Library

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Journal of mathematical imaging and vision 9 (1998), S. 49-67 
    ISSN: 1573-7683
    Keywords: geometric features ; transformation groups ; uniform distribution ; invariant measure ; invariant distance ; expected features ; mean features
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics
    Notes: Abstract Complex geometric features such as oriented points, lines or 3D frames are increasingly used in image processing and computer vision. However, processing these geometric features is far more difficult than processing points, and a number of paradoxes can arise. We establish in this article the basic mathematical framework required to avoid them and analyze more specifically three basic problems: (1) what is a random distribution of features, (2) how to define a distance between features, (3) and what is the “mean feature” of a number of feature measurements? We insist on the importance of an invariance hypothesis for these definitions relative to a group of transformations that models the different possible data acquisitions. We develop general methods to solve these three problems and illustrate them with 3D frame features under rigid transformations. The first problem has a direct application in the computation of the prior probability of a false match in classical model-based object recognition algorithms. We also present experimental results of the two other problems for the statistical analysis of anatomical features automatically extracted from 24 three-dimensional images of a single patient's head. These experiments successfully confirm the importance of the rigorous requirements presented in this article.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    ISSN: 1432-2315
    Keywords: Key words: Surgery simulation – Finite elements – Linear elasticity – Spring-mass models – Soft tissue modeling
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    Springer
    International journal of computer vision 1 (1987), S. 107-131 
    ISSN: 1573-1405
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Notes: Abstract We present a new approach to the stereo-matching problem. Images are individually described by aneighborhood graph of line segments coming from a polygonal approximation of the contours. The matching process is defined as the exploration of the largest components of adisparity graph built from the descriptions of the two images, and is performed by an efficient prediction and propagation technique. This approach was tested on a variety of man-made environments, and it appears to be fast and robust enough for mobile robot navigation and three-dimensional part-positioning applications.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    Springer
    International journal of computer vision 10 (1993), S. 183-197 
    ISSN: 1573-1405
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Notes: Abstract This article proposes a new approach to segment a discrete 3-D object into a structure of characteristic topological primitives with attached qualitative features. This structure can be seen itself as a qualitative description of the object, because —it is intrinsic to the 3-D object, which means it is stable to rigid transformations (rotations and translations); —it is locally defined, and therefore stable to partial occlusions and local modifications of the object structure; —it is robust to noise and small deformations, as confirmed by our experimental results. Our approach concentrates on topological properties of discrete surfaces. These surfaces may correspond to theexternal surface of the objects extracted by a 3-D edge detector, or to theskeleton surface obtained by a new thinning algorithm. Our labeling algorithm is based on very local computations, allowing massively parallel computations and real-time computations. An indirect result of these topological properties is a new characterization of simple points. We present a realistic experiment to characterize and locate spatially a complex 3-D medical object using the proposed segmentation of its skeleton.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    Springer
    International journal of computer vision 12 (1994), S. 79-104 
    ISSN: 1573-1405
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Notes: Abstract We present a new approach to the problem of matching 3-D curves. The approach has a low algorithmic complexity in the number of models, and can operate in the presence of noise and partial occlusions. Our method builds upon the seminal work of Kishon et al. (1990), where curves are first smoothed using B-splines, with matching based on hashing using curvature and torsion measures. However, we introduce two enhancements: - We make use of nonuniform B-spline approximations, which permits us to better retain information at high-curvature locations. The spline approximations are controlled (i.e., regularized) by making use of normal vectors to the surface in 3-D on which the curves lie, and by an explicit minimization of a bending energy. These measures allow a more accurate estimation of position, curvature, torsion, and Frénet frames along the curve. - The computational