• Characterization of Complex Fractionated Atrial Electrograms by Sample Entropy: An International Multi-Center Study 

      Autor: Novák, Daniel
      (2015)
      Atrial fibrillation (AF) is the most commonly clinically-encountered arrhythmia. Catheter ablation of AF is mainly based on trigger elimination and modification of the AF substrate. Substrate mapping ablation of complex ...
    • Classification of microscopy images of Langerhans islets 

      Autor: 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 ...
    • Colour-Based Object Recognition for Video Annotation 

      Autor: Koubaroulis, Dirnitrios; Matas, Jiří; Kittler, Josef
      (IEEE, 2002)
      We propose a colour-based object recognition method for video annotation. The semantic gap between image measurements and symbolic labelling is bridged by assuming the existence of objects whose appearance can be associated ...
    • Comparison of face verification results on the XM2VTS database 

      Autor: Matas, J.; Hamouz, M.; Jonsson, K.; Kittler, J.; Li, Y.; Kotropoulos, C.; Tefas, A.; Pitas, I.; Teewoon Tan; Hong Yan; Smeraldi, F.; Bigun, J.; Capdevielle, N.; Gerstner, W.; Ben-Yacoub, S.; Abdeljaoued, Y.; Mayoraz, E.
      (IEEE, 2000)
      The pater presents results of the face verification contest that was organized in conjunction with International Conference on Pattern Recognition 2000. Participants had to use identical data sets from a large, publicly ...
    • Comparison of Methods for Tool Localization in Biological Tissue from 3D Ultrasound Data 

      Autor: 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, ...
    • Construction of Precise Local Affine Frames 

      Autor: Mikulik, Andrej; Matas, Jiří; Perd’och, Michal; Chum, Ondřej
      (IEEE, 2010-08)
      We propose a novel method for the refinement of Maximally Stable Extremal Region (MSER) boundaries to sub-pixel precision by taking into account the intensity function in the 2 × 2 neighborhood of the contour points. The ...
    • Dense Linear-Time Correspondences for Tracking 

      Autor: Obdržálek, Štěpán; Perd’och, Michal; Matas, Jiří
      (IEEE, 2008-06)
      A novel method is proposed for the problem of frame-to-frame correspondence search in video sequences. The method, based on hashing of low-dimensional image descriptors, establishes dense correspondences and allows large ...
    • Dimension Selection in Axis-Parallel Brent-STEP Method for Black-Box Optimization of Separable Continuous Functions 

      Autor: Pošík, Petr; Baudiš, Petr
      (ACM, 2015)
      The recently proposed Brent-STEP algorithm was gener alized for separable functions by performing axis-parallel searches, interleaving the steps in individual dimensions in a round-robin fashion. This article explores ...
    • Discrete curvature calculation for fast level set segmentation 

      Autor: 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 ...
    • Dynamic Approximate Entropy Electroanatomic Maps Detect Rotors in a Simulated Atrial Fibrillation Model 

      Autor: Novák, Daniel
      (2014)
      There is evidence that rotors could be drivers that maintain atrial fibrillation. Complex fractionated atrial electrograms have been located in rotor tip areas. However, the concept of electrogram fractionation, defined ...
    • Efficient Representation of Local Geometry for Large Scale Object Retrieval 

      Autor: Perd’och, Michal; Chum, Ondřej; Matas, Jiří
      (IEEE, 2009-06)
      State of the art methods for image and object retrieval exploit both appearance (via visual words) and local geometry (spatial extent, relative pose). In large scale problems, memory becomes a limiting factor - local ...
    • Efficient Sequential Correspondence Selection by Cosegmentation 

      Autor: Čech, Jan; Matas, Jiří; Perd’och, Michal
      (IEEE, 2008-06)
      In many retrieval, object recognition and wide baseline stereo methods, correspondences of interest points are established possibly sublinearly by matching a compact descriptor such as SIFT. We show that a subsequent ...
    • Efficient Sequential Correspondence Selection by Cosegmentation 

      Autor: Čech, Jan; Matas, Jiří; Perd’och, Michal
      (IEEE, 2010-09)
      In many retrieval, object recognition, and wide-baseline stereo methods, correspondences of interest points (distinguished regions) are commonly established by matching compact descriptors such as SIFTs. We show that a ...
    • Epipolar Geometry Estimation via RANSAC Benefits from the Oriented Epipolar Constraint 

      Autor: Chum, Ondřej; Werner, Tomáš; Matas, Jiří
      (IEEE, 2004-08)
      The efficiency of epipolar geometry estimation by RANSAC is improved by exploiting the oriented epipolar constraint. Performance evaluation shows that the enhancement brings up to a two-fold speed-up. The orientation test ...
    • Epipolar Geometry from Two Correspondences 

      Autor: Perd’och, Michal; Matas, Jiří; Chum, Ondřej
      (IEEE, 2006)
      A novel algorithm for robust RANSAC-like estimation of epipolar geometry (of uncalibrated camera pair) from two correspondences of local affine frames (LAFs) is presented. Each LAF is constructed from three points independently ...
    • Face Verification Using Error Correcting Output Codes 

      Autor: Kittler, J.; Ghaderi, R.; Windeatt, T.; Matas, J.
      (IEEE, 2001)
      The error correcting output coding (ECOC) approach to classifier design decomposes a multi-class problem into a set of complementary two-class problems. We show how to apply the ECOC concept to automatic face verification, ...
    • Face-TLD: Tracking-Learning-Detection applied to faces 

      Autor: Kalal, Zdenek; Mikolajczyk, Krystian; Matas, Jiří
      (IEEE, 2010-09)
      A novel system for long-term tracking of a human face in unconstrained videos is built on Tracking-Learning-Detection (TLD) approach. The system extends TLD with the concept of a generic detector and a validator which is ...
    • Fast Detection of Multiple Textureless 3-D Objects 

      Autor: Cai, Hongping; Werner, Tomáš; Matas, Jiří
      (Springer, 2013)
      We propose a fast edge-based approach for detection and approximate pose estimation of multiple textureless objects in a single image. The objects are trained from a set of edge maps, each showing one object in one pose. ...
    • Fast no ground truth image registration accuracy evaluation: Comparison of bootstrap and Hessian approaches 

      Autor: 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 

      Autor: 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 ...