Workshop on Motion and Video Computing, 2002. Proceedings.

9-9 Dec. 2002

Filter Results

Displaying Results 1 - 25 of 40
  • Proceedings Workshop on Motion and Video Computing (MOTION 2002)

    Publication Year: 2002
    Request permission for commercial reuse | PDF file iconPDF (260 KB)
    Freely Available from IEEE
  • Author index

    Publication Year: 2002, Page(s): 257
    Request permission for commercial reuse | PDF file iconPDF (160 KB)
    Freely Available from IEEE
  • Infinitesimal motion estimation from multiple central panoramic views

    Publication Year: 2002, Page(s):229 - 234
    Cited by:  Papers (5)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (295 KB) | HTML iconHTML

    We present an algorithm for infinitesimal motion estimation from multiple central panoramic views. We first derive the optical flow equations for central panoramic cameras as a function of both pixel coordinates and back-projection rays. We then derive a rank constraint on the optical flows across many frames, which must lie in a six dimensional subspace of a higher-dimensional space. We then prop... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A linear model for simultaneous estimation of 3D motion and depth

    Publication Year: 2002, Page(s):220 - 225
    Cited by:  Papers (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (435 KB) | HTML iconHTML

    A novel model for simultaneous estimation of full 3D motion and 3D position in world coordinates from multi camera sequences is presented. To this end scene flow (see Vedula, S. et al., ICCV 1999, p.722-9, 1999) and disparity are estimated in a single estimation step. The key idea is to interpret sequences of 2 or more cameras as one 4D data set. In this 4D space, a given motion model, a camera mo... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A three-mode expressive feature model of action effort

    Publication Year: 2002, Page(s):139 - 144
    Cited by:  Papers (4)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (291 KB) | HTML iconHTML

    We present an expressive feature model for recognizing the performance effort of human actions. A set of low and high effort examples for an action are initially factored into its three-mode principal components, followed by a learning phase to compute the expressive features required to bring the model estimation of effort into agreement with perceptual judgements. The approach is demonstrated us... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Object detection with multiple cameras

    Publication Year: 2002, Page(s):187 - 192
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (3854 KB) | HTML iconHTML

    The paper presents an algorithm for detecting objects from multiple cameras. The algorithm (1) minimizes the effect of shadows, (2) detects and solves occlusion and (3) fuses objects that are detected in more than one camera. The algorithm was developed as part of SORTTS (soccer real-time tracking system), a tracking system based on a set of video cameras that covers a large area. The paper also r... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A variational framework for active and adaptative segmentation of vector valued images

    Publication Year: 2002, Page(s):56 - 61
    Cited by:  Papers (84)  |  Patents (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (629 KB) | HTML iconHTML

    Much effort has been made in integrating different information in a variational framework to segment images. Recent works on curve propagation were able to incorporate stochastic information (see Paragios, N. and Deriche, R., J. Visual Commun. and Image Representation, 2002; Zhu, S. and Yuille, A., 1996) and prior knowledge on shapes (see Cremers, D. et al., 2002; Rousson M. and Paragios, N., 2002... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A hierarchical approach for obtaining structure from two-frame optical flow

    Publication Year: 2002, Page(s):214 - 219
    Cited by:  Papers (5)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (4332 KB) | HTML iconHTML

    A hierarchical iterative algorithm is proposed for extracting structure from two-frame optical flow. The algorithm exploits two facts: one is that in many applications, such as face and gesture recognition, the depth variation of the visible surface of an object in a scene is small compared to the distance between the optical center and the object; the other is that the time aliasing problem is al... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Real-time posture and activity recognition

    Publication Year: 2002, Page(s):133 - 138
    Cited by:  Papers (7)  |  Patents (4)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (497 KB) | HTML iconHTML

    We propose an algorithm for human posture and activity recognition for uncompressed and compressed (MPEG) video inputs. A real-time compression domain technique is developed to recognize different postures such as standing, pointing left/right, opening arms, etc. by using an eigenspace representation of human silhouettes obtained from AC-DCT coefficients. The system stores frames with specific pos... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Density estimation-based information fusion for multiple motion computation

    Publication Year: 2002, Page(s):241 - 246
    Cited by:  Papers (3)  |  Patents (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (1180 KB) | HTML iconHTML

    Vision tasks, such as motion analysis, object tracking, robot localization, and 3D modeling, often require the fusion of estimates coming from different sources. Most of the fusion algorithms, however, are not robust with respect to outliers and only consider one source models. Their performance deteriorates when initial assumptions are not valid (e.g., the presence of outliers in the data or data... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Video frame categorization using sort-merge feature selection

    Publication Year: 2002, Page(s):72 - 77
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (281 KB) | HTML iconHTML

    Feature selection for video categorization is impractical with existing techniques. We present a novel algorithm to select a very small subset of image features. We reduce the cardinality of the input data by sorting the individual features by their effectiveness in categorization, and then merging pairwise these features into feature sets of cardinality two. Repeating this sort-merge process seve... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Real-time tracking of quad-marked surfaces

    Publication Year: 2002, Page(s):253 - 256
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (861 KB) | HTML iconHTML

    We introduce a real-time tracking procedure for a collection of quads marked on a surface. A fast image alignment is used for tracking individual quads, and local mutual relations are enforced for the corresponding collection of quad homographies. The resulting procedure runs at the video frame rate for a variety of moving surfaces. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Segmentation and tracking of interacting human body parts under occlusion and shadowing

    Publication Year: 2002, Page(s):105 - 111
    Cited by:  Papers (29)  |  Patents (14)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (332 KB) | HTML iconHTML

