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Author Josep Llados; Enric Marti; Jaime Lopez-Krahe
Title A Hough-based method for hatched pattern detection in maps and diagrams Type Conference Article
Year 1999 Publication Proceeding of the Fifth Int. Conf. Document Analysis and Recognition ICDAR ’99 Abbreviated Journal
Volume Issue Pages 479-482
Keywords
Abstract A hatched area is characterized by a set of parallel straight lines placed at regular intervals. In this paper, a Hough-based schema is introduced to recognize hatched areas in technical documents from attributed graph structures representing the document once it has been vectorized. Defining a Hough-based transform from a graph instead of the raster image allows to drastically reduce the processing time and, second, to obtain more reliable results because straight lines have already been detected in the vectorization step. A second advantage of the proposed method is that no assumptions must be made a priori about the slope and frequency of hatching patterns, but they are computed in run time for each hatched area.
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Notes DAG;IAM; Approved no
Call Number (down) IAM @ iam @ LIM1999b Serial 1580
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Author Josep Llados; Enric Marti
Title A graph-edit algorithm for hand-drawn graphical document recognition and their automatic introduction into CAD systems Type Journal Article
Year 1999 Publication Machine Graphics & Vision Abbreviated Journal
Volume 8 Issue Pages 195-211
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Abstract
Address
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Publisher Place of Publication Editor
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Notes DAG;IAM; Approved no
Call Number (down) IAM @ iam @ LIM1999 Serial 1568
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Author Josep Llados; Horst Bunke; Enric Marti
Title Structural Recognition of hand drawn floor plans Type Conference Article
Year 1996 Publication VI National Symposium on Pattern Recognition and Image Analysis Abbreviated Journal
Volume Issue Pages
Keywords Rotational Symmetry; Reflectional Symmetry; String Matching.
Abstract A system to recognize hand drawn architectural drawings in a CAD environment has been deve- loped. In this paper we focus on its high level interpretation module. To interpret a floor plan, the system must identify several building elements, whose description is stored in a library of pat- terns, as well as their spatial relationships. We propose a structural approach based on subgraph isomorphism techniques to obtain a high-level interpretation of the document. The vectorized input document and the patterns to be recognized are represented by attributed graphs. Discrete relaxation techniques (AC4 algorithm) have been applied to develop the matching algorithm. The process has been divided in three steps: node labeling, local consistency and global consistency verification. The hand drawn creation causes disturbed line drawings with several accuracy errors, which must be taken into account. Here we have identified them and the AC4 algorithm has been adapted to manage them.
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Corporate Author Thesis
Publisher Place of Publication Cordoba Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
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ISSN ISBN Medium
Area Expedition Conference
Notes DAG;IAM; Approved no
Call Number (down) IAM @ iam @ LIM1995 Serial 1565
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Author Josep Llados;Horst Bunke; Enric Marti
Title Using Cyclic String Matching to Find Rotational and Reflectional Symmetries in Shapes Type Conference Article
Year 1997 Publication Intelligent Robots: Sensing, Modeling and Planning Abbreviated Journal
Volume Issue Pages 164-179
Keywords
Abstract Dagstuhl Workshop
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Corporate Author Thesis
Publisher World Scientific Press Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN 9810231857 Medium
Area Expedition Conference
Notes DAG;IAM; Approved no
Call Number (down) IAM @ iam @ LBM1997b Serial 1563
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Author Josep Llados; Horst Bunke; Enric Marti
Title Finding rotational symmetries by cyclic string matching Type Journal Article
Year 1997 Publication Pattern recognition letters Abbreviated Journal PRL
Volume 18 Issue 14 Pages 1435-1442
Keywords Rotational symmetry; Reflectional symmetry; String matching
Abstract Symmetry is an important shape feature. In this paper, a simple and fast method to detect perfect and distorted rotational symmetries of 2D objects is described. The boundary of a shape is polygonally approximated and represented as a string. Rotational symmetries are found by cyclic string matching between two identical copies of the shape string. The set of minimum cost edit sequences that transform the shape string to a cyclically shifted version of itself define the rotational symmetry and its order. Finally, a modification of the algorithm is proposed to detect reflectional symmetries. Some experimental results are presented to show the reliability of the proposed algorithm
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Corporate Author Thesis
Publisher Elsevier Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes DAG;IAM; Approved no
Call Number (down) IAM @ iam @ LBM1997a Serial 1562
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Author Josep Llados; Horst Bunke; Enric Marti
Title Using cyclic string matching to find rotational and reflectional symmetric shapes Type Conference Article
Year 1996 Publication Dagstuhl Seminar on Modelling and Planning for Sensor–based Intelligent Robot Systems Abbreviated Journal
Volume Issue Pages
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Abstract
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Corporate Author Thesis
Publisher World Scientific Place of Publication Saarbrucken (Germany). Editor R.C. Bolles, H.B.H.N.
