3d imaging is a popular method for acquiring accurate models for a variety of applications. However, the size of the geometric features that can be modeled in this manner is dependant on the scanning system's reso...
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ISBN:
(纸本)9780769528250
3d imaging is a popular method for acquiring accurate models for a variety of applications. However, the size of the geometric features that can be modeled in this manner is dependant on the scanning system's resolution. This paper presents a method that attempts to accurately reconstruct regions whose features are at or below the system's scanning resolution, combining automatic region selection with a form of kriging. A curvature-based segmentation is followed by an automated geometry refinement procedure in which the model of spatial correlation between the irregularly sampled3ddata is automatically determined. Geometry refinement is done by a regularized kriging approach that is designed to preserve the sharp features typical to many 3d laser range applications. This method is validated on synthetic data, showing that the accuracy of our method is higher than that of its standard competitors. Then, the performance on real data is demonstrated through several examples.
Philips is realizing an end-to-end3ddisplay solution from 3d content creation to visualization. This development fits in our long-standing tradition of combining expertise in video processing with our strength in di...
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ISBN:
(纸本)9780769528250
Philips is realizing an end-to-end3ddisplay solution from 3d content creation to visualization. This development fits in our long-standing tradition of combining expertise in video processing with our strength in display development to create the most exciting and best viewing experience. Philips developed several high-quality 3ddisplays, ranging in resolution, viewing angle, depth experience, and sizes from 4 '' to 40 '' and up. Backwards compatibility with 2d content is enabled via signal-processing or opto-electronic 3d & 2ddual mode displays. Content creation and conversion methods are provided, which are a key factor for the success of 3ddisplays. Fully automatic conversion from monoscopic 2d content into 3d enables the re-use of all existing 2d video material. Further methods enable 3d animation/design, 2d to 3d conversion in post-production and live capture of new 3d content. Our,efforts in MPEG standardization towards the "2d-plus-depth" format for 3d video enables a flexible interface between the variety in 3d content creation methods and the range in 3ddisplays. Furthermore, the 3d format is compatible with existing 2d content, standards and infrastructure. Currently, Philips offers several commercial 3d products for professional use such as digital signage, and progress is being made towards consumer products such as 3dTV.
Interactive network-based navigation over large urban environments raises difficult problems due to the size and complexity of these scenes. In this paper, we present a client-server system allowing navigation over 3d...
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ISBN:
(纸本)9780769528250
Interactive network-based navigation over large urban environments raises difficult problems due to the size and complexity of these scenes. In this paper, we present a client-server system allowing navigation over 3d cities in real time. due to a novel progressive and hierarchical representation of 3d models of densely built urban areas, only perceptible details for all the regions visible from a given viewpoint are progressively streamed to visualisation clients. Furthermore, efficient coding methods are used to compress the representation data allowing quick start-up of the interactive visualisation with a highly-detailed model. This is achieved through a set of dedicated algorithms allowing a very large city model to be structured into a multi-resolution representation. The method efficiently exploits the fact that most automated modelling techniques of urban scenes provides 2d1/2 models (building footprint, height, altitude, So as to efficiently and faithfully model complex buildings, a procedural representation for roofs and facades is proposed. Finally, we present an MPEG4 compatible implementation based on the introduction of new node types with the associated bitstream.
Thanks to their high performance and programmability, the latest graphics cards can now be used for scientific purpose. They are indeed very efficient parallel Single Instruction Multiple data (SIMd) machines. This ne...
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ISBN:
(纸本)9780769528250
Thanks to their high performance and programmability, the latest graphics cards can now be used for scientific purpose. They are indeed very efficient parallel Single Instruction Multiple data (SIMd) machines. This new trend is called General Purpose computation on Graphics processing Unit (GPGPU [4]). Regarding the stereo problem, variational methods based on deformable models provide dense, smooth and accurate results. Nevertheless, they prove to be slower than usual disparity-based approaches. In this paper we present a dense stereo algorithm, handling occlusions, using three cameras as inputs and entirely implemented on a Graphics processing Unit (GPU). Experimental speedups prove that our approach is efficient and perfectly adapted to the GPU, leading to nearly video frame rate reconstruction.
3dtransmission over unreliable networks needs to take into account the possibility of packet loss. In this work we describe a perceptually motivated strategy for joint transmission of texture and mesh over unreliable...
