Now showing items 1-20 of 35

    • 2-D Locally Regularized Tissue Strain Estimation From Radio-Frequency Ultrasound Images: Theoretical Developments and Results on Experimental Data 

      Author: Brusseau, Elisabeth; Kybic, Jan; Déprez, Jean-François; Basset, Olivier
      (IEEE, 2008-02)
      In this paper, a 2-D locally regularized strain estimation method for imaging deformation of soft biological tissues from radio-frequency (RF) ultrasound (US) data is introduced. Contrary to most 2-D techniques that model ...
    • 3D Ultrasound real-time monitoring of surgical tools 

      Author: Gaufillet, Fabian; Liebgott, Hervé; Uherčík, Marián; Cervenansky, Fréderic; Kybic, Jan; Cachard, Christian
      (IEEE, 2010-10)
      To assist surgeons during their surgical operations, which involve a tool insertion, a real-time application which is able to localise the surgical tool during its movement is proposed. The position of the needle is estimated ...
    • A common formalism for the integral formulations of the forward EEG problem 

      Author: Kybic, Jan; Clerc, Maureen; Abboud, Toufic; Faugeras, Olivier; Keriven, Renaud; Papadopoulo, Théo
      (IEEE, 2005-01)
      The forward electroencephalography (EEG) problem involves finding a potential V from the Poisson equation ∇·(σ∇V)=f, in which f represents electrical sources in the brain, and σ the conductivity of the head tissues. In the ...
    • Active Testing Search for Point Cloud Matching 

      Author: Amável Pinheiro, Miguel; Sznitman, Raphael; Serradell, Eduard; Kybic, Jan; Moreno-Noguer, Francesc; Fua, Pascal
      (Springer, 2013)
      We present a general approach for solving the point-cloud matching problem for the case of mildly nonlinear transformations. Our method quickly nds a coarse approximation of the solution by exploring a reduced set of ...
    • Bootstrap Optical Flow Confidence and Uncertainty Measure 

      Author: Kybic, Jan; Nieuwenhuis, Claudia
      (Elsevier, 2011)
      We address the problem of estimating the uncertainty of optical flow algorithm results. Our method estimates the error magnitude at all points in the image. It can be used as a confidence measure. It is based on bootstrap ...
    • Bootstrap Resampling for Image Registration Uncertainty Estimation Without Ground Truth 

      Author: Kybic, Jan
      (IEEE, 2010-01)
      We address the problem of estimating the uncertainty of pixel based image registration algorithms, given just the two images to be registered, for cases when no ground truth data is available. Our novel method uses bootstrap ...
    • Classification of microscopy images of Langerhans islets 

      Author: Švihlík, Jan; Kybic, Jan; Habart, David; Berková, Zuzana; Girman, Peter; Kříž, Jan; Zacharovová, Klára
      (SPIE, 2014)
      Evaluation of images of Langerhans islets is a crucial procedure for planning an islet transplantation, which is a promising diabetes treatment. This paper deals with segmentation of microscopy images of Langerhans islets ...
    • Comparison of Methods for Tool Localization in Biological Tissue from 3D Ultrasound Data 

      Author: Barva, Martin; Kybic, Jan; Hlaváč, Václav; Liebgott, Hervé; Cachard, Christian
      (IEEE, 2006-10)
      In medical applications, miniature surgical instruments such as needles, or electrodes are introduced into human body. The position of instrument in tissue can be estimated using 3D ultrasound. In previous publications, ...
    • Discrete curvature calculation for fast level set segmentation 

      Author: Kybic, Jan; Krátký, Jakub
      (IEEE, 2009-11)
      Fast level set methods replace continuous PDEs by a discrete formulation, improving the execution times. The regularization in fast level set methods was so far handled indirectly via level set function smoothing. We propose ...
    • Fast no ground truth image registration accuracy evaluation: Comparison of bootstrap and Hessian approaches 