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes DAG;IAM Approved no
Call Number (down) IAM @ iam @ LBM1996 Serial 1564
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Author Gerard Lacey; Fernando Vilariño
Title Endoscopy system with motion sensors Type Patent
Year 2011 Publication US 2011/0032347 A1 Abbreviated Journal
Volume Issue Pages
Keywords
Abstract An endoscopy system (1) comprises an endoscope (2) with a camera (3) at its tip. The endoscope extends through an endoscope guide (4) for guiding movement of the endoscope and for measurement of its movement as it enters the body. The guide (4) comprises a generally conical body (5) having a through passage (105) through which the endoscope (2) extends. A motion sensor comprises an optical transmitter (7) and a detector (8) mounted alongside the passage (105) to measure the insertion-withdrawal linear motion and also rotation of the endoscope by the endoscopist's hand. The system (1) also comprises a flexure controller (10) having wheels operated by the endoscopist. The camera (3), the motion sensor (7/8), and the flexure controller (10) are all connected to a processor (11) which feeds a display.
Address Jacobson Holman PPLC; 400 Seventh Street, N.W. Suite 600; Whashington DC 20004 DC
Corporate Author USPTO Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area 800 Expedition Conference
Notes MV;SIAI Approved no
Call Number (down) IAM @ iam @ LaV2011 Serial 1703
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Author Dimosthenis Karatzas;Ch. Lioutas
Title Software Package Development for Electron Diffraction Image Analysis Type Conference Article
Year 1998 Publication Proceedings of the XIV Solid State Physics National Conference Abbreviated Journal
Volume Issue Pages
Keywords
Abstract
Address Ioannina, Greece
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
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ISSN ISBN Medium
Area Expedition Conference
Notes DAG Approved no
Call Number (down) IAM @ iam @ KaL1998 Serial 2045
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Author Aura Hernandez-Sabate; Debora Gil; Albert Teis
Title How Do Conservation Laws Define a Motion Suppression Score in In-Vivo Ivus Sequences? Type Conference Article
Year 2007 Publication Proc. IEEE Ultrasonics Symp Abbreviated Journal
Volume Issue Pages 2231-2234
Keywords validation standards; IVUS motion compensation; conservation laws.
Abstract Evaluation of arterial tissue biomechanics for diagnosis and treatment of cardiovascular diseases is an active research field in the biomedical imaging processing area. IntraVascular UltraSound (IVUS) is a unique tool for such assessment since it reflects tissue morphology and deformation. A proper quantification and visualization of both properties is hindered by vessel structures misalignments introduced by cardiac dynamics. This has encouraged development of IVUS motion compensation techniques. However, there is a lack of an objective evaluation of motion reduction ensuring a reliable clinical application This work reports a novel score, the Conservation of Density Rate (CDR), for validation of motion compensation in in-vivo pullbacks. Synthetic experiments validate the proposed score as measure of motion parameters accuracy; while results in in vivo pullbacks show its reliability in clinical cases.
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Publisher Place of Publication Editor
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Series Editor Series Title Abbreviated Series Title
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Area Expedition Conference
Notes IAM Approved no
Call Number (down) IAM @ iam @ HTG2007 Serial 1550
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Author Aura Hernandez-Sabate; Monica Mitiko; Sergio Shiguemi; Debora Gil
Title A validation protocol for assessing cardiac phase retrieval in IntraVascular UltraSound Type Conference Article
Year 2010 Publication Computing in Cardiology Abbreviated Journal
Volume 37 Issue Pages 899-902
Keywords
Abstract A good reliable approach to cardiac triggering is of utmost importance in obtaining accurate quantitative results of atherosclerotic plaque burden from the analysis of IntraVascular UltraSound. Although, in the last years, there has been an increase in research of methods for retrospective gating, there is no general consensus in a validation protocol. Many methods are based on quality assessment of longitudinal cuts appearance and those reporting quantitative numbers do not follow a standard protocol. Such heterogeneity in validation protocols makes faithful comparison across methods a difficult task. We propose a validation protocol based on the variability of the retrieved cardiac phase and explore the capability of several quality measures for quantifying such variability. An ideal detector, suitable for its application in clinical practice, should produce stable phases. That is, it should always sample the same cardiac cycle fraction. In this context, one should measure the variability (variance) of a candidate sampling with respect a ground truth (reference) sampling, since the variance would indicate how spread we are aiming a target. In order to quantify the deviation between the sampling and the ground truth, we have considered two quality scores reported in the literature: signed distance to the closest reference sample and distance to the right of each reference sample. We have also considered the residuals of the regression line of reference against candidate sampling. The performance of the measures has been explored on a set of synthetic samplings covering different cardiac cycle fractions and variabilities. From our simulations, we conclude that the metrics related to distances are sensitive to the shift considered while the residuals are robust against fraction and variabilities as far as one can establish a pair-wise correspondence between candidate and reference. We will further investigate the impact of false positive and negative detections in experimental data.
