Papers & Publications:
Conference Paper: Photo-Realistic 3D Reconstruction of Castles with Multiple-Sources Image-Based Techniques
Abstract: Digitally reconstructing a large and complex heritage site, particularly medieval castles, for documentation, research, and virtual reality simulation is a challenging task. Castles by design contain many lines of defense such as inner and outer rings of walls and are often located on high grounds, surrounded by water or forests. They also have protective entrances, towers, courtyards, and a mixture of large complex buildings. Although laser scanners have many advantages, they may be impractical for reconstructing an entire castle. They are not portable or fast enough and can generate a huge amount of data that is difficult to register and visualize in real time. Therefore, we set out to fully explore the potential of only image-based techniques for modeling castles. We captured aerial and ground-based images and used existing floor plans and limited surveying, which compelled us to develop a technique to assemble and integrate models made from different data sets. We will discuss the issues and problems associated with modeling castles, give details of our approach, and present and evaluate the results of modeling the Stenico castle in Trentino, Italy, as a test-bed.
Presented at XXth ISPRS (International Society for Photogrammetry and Remote Sensing) Congress in Istanbul, July 2004. In collaboration with L. Gonzo, S. El-Hakim, M. Picard, and S. Girardi.
Animated Film: Aboriginal Rock Art in the Baiame Cave
Abstract: coming soon...
Presented with conference paper: S. El-Hakim, J. Fryer, and M. Picard. Modeling and Visualization of Aboriginal Rock Art in the Baiame Cave. International Society for Photogrammetry and Remote Sensing (ISPRS) Congress in Istanbul, July 2004. Contributed to Modeling & Animation.
Animated Film: PORTALS
Synopsis: This movie takes the audience on a journey to a world where every object, artwork, and architecture is built from reality with 3-D Photography. Walk through monuments, manipulate objects and statues, and fly inside renaissance paintings. The monuments were reconstructed from digital images and image-based modeling based on Photogrammetry, bundle adjustment, and texture mapping using in-house software tools and a commercial package (ShapeCapture). The statues and small objects were digitized by a laser scanner with 10-microns resolution and modeled by PolyWorks software. The paintings were turned into 3D using our new single image 3D technique (SIGGRAPH'01 sketch).
Presented at SIGGRAPH Animation Theatres - Computer Animation Festival in San Antonio, Texas, July 2002. Contributed to 3D Digitizing & Modeling.
Thesis: Realism in 3D Virtual Spaces: Improving Texture Quality in Image-Based Modeling Systems through Application of High Dynamic Range Imagery
Abstract: This thesis presents a contribution to visual realism in virtual environments by investigating methods for improving texture quality in image-based modeling systems. The particular problem addressed is representing the high dynamic range (HDR) of real scenes, which may vary from deep shadow to brilliant highlights. The specific goals of this project were to identify and apply techniques to improve the visibility of texture in images of HDR scenes.
First, a procedure was developed to create accurate HDR images by assembling multiple exposures of a test scene in Debevec's HDR Shop. All stages of the procedure were optimized: selection of a suitable camera, acquisition of photographs, calibration of the camera response curve, and assembly of the HDR image from a low dynamic range image sequence. Compression of the HDR images was then investigated for both global mapping and spatially variant operators. Plug-ins for HDR Shop were written and successfully implemented for a log scale conversion and histogram adjustment. The resulting images displayed improved visibility across the luminance range, but with reduced local contrast. This report also presents a review of existing difficulties with acquiring realistic texture maps for image-based models.
BASc thesis project completed August, 2002. Co-supervised by Sabry El-Hakim, Visual Information Technology Group, National Research Council of Canada; and Demetri Terzopoulos, Computer Science Department, University of Toronto.
Term Paper: Feasibility Study: A Photogrammetric Approach to Architecture 3-D Modeling
Abstract: 3D computer modeling of architecture is an application seen in many industries. However, current modelling systems are limited to unnatural texture appearance, tedious methods, and restricted range in scale. This paper analyses the feasibility of an alternate approach to modeling and rendering architecture from a sparse set of photographs.
The modeling method is an interactive photogrammetric system that recovers geometry from sets of overlapping photographs. The method is efficient as it exploits the geometric structures and symmetries common in architecture. The technique also creates realistic texture maps by projecting original photographs onto the recovered geometry. Moreover, view-dependent texture mapping uses all available image information to produce the most photo-realistic renderings and simulate unmodeled geometry. To increase the range of modeling applications, the photogrammetry system integrates data from different sources. The system combines models from multiple images, single images, and laser sensors. Although additional advancements are necessary to incorporate lighting realism and automation, photogrammetry proves to be a feasible method for creating realistic models with efficiency and flexibility.
Technical Writing paper completed April, 2002. Course taught by Dr. Peter Weiss, University of Toronto.
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