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Author Aura Hernandez-Sabate; Petia Radeva; Antonio Tovar; Debora Gil edit   pdf
url  openurl
  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 (up)  
  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 IAM @ iam @ HRT2006 Serial 1552  
Permanent link to this record
 

 
Author Aura Hernandez-Sabate; Debora Gil; J. Mauri; Petia Radeva edit   pdf
openurl 
  Title Reducing cardiac motion in IVUS sequences Type Conference Article
  Year 2006 Publication Proceeding of Computers in Cardiology Abbreviated Journal  
  Volume 33 Issue Pages 685-688  
  Keywords  
  Abstract Cardiac vessel displacement is a main artifact in IVUS sequences. It hinders visualization of the main structures in an appropriate orientation and alignment and affects extracting vessel measurements. In this paper, we present a novel approach for image sequence alignment based on spectral analysis, which removes rigid dynamics, preserving at the same time the vessel geometry. First, we suppress the translation by taking, for each frame, the center of mass of the image as origin of coordinates. In polar coordinates with such point as origin, the rotation appears as a horizontal displacement. The translation induces a phase shift in the Fourier coefficients of two consecutive polar images. We estimate the phase by adjusting a regression plane to the phases of the principal frequencies. Experiments show that the presented strategy suppress cardiac motion regardless of the acquisition device. 1.  
  Address (up)  
  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 IAM @ iam @ HGM2006a Serial 1554  
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Author Aura Hernandez-Sabate; Debora Gil; Petia Radeva; E.N.Nofrerias edit   pdf
doi  openurl
  Title Anisotropic processing of image structures for adventitia detection in intravascular ultrasound images Type Conference Article
  Year 2004 Publication Proc. Computers in Cardiology Abbreviated Journal  
  Volume 31 Issue Pages 229-232  
  Keywords  
  Abstract The adventitia layer appears as a weak edge in IVUS images with a non-uniform grey level, which difficulties its detection. In order to enhance edges, we apply an anisotropic filter that homogenizes the grey level along the image significant structures (ridges, valleys and edges). A standard edge detector applied to the filtered image yields a set of candidate points prone to be unconnected. The final model is obtained by interpolating the former line segments along the tangent direction to the level curves of the filtered image with an anisotropic contour closing technique based on functional extension principles  
  Address (up)  
  Corporate Author Thesis  
  Publisher Place of Publication Chicago (USA) 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 IAM @ iam @ HGR2004 Serial 1555  
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Author Josep Llados;Horst Bunke; Enric Marti edit  url
isbn  openurl
  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  
  Address (up)  
  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 IAM @ iam @ LBM1997b Serial 1563  
Permanent link to this record
 

 
Author Josep Llados; Horst Bunke; Enric Marti edit  doi
openurl 
  Title Using cyclic string matching to find rotational and reflectional symmetric shapes Type Conference Article
  Year 1996 Publication Intelligent Robots: Sensing, Modeling and Planning (Dagstuhl Workshop) Abbreviated Journal  
  Volume Issue Pages 164-179  
  Keywords  
  Abstract  
  Address (up)  
  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 IAM @ iam @ LBM1996 Serial 1564  
Permanent link to this record
 

 
Author Josep Llados; Horst Bunke; Enric Marti edit   pdf
openurl 
  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.  
  Address (up)  
  Corporate Author Thesis  
  Publisher Place of Publication Cordoba 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 IAM @ iam @ LIM1995 Serial 1565  
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Author Josep Llados; Jaime Lopez-Krahe; Gemma Sanchez; Enric Marti edit  openurl
  Title Interprétation de cartes et plans par mise en correspondance de graphes de attributs Type Conference Article
  Year 2000 Publication 12 Congrès Francophone AFRIF–AFIA Abbreviated Journal  
  Volume 3 Issue Pages 225-234  
  Keywords  
  Abstract  
  Address (up)  
  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 RFIA  
  Notes DAG;IAM Approved no  
  Call Number IAM @ iam @ LLS2000 Serial 1567  
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Author Josep Llados; Enric Marti edit  openurl
  Title Playing with error-tolerant subgraph isomorphism in line drawings Type Conference Article
  Year 1997 Publication VII National Symposium on Pattern Recognition and image Analysis Abbreviated Journal  
  Volume Issue Pages  
  Keywords  
  Abstract  
  Address (up)  
  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 DAG;IAM; Approved no  
  Call Number IAM @ iam @ LlM1997 Serial 1570  
Permanent link to this record
 