Address
Corporate Author Thesis
Publisher IEEE Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0276-6547 ISBN 978-1-4244-7318-2 Medium
Area Expedition Conference CINC
Notes IAM; Approved no
Call Number (down) IAM @ iam @ HSM2010 Serial 1551
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Author Aura Hernandez-Sabate; Petia Radeva; Antonio Tovar; Debora Gil
Title Vessel structures alignment by spectral analysis of ivus sequences Type Conference Article
Year 2006 Publication Proc. of CVII, MICCAI Workshop Abbreviated Journal
Volume Issue Pages 39-36
Keywords
Abstract Three-dimensional intravascular ultrasound (IVUS) allows to visualize and obtain volumetric measurements of coronary lesions through an exploration of the cross sections and longitudinal views of arteries. However, the visualization and subsequent morpho-geometric measurements in IVUS longitudinal cuts are subject to distortion caused by periodic image/vessel motion around the IVUS catheter. Usually, to overcome the image motion artifact ECG-gating and image-gated approaches are proposed, leading to slowing the pullback acquisition or disregarding part of IVUS data. In this paper, we argue that the image motion is due to 3-D vessel geometry as well as cardiac dynamics, and propose a dynamic model based on the tracking of an elliptical vessel approximation to recover the rigid transformation and align IVUS images without loosing any IVUS data. We report an extensive validation with synthetic simulated data and in vivo IVUS sequences of 30 patients achieving an average reduction of the image artifact of 97% in synthetic data and 79% in real-data. Our study shows that IVUS alignment improves longitudinal analysis of the IVUS data and is a necessary step towards accurate reconstruction and volumetric measurements of 3-D IVUS.
Address
Corporate Author Thesis
Publisher Place of Publication Copenhaguen (Denmark), Editor
Language Summary Language Original Title
Series Editor Series Title 1st International Wokshop on Computer Vision for Intravascular and Intracardiac Imaging (CVII’06) Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes IAM; MILAB Approved no
Call Number (down) IAM @ iam @ HRT2006 Serial 1552
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Author Aura Hernandez-Sabate; David Rotger; Debora Gil
Title Image-based ECG sampling of IVUS sequences Type Conference Article
Year 2008 Publication Proc. IEEE Ultrasonics Symp. IUS 2008 Abbreviated Journal
Volume Issue Pages 1330-1333
Keywords Longitudinal Motion; Image-based ECG-gating; Fourier analysis
Abstract Longitudinal motion artifacts in IntraVascular UltraSound (IVUS) sequences hinders a properly 3D reconstruction and vessel measurements. Most of current techniques base on the ECG signal to obtain a gated pullback without the longitudinal artifact by using a specific hardware or the ECG signal itself. The potential of IVUS images processing for phase retrieval still remains little explored. In this paper, we present a fast forward image-based algorithm to approach ECG sampling. Inspired on the fact that maximum and minimum lumen areas are related to end-systole and end-diastole, our cardiac phase retrieval is based on the analysis of tissue density of mass along the sequence. The comparison between automatic and manual phase retrieval (0.07 ± 0.07 mm. of error) encourages a deep validation contrasting with ECG signals.