      Author: Kybic, Jan
      (IEEE, 2008-05)
      Image registration algorithms provide a displacement field between two images. We consider the problem of estimating accuracy of the calculated displacement field from the input images only and without assuming any specific ...
    • Fast Parametric Elastic Image Registration 

      Author: Kybic, Jan; Unser, Michael
      (IEEE, 2003-11)
      We present an algorithm for fast elastic multidimensional intensity-based image registration with a parametric model of the deformation. It is fully automatic in its default mode of operation. In the case of hard real-world ...
    • Generalized Sampling: A Variational Approach. Part I: Theory 

      Author: Kybic, Jan; Blu, Thierry; Unser, Michael
      (IEEE, 2002-08)
      We consider the problem of reconstructing a multidimensional vector function fin: Rm→Rn from a finite set of linear measures. These can be irregularly sampled responses of several linear filters. Traditional approaches ...
    • Generalized Sampling: A Variational Approach. Part II: Applications 

      Author: Kybic, Jan; Blu, Thierry; Unser, Michael
      (IEEE, 2002-08)
      The variational reconstruction theory from a companion paper finds a solution consistent with some linear constraints and minimizing a quadratic plausibility criterion. It is suitable for treating vector and multidimensional ...
    • High-Dimensional Mutual Information Estimation For Image Registration 

      Author: Kybic, Jan
      (IEEE, 2004-10)
      We present a new algorithm for mutual information estimation for image registration based on the nearest neighbor entropy estimator of Kozachenko and Leonenko. We modify the algorithm to be numerically robust and computationally ...
    • jSLIC : superpixels in ImageJ 

      Author: Borovec, Jiří; Kybic, Jan
      (Czech Society for Cybernetics and Informatics, 2014)
      This paper presents the implementation and particular improvements on the superpixel clustering algorithm - SLIC (Simple Linear Iterative Clustering). The main contribution of the jSLIC is a significant speed-up of the ...
    • Line filtering for detection of microtools in 3D ultrasound data 

      Author: Uherčík, Marián; Kybic, Jan; Cachard, Christian; Liebgott, Hervé
      (IEEE, 2009-09)
      We propose a robust method for localization of elongated surgical tools in 3D ultrasound data based on shape analysis. The tubular structures in input data are enhanced by a line filter in the pre-processing phase. A new ...
    • Line Filtering for Surgical Tool Localization in 3D Ultrasound Images 

      Author: Uherčík, Marián; Kybic, Jan; Zhao, Yue; Cachard, Christian; Liebgott, Hervé
      (Elsevier, 2013)
      We present a method for automatic surgical tool localization in 3D ultrasound images based on line ltering, voxel classi cation and model tting. A possible application is to provide assistance for biopsy needle or ...
    • Model Fitting Using RANSAC for Surgical Tool Localization in 3-D Ultrasound Images 

      Author: Uherčík, Marián; Kybic, Jan; Liebgott, Hervé; Cachard, Christian
      (IEEE, 2010-08)
      Ultrasound guidance is used for many surgical interventions such as biopsy and electrode insertion. We present a method to localize a thin surgical tool such as a biopsy needle or a microelectrode in a 3-D ultrasound image. ...
    • A Multi-Frequency Approach to Increase the Native Resolution of Ultrasound Images 

      Author: Varray, François; Cachard, Christian; Kybic, Jan; Novell, Anthony; Bouakaz, Ayache; Basset, Olivier
      (IEEE, 2012)
      In ultrasound (US), a natural competition exists between the resolution of the image and the depth-of-field (DOF) into the medium, competition which is difficult to overcome with current US probe. Using large bandwidth ...
    • Multi-resolution parallel integral projection for fast localization of a straight electrode in 3D ultrasound images 

      Author: Uherčík, Marián; Kybic, Jan; Liebgott, Hervé; Cachard, Christian
      (IEEE, 2008-05)
      We address the problem of fast and accurate localization of miniature surgical instruments like needles or electrodes using 3D ultrasound (US). An algorithm based on maximizing a parallel integral transform (PIP) can ...