 
Author Josep Llados; Enric Marti; Jordi Regincos edit  openurl
  Title Interpretación de diseños a mano alzada como técnica de entrada a un sistema CAD en un ámbito de arquitectura Type Conference Article
  Year 1993 Publication III National Conference on Computer Graphics (CEIG'93) Abbreviated Journal  
  Volume 1 Issue Pages 33-46  
  Keywords  
  Abstract En los últimos años, se ha introducido ámpliamente el uso de los sistemas CAD en dominios relacionados con la arquitectura. Dichos sistemas CAD son muy útiles para el arquitecto en el diseño de planos de plantas de edificios. Sin embargo, la utilización eficiente de un CAD requiere un tiempo de aprendizaje, en especial, en la etapa de creación y edición del diseño. Además, una vez familiarizado con un CAD, el arquitecto debe adaptarse a la simbología que éste le permite que, en algunos casos puede ser poco flexible.Con esta motivación, se propone una técnica alternativa de entrada de documentos en sistemas CAD. Dicha técnica se basa en el diseño del plano sobre papel mediante un dibujo lineal hecho a mano alzada a modo de boceto e introducido mediante scanner. Una vez interpretado este dibujo inicial e introducido en el CAD, el arquitecto sólo deber hacer sobre éste los retoques finales del documento.El sistema de entrada propuesto se compone de dos módulos principales: En primer lugar, la extracción de características (puntos característicos, rectas y arcos) de la imagen obtenida mediante scanner. En dicho módulo se aplican principalmente técnicas de procesamiento de imágenes obteniendo como resultado una representaci¢n del dibujo de entrada basada en grafos de atributos. El objetivo del segundo módulo es el de encontrar y reconocer las entidades integrantes del documento (puertas, mesas, etc.) en base a una biblioteca de símbolos definida en el sistema CAD. La implementación de dicho módulo se basa en técnicas de isomorfismo de grafos.El sistema propone una alternativa que permita, mediante el diseño a mano alzada, la introducción de la informaci¢n m s significativa del plano de forma rápida, sencilla y estandarizada por parte del usuario.  
  Address (up)  
  Corporate Author Thesis  
  Publisher Place of Publication Granada Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Medium  
  Area Expedition Conference CEIG  
  Notes DAG;IAM; Approved no  
  Call Number IAM @ iam @ LMR1993 Serial 1571  
Permanent link to this record
 

 
Author Josep Llados; Enric Marti edit   pdf
openurl 
  Title Interpretacio de dibuixos lineals mitjançant tècniques d isomorfisme entre grafs Type Conference Article
  Year 1995 Publication Trobada de Joves Investigadors Abbreviated Journal  
  Volume Issue Pages  
  Keywords  
  Abstract L’anàlisi de documents té com a objectiu la interpretació automàtica de documents impresos sobre paper, amb la finalitat d’obtenir una descripció simbòlica d’aquests, que permeti el seu emmagatzemament i posterior tractament computacional. Les tècniques basades en grafs relacionals d’atributs permeten representar de manera compacta la informació continguda en dibuixos lineals i mitjançant mecanismes d’isomorfisme entre grafs, reconèixer-hi certes estructures i d’aquesta manera, interpretar el document. En aquest treball es dóna una visió general de les tènciques de grafs aplicades al reconeixement visual d’objectes en problemes d’anàlisi de documents. Aquestes tècniques s’il·lustren amb un exemple de reconeixement de plànols dibuixats a mà alçada. Finalment es proposa la utilització de tècniques de Hough com a mecanisme per accelerar el procés de reconeixement aplicant un cert coneixement sobre el domini en el que es treballa  
  Address (up)  
  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 DAG;IAM Approved no  
  Call Number IAM @ iam @ LlM1995 Serial 1578  
Permanent link to this record
 

