|
Records |
Links |
|
Author |
Debora Gil; Petia Radeva |
|
|
Title |
Extending anisotropic operators to recover smooth shapes |
Type |
Journal Article |
|
Year |
2005 |
Publication |
Computer Vision and Image Understanding |
Abbreviated Journal |
|
|
|
Volume |
99 |
Issue |
1 |
Pages |
110-125 |
|
|
Keywords |
Contour completion; Functional extension; Differential operators; Riemmanian manifolds; Snake segmentation |
|
|
Abstract |
Anisotropic differential operators are widely used in image enhancement processes. Recently, their property of smoothly extending functions to the whole image domain has begun to be exploited. Strong ellipticity of differential operators is a requirement that ensures existence of a unique solution. This condition is too restrictive for operators designed to extend image level sets: their own functionality implies that they should restrict to some vector field. The diffusion tensor that defines the diffusion operator links anisotropic processes with Riemmanian manifolds. In this context, degeneracy implies restricting diffusion to the varieties generated by the vector fields of positive eigenvalues, provided that an integrability condition is satisfied. We will use that any smooth vector field fulfills this integrability requirement to design line connection algorithms for contour completion. As application we present a segmenting strategy that assures convergent snakes whatever the geometry of the object to be modelled is. |
|
|
Address |
|
|
|
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 |
1077-3142 |
ISBN |
|
Medium |
|
|
|
Area |
|
Expedition |
|
Conference |
|
|
|
Notes |
IAM;MILAB |
Approved |
no |
|
|
Call Number |
IAM @ iam @ GIR2005 |
Serial |
1530 |
|
Permanent link to this record |
|
|
|
|
Author |
Debora Gil; Petia Radeva |
|
|
Title |
Shape Restoration via a Regularized Curvature Flow |
Type |
Journal Article |
|
Year |
2004 |
Publication |
Journal of Mathematical Imaging and Vision |
Abbreviated Journal |
|
|
|
Volume |
21 |
Issue |
3 |
Pages |
205-223 |
|
|
Keywords |
|
|
|
Abstract |
Any image filtering operator designed for automatic shape restoration should satisfy robustness (whatever the nature and degree of noise is) as well as non-trivial smooth asymptotic behavior. Moreover, a stopping criterion should be determined by characteristics of the evolved image rather than dependent on the number of iterations. Among the several PDE based techniques, curvature flows appear to be highly reliable for strongly noisy images compared to image diffusion processes.
In the present paper, we introduce a regularized curvature flow (RCF) that admits non-trivial steady states. It is based on a measure of the local curve smoothness that takes into account regularity of the curve curvature and serves as stopping term in the mean curvature flow. We prove that this measure decreases over the orbits of RCF, which endows the method with a natural stop criterion in terms of the magnitude of this measure. Further, in its discrete version it produces steady states consisting of piece-wise regular curves. Numerical experiments made on synthetic shapes corrupted with different kinds of noise show the abilities and limitations of each of the current geometric flows and the benefits of RCF. Finally, we present results on real images that illustrate the usefulness of the present approach in practical applications. |
|
|
Address |
|
|
|
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 @ GiR2004c |
Serial |
1532 |
|
Permanent link to this record |
|
|
|
|
Author |
Debora Gil; Oriol Rodriguez-Leor; Petia Radeva; J. Mauri |
|
|
Title |
Myocardial Perfusion Characterization From Contrast Angiography Spectral Distribution |
Type |
Journal Article |
|
Year |
2008 |
Publication |
IEEE Transactions on Medical Imaging |
Abbreviated Journal |
|
|
|
Volume |
27 |
Issue |
5 |
Pages |
641-649 |
|
|
Keywords |
Contrast angiography; myocardial perfusion; spectral analysis. |
|
|
Abstract |
Despite recovering a normal coronary flow after acute myocardial infarction, percutaneous coronary intervention does not guarantee a proper perfusion (irrigation) of the infarcted area. This damage in microcirculation integrity may detrimentally affect the patient survival. Visual assessment of the myocardium opacification in contrast angiography serves to define a subjective score of the microcirculation integrity myocardial blush analysis (MBA). Although MBA correlates with patient prognosis its visual assessment is a very difficult task that requires of a highly expertise training in order to achieve a good intraobserver and interobserver agreement. In this paper, we provide objective descriptors of the myocardium staining pattern by analyzing the spectrum of the image local statistics. The descriptors proposed discriminate among the different phenomena observed in the angiographic sequence and allow defining an objective score of the myocardial perfusion. |
|
|
Address |
|
|
|
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 @ GRR2008 |
Serial |
1541 |
|
Permanent link to this record |
|
|
|
|
Author |
Oriol Rodriguez-Leor; A. Carol; H. Tizon; Eduard Fernandez-Nofrerias; J. Mauri; Vicente del Valle; Debora Gil; Aura Hernandez-Sabate; Petia Radeva |
|
|
Title |
Model estadístic-determinístic per la segmentació de l adventicia en imatges d ecografía intracoronaria |
Type |
Journal Article |
|
Year |
2005 |
Publication |