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ISBN:
(纸本)9780769528250
3dtransmission over unreliable networks needs to take into account the possibility of packet loss. In this work we describe a perceptually motivated strategy for joint transmission of texture and mesh over unreliable networks. The approach is described initially considering regular mesh structure, to show the utility of optimizing the texture-mesh tradeoff. In order to generalize our approach to arbitrary meshes we consider stripification of the mesh, combined with a strategy that does not need texture or vertex packets to be re-transmitted. Only the valence (connectivity) packets need to be re-transimitted;however, storage of valence information requires only 10% space compared to vertices and even less compared to photo-realistic texture. Thus, only less than 5% of the packets may need to be re-transmitted in the worst case to allow our algorithm to successfully reconstruct an acceptable object under severe packet loss. Results showing the implementation of the proposed approach are described.
detection of articulated objects such as humans is an important task in computer vision. We present a system that incorporates a variety of constraints in a unified multiview framework to automatically detect humans i...
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ISBN:
(纸本)9780769528250
detection of articulated objects such as humans is an important task in computer vision. We present a system that incorporates a variety of constraints in a unified multiview framework to automatically detect humans in possibly crowded scenes. These constraints include the kinematic constraints, the occlusion of one part by another and the high correlation between the appearance of parts such as the two arms. The graphical structure (non-tree) obtained is optimized in a nonparametric belief propagation framework using prior based search.
For AR applications the 3d position anddirection of the users view have to be determined in real time. At the same time, the augmentation, one or more 3d objects, have to be rendered. This article describes a distrib...
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ISBN:
(纸本)9780769528250
For AR applications the 3d position anddirection of the users view have to be determined in real time. At the same time, the augmentation, one or more 3d objects, have to be rendered. This article describes a distributed mobile AR-System designed for industrial service applications. By distributing the different tasks involved in AR, the computational load of the portable system can be minimized such that a small and lightweight computer can be used. The portable computer is connected to a backend server via WLAN. Minimisation of the bandwidth usage of the system ensures that 20 or more systems can operate on one standard WLAN access point. The main focus of this article is to minimise the computational load of the mobile system and the network load simultaneously.
Medial surfaces are popular representations of 3d objects in vision, graphics and geometric modeling. They capture relevant symmetries and part hierarchies and also allow for detaileddifferential geometric informatio...
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ISBN:
(纸本)9780769528250
Medial surfaces are popular representations of 3d objects in vision, graphics and geometric modeling. They capture relevant symmetries and part hierarchies and also allow for detaileddifferential geometric information to be recovered. However, exact algorithms for their computation from meshes must solve high-order polynomial equations, while approximation algorithms rarely guarantee soundness and completeness. In this article we develop a technique for computing the medial surface of an object with a polyhedral boundary, which is based on an analysis of the average outward flux of the gradient of its Euclidean distance function. This analysis leads to a coarse-to-fine algorithm implemented on a cubic lattice that reveals at each iteration the salient manifolds of the medial surface. We provide comparative results against a state-of-the-art method in the literature.
This paper proposes a new technique for modeling and matching three-dimensional rigid objects by encoding the fluctuation of the surface and the variation of its normal around an oriented point on the surface as the s...
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ISBN:
(纸本)9780769528250
This paper proposes a new technique for modeling and matching three-dimensional rigid objects by encoding the fluctuation of the surface and the variation of its normal around an oriented point on the surface as the surface expands. The surface of the object is encoded into two two-dimensional curves as the surface signature on each point, and then the collection of the signatures are used to model and match the object. The signatures implicitly encode the curvature and symmetry of the surface around an oriented point. This modeling technique is robust to scale, orientation, noise, patch resolution, occlusion, and cluttering.
We present a 3d outdoor scene scanner for the acquisition of kilometers-deep scenes in night conditions. Its imaging system is based on a compact and low-cost pulsed laser illuminator and a light-intensifier equipped ...
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ISBN:
(纸本)9780769528250
We present a 3d outdoor scene scanner for the acquisition of kilometers-deep scenes in night conditions. Its imaging system is based on a compact and low-cost pulsed laser illuminator and a light-intensifier equipped CCd camera. By precisely synchronizing both the illuminator and the camera shutter it is possible to acquire "slices" of the scene at specific known distances. We show that even with large laser pulses and without megahertz-capable electronics, the thirddimension can be recovered for the whole range of the scene by processing only two images acquired in specific conditions. As the pixel intensities of the images produced by active imaging systems vary with the square of the range, anddue to the limiteddynamics of image sensors, scanning long-range scenes with shorter "slices" allows the camera gain to be adjusted with respect to the range and the accuracy to be enhanced. The imaging system as well as the different image processing steps are detailed in this paper and an example of typical results is given.
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