 
Author Josep Llados; Jaime Lopez-Krahe; Enric Marti edit   pdf
doi  openurl
  Title Hand drawn document understanding using the straight line Hough transform and graph matching Type Conference Article
  Year 1996 Publication Proceedings of the 13th International Pattern Recognition Conference (ICPR’96) Abbreviated Journal  
  Volume 2 Issue Pages 497-501  
  Keywords  
  Abstract This paper presents a system to understand hand drawn architectural drawings in a CAD environment. The procedure is to identify in a floor plan the building elements, stored in a library of patterns, and their spatial relationships. The vectorized input document and the patterns to recognize are represented by attributed graphs. To recognize the patterns as such, we apply a structural approach based on subgraph isomorphism techniques. In spite of their value, graph matching techniques do not recognize adequately those building elements characterized by hatching patterns, i.e. walls. Here we focus on the recognition of hatching patterns and develop a straight line Hough transform based method in order to detect the regions filled in with parallel straight fines. This allows not only to recognize filling patterns, but it actually reduces the computational load associated with the subgraph isomorphism computation. The result is that the document can be redrawn by editing all the patterns recognized  
  Address (up)  
  Corporate Author Thesis  
  Publisher Place of Publication Vienna , Austria 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 IAM @ iam @ LLM1996 Serial 1579  
Permanent link to this record
 

 
Author Josep Llados; Enric Marti; Jaime Lopez-Krahe edit   pdf
doi  openurl
  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.  
  Address (up)  
  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 DAG;IAM; Approved no  
  Call Number IAM @ iam @ LIM1999b Serial 1580  
Permanent link to this record
 

 
Author Enric Marti; Jordi Regincos;Jaime Lopez-Krahe; Juan J.Villanueva edit  openurl
  Title Interpretación de dibujos lineales a mano alzada como objetos 3D Type Conference Article
  Year 1992 Publication V Simposium Nacional de Reconocimiento de Formas y Análisis de Imágenes Abbreviated Journal  
  Volume Issue Pages  
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  Address (up)  
  Corporate Author Thesis  
  Publisher Place of Publication València 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;ISE Approved no  
  Call Number IAM @ iam @ MRL1992 Serial 1601  
Permanent link to this record
 

 
Author Enric Marti; Jordi Regincos; Jaime Lopez-Krahe edit  openurl
  Title Interpretación de Dibujos Lineales a Mano Alzada Representando Escenas Tridimensionales Type Conference Article
  Year 1991 Publication Primer Congreso Español de Informática. Abbreviated Journal  
  Volume Issue Pages  
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  Area Expedition Conference  
  Notes IAM Approved no  
  Call Number IAM @ iam @ MRL1991 Serial 1610  
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Author J. Mauri; Eduard Fernandez-Nofrerias; B. Garcia del Blanco; E. Iraculis; J.A. Gomez-Hospital; J. Comin; M.A. Sanchez Corral; F. Jara; A. Cequier; E. Esplugas; Debora Gil; J. Saludes; Petia Radeva; Ricardo Toledo; Juan J.Villanueva edit  openurl
  Title Moviment del vas en l anàlisi d imatges d ecografia intracoronària: un model matemàtic Type Conference Article
  Year 2000 Publication Congrés de la Societat Catalana de Cardiologia. Abbreviated Journal  
  Volume Issue Pages  
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  Area Expedition Conference  
  Notes IAM;RV;ISE;MILAB;ADAS Approved no  
  Call Number IAM @ iam @ MNG2000 Serial 1621  
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