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This paper introduces a new approach for non-rigid registration which is able to align two surfaces under large deformation. At the first stage, the two surfaces are remeshed to create two sub-meshes. Then, correspondences between the two sub-meshes are obtained by employing a robust probabilistic method. Reliable correspondences are used to find a global rigid transformation to bring the two surfaces closer. Using these correspondences and taking one sub-mesh as a deformation graph, the second stage applies a deformation model to align the two surfaces together. This stage solves for more correct correspondences as well as for a local transformation at each node simultaneously. With these two stages, the method deals robustly with large motion and preserves small details during the alignment process of the two surfaces. The efficiency of the method is demonstrated by comparing the alignment results it achieves with the results obtained by state-of-the-art methods. [ABSTRACT FROM AUTHOR]

Camera calibration is a critical step in many vision applications. It is a delicate and complex process that is highly sensitive to environmental conditions. This paper presents a novel virtual calibration technique that can be used to study the impact of various factors on the calibration parameters. To highlight the possibilities of the method, the calibration parameters’ behavior has been studied regarding the effects of tolerancing and temperature for a specific lens. This technique could also be used in many other promising areas to make calibration in the laboratory or in the field easier.

It has been proven experimentally that visual interactive simulation (VIS) is useful in specific contexts. Interaction with the simulated system remains one of the key issues that need to be addressed for VIS to be applied on a large-scale. Little work has been reported recently on using modern computers that offer new types of user interfaces for solving the problem of interactivity with simulations. This paper introduces the multichronic tree user interface concept that provides users with tools for interacting with and visualising multiple simultaneously running simulations. This new VIS concept builds on previous systems, formalises operations and adds several interactive features that can be supported by state-of-the-art computer architectures and display environments. A prototype of the multichronic tree concept is presented along with a discussion on how it could be integrated with other tools in a more general framework for helping users in their simulation exploration process.

Camera motion estimation plays an important role in digital video analysis algorithms such as video indexing and retrieval or automatic movie analysis. Several algorithms have been proposed to solve this problem in MPEG videos. This paper presents an optical flow-based approach for the camera motion estimation in all kinds of digital video formats, especially in movies. It compares the motion vector fields (MVFs) with six predefined templates to determine the type of motion. The MVFs are generated by using high-accuracy optical flow computation. The advantage of the method lies in its robustness to noisy environments such as false motion vectors and object motions. Comprehensive experiments with video clips extracted from well-known feature movies demonstrate the performance of the proposed approach.

In this text, we summarize recent works done in the use of visible and infrared imagery for surveillance applications. Moreover, we also present latest developments that have occurred in three partner institutions of the Québec, Canada area in this field. Our focus is on both hardware and software. Hardware here concerns channel registration and innovative optical systems while software is related to high level information extraction. Extensive literature review is provided

This paper presents a dynamic integration algorithm to triangulate a surface from multiple range views. This integration technique is based on the reparameterization of the canonic subsets of the Venn diagram of the set of range views. We compute a model based onN views from a model based onN-1 views by processing only the surface segments visible in theNth view. An experimental result shows that the proposed integration algorithm can process complex multipart objects containing holes.

This paper describes a sequential multiresolution surface modeling technique. The initial model consists in a surface triangulation resulting from the integration of a set of range views. Thereafter, a hierarchical triangulation algorithm iteratively removes vertices of the triangulation, always minimizing the retriangulation error. The equiangularity of the surface triangulation is optimized in 3-D space throughout the optimization process. Besides compressing surface information, the proposed technique preserves the topology of the triangulation and surface orientation discontinuities. Experimental models built from complex multipart objects with holes are presented.