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In this paper, we present a review of existing techniques and systems for tracking multiple occluding objects using one or more cameras. Following a formulation of the occlusion problem, we divide these techniques into two groups: merge-split (MS) approaches and straight-through (ST) approaches. Then, we consider tracking in ball game applications, with(More)
This article presents a modular architecture for multi-camera tracking in the context of sports broadcasting. For each video stream, a geometrical module continuously performs the image-to-model homography estimation. A local-feature based tracking module tracks the players in each view. A supervisor module collects, associates and fuses the data provided(More)
We first generalize the concept of clutter power spectrum locus so that it can be applied to arbitrary antenna arrays. This locus is a curve in the 4D space of the Doppler frequency and the 3 spatial frequencies. This generalization is valid for both monostatic and bistatic radar configurations. We show that the customary clutter power spectrum locus(More)
Current neuronavigation systems cannot adapt to changing intraoperative conditions over time. To overcome this limitation, we present an experimental end-to-end system capable of updating 3D preoperative images in the presence of brain shift and successive resections. The heart of our system is a nonrigid registration technique using a biomechanical model,(More)
Edges are a fundamental clue for analyzing, interpreting, and understanding 3D scenes: they describe objects boundaries. Available edge detection methods are not suited for 3D cameras such as the Kinect or a time-of-flight camera: they are slow and do not take into consideration the characteristics of the cameras. In this paper, we present a fast jump edge(More)
This paper presents a novel approach to tracking ground targets in multiple cameras. A target is tracked not only in each camera but also in the ground plane by individual particle filters. These particle filters collaborate in two different ways. First, the particle filters in each camera pass messages to those in the ground plane where the multi-camera(More)
An original signal processing algorithm is presented to automatically extract, on a stride-by-stride basis, four consecutive fundamental events of walking, heel strike (HS), toe strike (TS), heel-off (HO), and toe-off (TO), from wireless accelerometers applied to the right and left foot. First, the signals recorded from heel and toe three-axis(More)
We introduce a new, efficient approach for modelling the deformation of organs following surgical cuts, retractions, and resections. It uses the extended finite element method (XFEM), recently developed in " fracture mechanics " for dealing with cracks in mechanical parts. XFEM eliminates the computationally-expensive remeshing that would be required if the(More)
This paper presents a new approach for tracking objects in complex situations such as people in a crowd or players on a soccer field. Each object in the image is represented by several interest points (IPs). These IPs are obtained using a color version of the Harris IP detector. Each IP is characterized by the local appearance (chromatic first-order local(More)
The application of adaptive (i.e., data-dependent) mathematical morphology techniques to range imagery, i.e., the use of structuring elements (SEs) that automatically adjust to the gray-scale values in a range image in order to deal with features of known physical sizes, is discussed. The technique is applicable to any type of image for which the distance(More)