by a number of frescoes on the walls. One of them, Christ and 
the Annunciation, is dated at 959 c.e. and is signed by 
Theophylact. These facts make this Crypt an important heritage 
site. During the course of history, the floor was lowered in 
order to make room for a Baroque altar and three pillars replace 
one that collapsed in the 18 th century. Figure 10 presents a view 
of the texture-mapped model of the Crypt from a vantage point 
that is not physically possible. In fact, the view is taken outside 
the Crypt with the texture information map applied on the back 
of the walls. As an example to illustrate a virtual restoration on 
textual information, Figure 1 la shows the current state of some 
of the writings on the so-called Theophylact group and Figure 
lib presents the enhanced version with some modifications 
brought to the texture image using the text presented by 
(Fonseca et al., 1979). These snap shots come from the model. 
5. CONCLUSION 
Virtual and virtualized environments offer the possibility to 
expand our abilities in planning, creating and experiencing new 
surroundings, e.g. virtual tourism on sites that have been closed 
to the general public or sites not popular as some may want. 
The resulting visual simulation aims at an exact representation 
of the real world allowing for photo-realistic rendering, 
telepresence, and intuitive information queries. People have 
been trying to improve the sense of realism by using models 
generated by sensors. If the only goal is the generation of 
photo-realistic images for visualization, then purely image- 
based rendering techniques offer a general solution. However, 
if the goal is to analyze the work, to preserve and share a record 
of their geometry and appearance, then explicit shape 
information must be acquired and stored in an adequate 
representation that also includes some form of appearance 
modeling. 
The potential of modeling as-built reality for heritage 
applications for such applications as virtual restoration, or as an 
input to virtualized reality tours was shown with a Byzantine 
Crypt. A high degree of realism can be attained by those 
techniques and the context in which the artefacts were 
discovered or were used can be recreated. Real world 
acquisition and modeling is now possible. Technological 
advances are such that difficulties are more of a logistical 
nature than technological per se. Many techniques exist to 
digitize small objects with both a high-resolution 3D surface 
and a view independent surface texture with perfect registration 
between them. Models of large objects, structures and 
environments are possible but as demonstrated here require the 
combination a number of techniques. Many papers in the 
literature explore both modeling and texture mapping onto 
dense 3D models but the results are not necessarily accessible 
to everyone interested in applying this technology. The 
problem we addressed in this paper is the creation of tools and 
methods that work with commercial devices and software. 
6. ACKNOWLEDGEMENTS 
Contributors: E. Bandiera, F. Bergamo, M.C. Catamo, Sac. G. 
Colavero, D. Lucarella, R. Ingrosso, A. Marra, F. Melcame, S. 
Nuccio, P. Pulii, A. Van Den Troost, U. Parrini, M. Biliotti, C. 
Sempi, V. Blasi, R. De Rinaldis and M. L. Blasi. Co-financing 
was provided by the Ministero dell'Istruzione, dell'Università e 
della Ricerca and the European Union (F.E.S.R.) for initiative 
18 of the Piano Coordinato delle Università di Catania e 
Lecce. 
1 . REFERENCES 
Bandiera E. 1980. Carpignano Salentino: Centro, Frazione, 
Casali, Ed. Lorenzo Capone, Cavallino. 
Baribeau, R., Rioux, M., and Godin, G. 1992. Color reflectance 
modeling using a polychromatic laser range sensor, IEEE 
Transactions on Pattern Analysis and Machine Intelligence, 
14(2), pp. 263-269. 
Bemardini, F., Martin, I.M., and Rushmeier H. 2001. High- 
quality texture reconstruction from multiple scans, IEEE 
Transactions on Visualization and Computer Graphics, 7(4), 
pp. 318-332. 
Debevec, P. E., Taylor, C. J. and Malik, J. 1996. Modeling and 
rendering architecture from photographs: A hybrid geometry- 
based and image-based approach. In Proc. of ACM Siggraph 
1996, ACM Press/ACM SIGGRAPH, New York. E. Fiume, 
Ed., Computer Graphics Proc., Annual Conf. Series, ACM. 
El-Hakim S.F. 2001. Three-dimensional modeling of complex 
environments. SPIE Proceedings vol. 4309, Videometrics and 
Opt. Methods for 3D Shape Measurement, San Jose, Jan 20- 
26. 
El-Hakim S.F., Brenner C., and Roth G. 1998. A multi-sensor 
approach to creating accurate virtual environments, ISPRS 
Journal of Photogrammetry & Remote Sensing, 53, pp. 379- 
391. 
Fonseca, C.D., Bruno, A.R., Ingrosso, V., and Marotta, A. 
1979. Gli insediamenti rupestri medioevali nel Basso Salento, 
Ed. Congedo, Galatina, p. 63. 
Neugebauer P.J. and Klein K. 1999. Texturing 3D Models of 
Real World Objects from Multiple Unregistered 
Photographic Views, In Eurographics ’99 Conference 
proceedings, pp. 245-256. 
Sequiera, V., Ng, K., Wolfart, E., Goncalves, J. and Hogg, D. 
1999. Automated reconstruction of 3D models from real 
environments. ISPRS Journal of Photogrammetry & Remote 
Sensing, 54, pp. 1-22. 
Soucy, M. and Laurendeau, D. 1995. A General Surface 
Approach to the Integration of a Set of Range Views, In IEEE 
PAMI, 17(4), pp. 344-358. 
Soucy, M. Godin, G. Baribeau, R. Blais, F. and Rioux, M. 
1996a. Sensors and algorithms for the construction of digital 
3-D colour models of real objects, Proc. of the IEEE ICIP, 
Lausanne, Suisse. September 16-19, Vol. II. pp. 409-412. 
Soucy, M., Godin, G., and Rioux, M. 1996b. A texture 
mapping approach for the compression of colored 3D 
triangulations, The Visual Computer, 12, pp. 503-514. 
Stamos I. and Allen P.K. 2000. 3-D model construction using 
range and image data. Proceedings IEEE Conf on Computer 
Vision and Pattern Recognition. CVPR 2000, 1, pp. 531-536. 
Triggs, W., McLauchlan, P., Hartley, R., and Fitzgibbon, A. 
2000. Bundle Adjustment for Structure from Motion, Vision 
Algorithms: Theory and Practice, Springer-Verlag. 
SIBA Web Site: http://siba2.unile.it, http://siba3.unile.it/ctle/ 
Weinhaus M. and Devarjan V. 1997. Texture mapping 3D 
models of real-world scenes, ACM Computing Survey, 29(4), 
pp. 325-365. 
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