complexity of the recognition process is relatively independent of the number of models and is considerably decreased with explicit use of the Frénet frame for hypotheses generation. As opposed to previous approaches, the method better copes with partial occlusion. Moreover, following a statistical study of the curvature and torsion covariances, we optimize the hash table discretization and discover improved invariants for recognition, different than the torsion measure. Finally, knowledge of invariant uncertainties is used to compute an optimal global transformation using an extended Kalman filter. We present experimental results using synthetic data and also using characteristic curves extracted from 3-D medical images. An earlier version of this article was presented at the 2nd European Conference on Computer Vision in Italy.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    Springer
    International journal of computer vision 18 (1996), S. 99-119 
    ISSN: 1573-1405
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Notes: Abstract In this paper, we propose a new framework to perform nonrigid surface registration. It is based on various extensions of an iterative algorithm recently presented by several researchers (Besl and McKay, 1992; Champleboux et al., 1992; Chen and Medioni, 1992; Menq and Lai, 1992; Zhang, 1994) to rigidly register surfaces represented by a set of 3D points, when a prior estimate of the displacement is available. Our framework consists of three stages: •First, we search for the best rigid displacement to superpose the two surfaces. We show how to efficiently use curvatures to superpose principal frames at possible corresponding points in order to find a prior rough estimate of the displacement and initialize the iterative algorithm. •Second, we search for the best affine transformation. We introduce differential information in points coordinates: this allows us to match locally similar points. Then, we show how principal frames and curvatures are transformed by an affine transformation. Finally, we introduce this differential information in a global criterion minimized by extended Kalman filtering in order to ensure the convergence of the algorithm. •Third, we locally deform the surface. Instead of computing a global affine transformation, we attach to each point a local affine transformation varying smoothly along the surface. We call this deformation a locally affine deformation. All these stages are illustrated with experiments on various real biomedical surfaces (teeth, faces, skulls, brains and hearts), which demonstrate the validity of the approach.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 7
    Electronic Resource
    Electronic Resource
    Springer
    International journal of computer vision 26 (1998), S. 25-40 
    ISSN: 1573-1405
    Keywords: medical imaging ; adaptive meshes ; non-rigid motion ; differential geometry ; finite element method
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Notes: Abstract We describe a new method for computing the displacement vector field in time sequences of 2D or 3D images (4D data). The method is energy-minimizing on the space of correspondence functions; the energy is split into two terms, with one term matching differential singularities in the images, and the other constraining the regularity of the field. In order to reduce the computational time of the motion estimation, we use an adaptive image mesh, the resolution of which depends on the value of the gradient intensity. We solve numerically the minimization problem with the finite element method which gives a continuous approximation of the solution. We present experimental results on synthetic data and on medical images and we show how to use these results for analyzing cardiac deformations.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 8
    Title: Computer vision, virtual reality and robotics in medicine. 1st international conference CVRMed 95, Nice, France, April 3-6, 1995. Proceedings; 905
    Contributer: Ayache, Nicholas
    Publisher: Berlin u.a. :Springer,
    Year of publication: 1995
    Pages: 567 S.
    Series Statement: Lecture notes in computer science 905
    Type of Medium: Book
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 9
    Title: Surgery simulation and soft tissue modeling : International Symposium, IS4TM 2003, Juan-Les-Pins, France, June 12-13, 2003, proceedings; 2673
    Author: Ayache, Nicholas
    Publisher: Berlin [u.a.] :Springer,
    Year of publication: 2003
    Pages: XII, 386 S.
    Series Statement: Lecture notes in computer science 2673
    ISBN: 3-540-40439-2
    Type of Medium: Book
    Language: English
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 10
    Book
    Book
    Berlin :Springer Berlin,
    Title: Functional Imaging and Modeling of the Heart /; 5528
    Contributer: Ayache, Nicholas
    Edition: 1. Aufl.
    Publisher: Berlin :Springer Berlin,
    Year of publication: 2009
    Pages: XVII, 537 S. ; , 235 mm x 155 mm
    Series Statement: Lecture notes in computer science 5528
    ISBN: 978-3-642-01931-9
    Type of Medium: Book
    Language: English
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...