    The paper presents a system to segment and track multiple body parts of interacting humans in the presence of mutual occlusion and shadow. The color image sequence is processed at three levels: pixel level, blob level, and object level. A Gaussian mixture model is used at the pixel level to train and classify individual pixel colors. A Markov random field (MRF) framework is used at the blob level ... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Continuous multi-views tracking using tensor voting

    Publication Year: 2002, Page(s):181 - 186
    Cited by:  Papers (8)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (1028 KB) | HTML iconHTML

    The paper presents a new approach for continuous tracking of moving objects observed by multiple fixed cameras. The continuous tracking of moving objects in each view is realized using a tensor voting based approach. We infer objects' trajectories by performing a perceptual grouping in 2D+t using tensor voting. Also, a multi-scale approach to bridge gaps in object trajectories is presented The tra... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Joint space-time motion-based segmentation of image sequences with level set PDEs

    Publication Year: 2002, Page(s):50 - 55
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (544 KB) | HTML iconHTML

    We present a novel approach to motion segmentation by formulating it as the computation of the volume spanned by moving regions in the 3-dimensional spatio-temporal domain, in contrast to standard approaches to motion segmentation which are based on 2-dimensional spatial segmentations. We propose a Bayesian formulation for motion-based segmentation of image sequences, and we solve this Bayesian es... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Interactive indoor scene reconstruction from image mosaics using cuboid structure

    Publication Year: 2002, Page(s):208 - 213
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (359 KB) | HTML iconHTML

    We describe a method for reconstructing indoor scenes from image mosaics using prior knowledge of the cuboid structure of the environment. The method is inspired by traditional approaches to the camera pose estimation problems known as the PnL (perspective n lines) and PnA (perspective n angles) problems. We show that a cuboid can be reconstructed from the images of three of its corners. The neces... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Tracking video objects using active contours

    Publication Year: 2002, Page(s):90 - 95
    Cited by:  Papers (4)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (438 KB) | HTML iconHTML

    We address the problem of tracking video objects through several frames. We present a new tracking algorithm using the active contour theory framework. Our first contribution is to define a new tracking criterion combining geometrical and region-based features. Our second contribution is to provide the differentiation of the criterion and to deduce the evolution equation of the active contour. Fin... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Comparative study of coarse head pose estimation

    Publication Year: 2002, Page(s):125 - 130
    Cited by:  Papers (30)  |  Patents (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (477 KB) | HTML iconHTML

    For many practical applications, it is sufficient to estimate a coarse head pose to infer gaze direction. Indeed, for any application in which the camera is situated unobtrusively in an overhead corner, the only possible inference is coarse pose because of the limitations of the quality and resolution of the incoming data. However, the vast majority of research in head pose estimation deals with t... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Multi view image surveillance and tracking

    Publication Year: 2002, Page(s):169 - 174
    Cited by:  Papers (66)  |  Patents (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (848 KB) | HTML iconHTML

    The paper presents a set of methods for multi view image tracking using a set of calibrated cameras. We demonstrate how effective the approach is for resolving occlusions and tracking objects between overlapping and non-overlapping camera views. Moving objects are initially detected using background subtraction. Temporal alignment is then performed between each video sequence in order to compensat... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A robust subspace approach to layer extraction

    Publication Year: 2002, Page(s):37 - 43
    Cited by:  Papers (8)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (482 KB) | HTML iconHTML

    Representing images with layers has many important applications, such as video compression, motion analysis, and 3D scene analysis. The paper presents a robust subspace approach to extracting layers from images reliably by taking advantage of the fact that homographies induced by planar patches in the scene form a low dimensional linear subspace. Such a subspace provides not only a feature space w... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Automatic detection of rigid point matches

    Publication Year: 2002, Page(s):235 - 240
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (324 KB) | HTML iconHTML

    The perspective projections of n physical points on two views (stereovision) are constrained as soon as n ≥ 8. However, to prove, in practice, the existence of a rigid motion between two images, more than 8 point matches are desirable in order to compensate for the limited accuracy of the matches. We propose a computational definition of rigidity and a probabilistic criterion to rate the meanin... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Bayesian-based performance prediction for gait recognition

    Publication Year: 2002, Page(s):145 - 150
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (4225 KB) | HTML iconHTML

    Existing gait recognition approaches do not give their theoretical or experiential performance predictions. Therefore, the discriminating power of gait as a feature for human recognition cannot be evaluated. We first propose a kinematic-based approach to recognize humans by gait. The proposed. approach estimates 3D human walking parameters by performing a least squares fit of the 3D kinematic mode... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Video synthesis made simple with the X-slits projection

    Publication Year: 2002, Page(s):195 - 200
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (612 KB) | HTML iconHTML

    We propose novel algorithms for image based rendering (IBR) by simulating a new family of scene-to-image projections, the crossed-slits (X-slits) projections. New X-slits images can be easily generated from a sequence of images captured by a translating pinhole camera, and those images look compelling and realistic. We show how this can be used for rendering movies of virtual walkthroughs by a ver... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Indexing key positions between multiple videos

    Publication Year: 2002, Page(s):65 - 71
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (518 KB) | HTML iconHTML

    Given two or more video sequences containing similar human activities (running, jumping, etc.), we want to devise a method which extracts spatio-temporal signatures associated with these activities, compares these signatures, and aligns key positions from different videos. We introduce a method which, in conjunction with a number of hypotheses, allows the analysis of the motion of specific body pa... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • How well can wavelet denoising improve the accuracy of computing fundamental matrices?

    Publication Year: 2002, Page(s):247 - 252
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (531 KB) | HTML iconHTML

    The existence of noise is a serious obstacle for solving many computer vision problems. Computing the fundamental matrix is a typical one. Motivated by the success of the wavelet denoising technique in image processing, we study the interesting topic of how well wavelet denoising can improve the accuracy of computing fundamental matrices. The answer depends on: 1) what wavelets should be applied; ... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.