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ABSTRACT: The recent availability of broadband Internet access and web-based visualization techniques is paving the way for a large scale use of 3D landscape and city models for a great variety of professional and mass market services. To make such services appealing to a large audience, these 3D models must reach a sufficient level of realism and accuracy. Many solutions are now available to automatically generate 3D models of huge urban environments. Geographic Information System (GIS) databases (i.e. terrain elevation grids, ortho photographs, buildings footprint and height) provide a good basis for generating such models at affordable cost with minimum human intervention. However, the growing size of the transmitted data will favour streaming over download-and- play. Moreover, the new market for virtual worlds is likely to be soon demanding in interoperability. The goal of this paper is to show how solutions based on hierarchical LOD models and view-dependent progressive streaming can efficiently be implemented using the MPEG-4 AFX standard in peer-to-peer networks architectures, solving both streaming and interoperability issues.
3DTV Conference: The True Vision - Capture, Transmission and Display of 3D Video, 2008; 06/2008
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ABSTRACT: To improve the visualization of large 3D landscapes and city models in a network environment, the authors use two different types of hierarchical level-of-detail models for terrain and groups of buildings. They also leverage the models to implement progressive streaming in both client-server and peer-to-peer network architectures. Visualizing large photorealistic 3D landscapes and city models has received significant attention over the last 10 years in the computer graphics community. More recently, the availability of broadband Internet access and Web-based visualization techniques is paving the way for large-scale 3D landscapes and city models for a variety of professional and mass-market services. To make such services appealing to a large audience, these 3D models must reach a sufficient level of realism and accuracy. Many solutions are now available to automatically generate 3D models of huge urban environments. Geographic information system (GIS) databases (such as terrain elevation grids, orthophotographs, and a building's footprint and height) provide a good basis for generating such models at affordable cost with minimum human intervention. In the future, the accuracy and realism of 3D city models will be improved thanks to recent progress in data capturing techniques.
IEEE Computer Graphics and Applications 12/2007; 27(6):70-79. · 1.41 Impact Factor
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Workshop on Immersive Communication and Broadcast Systems (ICOB 2005), Berlin; 11/2005
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ABSTRACT: Wavelet methods for geometry encoding is a recently emerged superset of multiresolution analysis which has proven to be very efficient in terms of compression and adaptive transmission of three-dimensional (3-D) content. The decorrelating power and space/scale localization of wavelets enable efficient compression of arbitrary meshes as well as progressive and local reconstruction. Recent techniques based on zerotree compression have shown to be among the best lossy mesh compression methods, while remaining compatible with selective transmission of geometric data at various levels of detail. While some progressive reconstruction schemes have been proposed in the past, we show in this paper that this representation, recently proposed in the MPEG4 standard, can be efficiently used to perform real-time, view-dependent reconstruction of large meshes. The proposed system combines algorithms for local updates, cache management, and server/client dialog. The local details management is an improvement of progressive reconstructions built on top of hierarchical structures. It enables fast, homogeneous accommodation and suppression of wavelet coefficients at any level of subdivision, with time complexity independent of the size of the reconstructed mesh. The cache structure wisely exploits the hierarchical character of the received data, in order to avoid redundant information transmission. The whole system enables the client to have total control on the quality of navigation according to its storage and processing capabilities, whatever the size of the mesh.
IEEE Transactions on Circuits and Systems for Video Technology 08/2004; · 1.65 Impact Factor
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SIGGRAPH, Los Angeles; 08/2004
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ABSTRACT: The goal of the MOVIE very large-scale integration chip is to
facilitate the development of software-only solutions for real-time
video processing applications. This chip can be seen as a building block
for single-instruction, multiple-data processing, and its architecture
has been designed so as to facilitate high-level language programming.
The basic architecture building block associates a subarray of
computation processors with an I/O processor. A module can be seen as a
small linear, systolic-like array of processing elements, connected at
each end to the I/O processor. The module can communicate with its two
nearest neighbors via two communication ports. The chip architecture
also includes three 16-bit video ports. One important aspect in the
programming environment is the C-stolic programming language. C stolic
is a C-like language augmented with parallel constructs, which allow the
differentiation between the array controller variables (scalar
variables) and the local variables in the array structure (systolic
variables). A statement operating on systolic variables implies a
simultaneous execution on all the cells of the structure. Implementation
examples of MOVIE-based architectures dealing with video compression
algorithms are given
IEEE Transactions on Circuits and Systems for Video Technology 10/1999; · 1.65 Impact Factor
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ABSTRACT: This paper shows how a real-time simulator of moving pictures compression algorithms can be rapidly assembled using a basic building block, here called MOVIE (MOdule for Video Experimentation). The internal architecture of the MOVIE VLSI chip can be compared to a small systolic machine made of a 32-bit I/O processor, a reduced linear array of 16-bit computation processors and data video input/output mechanisms. Externally, the chip is provided with four 16-bit bidirectional data ports and three 16-bit bidirectional data video port. Several MOVIE chips can be easily clustered to allow the size of the linear array of computation processors to be increased. The MOVIE chip is fully programmable in a high level language in order to make program developments easier
Application Specific Array Processors, 1995. Proceedings., International Conference on; 08/1995