Rev Societat Catalana Cardiologia |
Abbreviated Journal |
|
|
|
Volume |
5 |
Issue |
|
Pages |
41 |
|
|
Keywords |
|
|
|
Abstract |
|
|
|
Address |
|
|
|
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 @ RCT2005 |
Serial |
1637 |
|
Permanent link to this record |
|
|
|
|
Author |
Oriol Rodriguez-Leor; J. Mauri; Eduard Fernandez-Nofrerias; C. Garcia; R. Villuendas; Vicente del Valle; Debora Gil; Petia Radeva |
|
|
Title |
Reconstruction of a spatio-temporal model of the intima layer from intravascular ultrasound sequences |
Type |
Journal Article |
|
Year |
2003 |
Publication |
European Heart Journal |
Abbreviated Journal |
|
|
|
Volume |
|
Issue |
|
Pages |
|
|
|
Keywords |
|
|
|
Abstract |
|
|
|
Address |
|
|
|
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 |
ESC Congress |
|
|
Notes |
IAM;MILAB |
Approved |
no |
|
|
Call Number |
IAM @ iam @ RMF2003c |
Serial |
1641 |
|
Permanent link to this record |
|
|
|
|
Author |
Oriol Rodriguez-Leor; J. Mauri; Eduard Fernandez-Nofrerias; Antonio Tovar; Vicente del Valle; Aura Hernandez-Sabate; Debora Gil; Petia Radeva |
|
|
Title |
Utilización de la Estructura de los Campos Vectoriales para la Detección de la Adventicia en Imágenes de Ecografía Intracoronaria |
Type |
Journal Article |
|
Year |
2004 |
Publication |
Revista Internacional de Enfermedades Cardiovasculares Revista Española de Cardiología |
Abbreviated Journal |
|
|
|
Volume |
57 |
Issue |
2 |
Pages |
100 |
|
|
Keywords |
|
|
|
Abstract |
|
|
|
Address |
|
|
|
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 |
SEC |
|
|
Notes |
IAM;MILAB |
Approved |
no |
|
|
Call Number |
IAM @ iam @ RMF2004 |
Serial |
1642 |
|
Permanent link to this record |
|
|
|
|
Author |
Misael Rosales; Petia Radeva; Oriol Rodriguez-Leor; Debora Gil |
|
|
Title |
Modelling of image-catheter motion for 3-D IVUS |
Type |
Journal Article |
|
Year |
2009 |
Publication |
Medical image analysis |
Abbreviated Journal |
MIA |
|
|
Volume |
13 |
Issue |
1 |
Pages |
91-104 |
|
|
Keywords |
Intravascular ultrasound (IVUS); Motion estimation; Motion decomposition; Fourier |
|
|
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 |
|
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 @ RRR2009 |
Serial |
1646 |
|
Permanent link to this record |
|
|
|
|
Author |
Oriol Pujol; Debora Gil; Petia Radeva |
|
|
Title |
Fundamentals of Stop and Go active models |
Type |
Journal Article |
|
Year |
2005 |
Publication |
Image and Vision Computing |
Abbreviated Journal |
|
|
|
Volume |
23 |
Issue |
8 |
Pages |
681-691 |
|
|
Keywords |
Deformable models; Geodesic snakes; Region-based segmentation |
|
|
Abstract |
An efficient snake formulation should conform to the idea of picking the smoothest curve among all the shapes approximating an object of interest. In current geodesic snakes, the regularizing curvature also affects the convergence stage, hindering the latter at concave regions. In the present work, we make use of characteristic functions to define a novel geodesic formulation that decouples regularity and convergence. This term decoupling endows the snake with higher adaptability to non-convex shapes. Convergence is ensured by splitting the definition of the external force into an attractive vector field and a repulsive one. In our paper, we propose to use likelihood maps as approximation of characteristic functions of object appearance. The better efficiency and accuracy of our decoupled scheme are illustrated in the particular case of feature space-based segmentation. |
|
|
Address |
|
|
|
Corporate Author |
|
Thesis |
|
|
|
Publisher |
Butterworth-Heinemann |
Place of Publication |
Newton, MA, USA |
Editor |
|
|
|
Language |
|
Summary Language |
|
Original Title |
|
|
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
0262-8856 |
ISBN |
|
Medium |
|
|
|
Area |
|
Expedition |
|
Conference |
|
|
|
Notes |
IAM;MILAB;HuPBA |
Approved |
no |
|
|
Call Number |
IAM @ iam @ PGR2005 |
Serial |
1629 |
|
Permanent link to this record |
|
|
|
|
Author |
Oriol Rodriguez-Leor; J. Mauri; Eduard Fernandez-Nofrerias; M. Gomez; Antonio Tovar; L. Cano; C. Diego; Carme Julia; Vicente del Valle; Debora Gil; Petia Radeva |
|
|
Title |
Ecografia Intracoronaria: Segmentacio Automatica de area de la llum |
Type |
Journal |
|
Year |
2002 |
Publication |
Revista Societat Catalana de Cardiologia |
Abbreviated Journal |
|
|
|
Volume |
4 |
Issue |
4 |
Pages |
42 |
|
|
Keywords |
|
|
|
Abstract |
|
|
|
Address |
Barcelona |
|
|
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 |
XIVe Congres de la Societat Catalana de Cardiologia |
|
|
Notes |
MILAB;IAM |
Approved |
no |
|
|
Call Number |
BCNPCL @ bcnpcl @ RMF2002 |
Serial |
435 |
|
Permanent link to this record |
|
|
|
|
Author |
Oriol Rodriguez-Leor; J. Mauri; Eduard Fernandez-Nofrerias; Antonio Tovar; Vicente del Valle; Aura Hernandez-Sabate; Debora Gil; Petia Radeva |
|
|
Title |
Utilizacion de la estructura de los campos vectoriales para la deteccion de la Adventicia en imagenes de Ecografia Intracoronaria |
Type |
Journal |
|
Year |
2004 |
Publication |
Revista Española de Cardiología |
Abbreviated Journal |
REC |
|
|
Volume |
57 |
Issue |
2 |
Pages |
100 |
|
|
Keywords |
|
|
|
Abstract |
|
|
|
Address |
|
|
|
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 |
SEC |
|
|
Notes |
MILAB;IAM |
Approved |
no |
|
|
Call Number |
BCNPCL @ bcnpcl @ RMF2004 |
Serial |
566 |
|
Permanent link to this record |