Address Beijing (China)
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes IAM;MILAB Approved no
Call Number (down) IAM @ iam @ HRG2008 Serial 1553
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Author Alberto Hidalgo; Ferran Poveda; Enric Marti;Debora Gil;Albert Andaluz; Francesc Carreras; Manuel Ballester
Title Evidence of continuous helical structure of the cardiac ventricular anatomy assessed by diffusion tensor imaging magnetic resonance multiresolution tractography Type Journal Article
Year 2012 Publication European Radiology Abbreviated Journal ECR
Volume 3 Issue 1 Pages 361-362
Keywords
Abstract Deep understanding of myocardial structure linking morphology and func- tion of the heart would unravel crucial knowledge for medical and surgical clinical procedures and studies. Diffusion tensor MRI provides a discrete measurement of the 3D arrangement of myocardial fibres by the observation of local anisotropic
diffusion of water molecules in biological tissues. In this work, we present a multi- scale visualisation technique based on DT-MRI streamlining capable of uncovering additional properties of the architectural organisation of the heart. Methods and Materials: We selected the John Hopkins University (JHU) Canine Heart Dataset, where the long axis cardiac plane is aligned with the scanner’s Z- axis. Their equipment included a 4-element passed array coil emitting a 1.5 T. For DTI acquisition, a 3D-FSE sequence is apply. We used 200 seeds for full-scale tractography, while we applied a MIP mapping technique for simplified tractographic reconstruction. In this case, we reduced each DTI 3D volume dimensions by order- two magnitude before streamlining.
Our simplified tractographic reconstruction method keeps the main geometric features of fibres, allowing for an easier identification of their global morphological disposition, including the ventricular basal ring. Moreover, we noticed a clearly visible helical disposition of the myocardial fibres, in line with the helical myocardial band ventricular structure described by Torrent-Guasp. Finally, our simplified visualisation with single tracts identifies the main segments of the helical ventricular architecture.
DT-MRI makes possible the identification of a continuous helical architecture of the myocardial fibres, which validates Torrent-Guasp’s helical myocardial band ventricular anatomical model.
Address Viena, Austria
Corporate Author Thesis
Publisher Springer Link Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1869-4101 ISBN Medium
Area Expedition Conference
Notes IAM Approved no
Call Number (down) IAM @ iam @ HPM2012 Serial 1858
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Author Aura Hernandez-Sabate; Debora Gil; David Roche; Monica M. S. Matsumoto; Sergio S. Furuie
Title Inferring the Performance of Medical Imaging Algorithms Type Conference Article
Year 2011 Publication 14th International Conference on Computer Analysis of Images and Patterns Abbreviated Journal
Volume 6854 Issue Pages 520-528
Keywords Validation, Statistical Inference, Medical Imaging Algorithms.
Abstract Evaluation of the performance and limitations of medical imaging algorithms is essential to estimate their impact in social, economic or clinical aspects. However, validation of medical imaging techniques is a challenging task due to the variety of imaging and clinical problems involved, as well as, the difficulties for systematically extracting a reliable solely ground truth. Although specific validation protocols are reported in any medical imaging paper, there are still two major concerns: definition of standardized methodologies transversal to all problems and generalization of conclusions to the whole clinical data set.
We claim that both issues would be fully solved if we had a statistical model relating ground truth and the output of computational imaging techniques. Such a statistical model could conclude to what extent the algorithm behaves like the ground truth from the analysis of a sampling of the validation data set. We present a statistical inference framework reporting the agreement and describing the relationship of two quantities. We show its transversality by applying it to validation of two different tasks: contour segmentation and landmark correspondence.
Address Sevilla
Corporate Author Thesis
Publisher Springer-Verlag Berlin Heidelberg Place of Publication Berlin Editor Pedro Real; Daniel Diaz-Pernil; Helena Molina-Abril; Ainhoa Berciano; Walter Kropatsch
Language Summary Language Original Title
Series Editor Series Title L Abbreviated Series Title LNCS
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference CAIP
Notes IAM; ADAS Approved no
Call Number (down) IAM @ iam @ HGR2011 Serial 1676
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Author Aura Hernandez-Sabate; Debora Gil; Petia Radeva
Title On the usefulness of supervised learning for vessel border detection in IntraVascular Imaging Type Conference Article
Year 2005 Publication Proceeding of the 2005 conference on Artificial Intelligence Research and Development Abbreviated Journal
Volume Issue Pages 67-74
Keywords classification; vessel border modelling; IVUS
Abstract IntraVascular UltraSound (IVUS) imaging is a useful tool in diagnosis of cardiac diseases since sequences completely show the morphology of coronary vessels. Vessel borders detection, especially the external adventitia layer, plays a central role in morphological measures and, thus, their segmentation feeds development of medical imaging techniques. Deterministic approaches fail to yield optimal results due to the large amount of IVUS artifacts and vessel borders descriptors. We propose using classification techniques to learn the set of descriptors and parameters that best detect vessel borders. Statistical hypothesis test on the error between automated detections and manually traced borders by 4 experts show that our detections keep within inter-observer variability.
Address
Corporate Author Thesis
Publisher IOS Press Place of Publication Amsterdam, The Netherlands Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes IAM;MILAB Approved no
Call Number (down) IAM @ iam @ HGR2005c Serial 1549
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