratislava, Slovakia - for PhD students - papers published in JEE journal 
http://www.elf.stuba.sk/Katedry/KM/scam/ 

CESCG 2003 Budmerice, undergraduate student seminar, no fee, fully sponsored, 
http://www.cg.tuwien.ac.at/studentwork/CESCG/ 

SCCG 2003, Budmerice, Slovakia, April 2003 
http://www.isternet.sk/sccg/pages/welcome/welcome.html - page of SCCG 2002 

A33 Notes

- GPKO 2002 - biannual Graphics & Vision conference in Poland was not held this year (the associated MGV journal page                      http://www.ippt.gov.pl/~zkulpa/MGV/MGV.html) 
-	Workshop Conference Bridging the Gap between Eastern and Western European Multimedia Content, held May 24-26, 2002, in Salzburg, (and one year before in Budapest) will be repeated annually, probably. This is connected with the EUROPRIX competition.The  registration deadline is July 15, 2002. 
       http://www.europrix.org/europrix/europrix/timetable/Index.htm.

The Etruscan Liber Linteus (Appendix 4)
http://users.tpg.com.au/etr/etrusk/default.html
http://www.geocities.com/Athens/Thebes/5181/etrusk/default.html

„… It is a manuscript, found in Egypt on the bands of a mummy, and presently conserved in the National Museum of Zagreb (Croatia). It is also the only example of a book written on linen cloth (hence the Latin name Liber Linteus). Moreover, it is the only Etruscan book handed down to posterity. Originally it  was a scroll which was brought to Egypt for unknown reasons. It was later cut into strips used to bandage the mummy of a woman, probably during the 1st century of our era. Putting the stripes the one near the other it was possible to reconstruct a part of the original manuscript, consisting of 230 lines of text and 1200 words that can be read more or less clearly, and 100 more words that can be reconstructed from the context with a high degree of certainty. The manuscript is a kind of religious calendar containing the indication of where and when the ceremonies had to take place, the concerned gods, the offerings to be made, etc.“ 

Fig. A1. Etruscan alphabet (derived from Greece one).

Fig. A2. Etruscan sculpture of a linen book. The complete book… and a fragment visible in infrared light. 

The cross-road nature of Central Europe is currently emphasized by the less-known fact that the Liber Linteus is in the National Museum of Zagreb (Croatia) now and that this is another example of a global uniqueness, available in the heart of Europe.