Filters








15,125 Hits in 8.2 sec

An Elastic Energy Minimization Framework for Mean Contour Calculation [article]

Jozsef Molnar, Michael Barbier, Winnok H. De Vos, Peter Horvath
2019 arXiv   pre-print
In this paper we propose a contour mean calculation and interpolation method designed for averaging manual delineations of objects performed by experts and interpolate 3D layer stack images.  ...  To identify the optimal re-parameterization system and proper centroid we use double energy minimization realized in a variational framework.  ...  To develop a framework for efficient contour mean calculation, first we assess some natural conditions to be fulfilled by any model developed for this purpose: A) Keep all visible information (relative  ... 
arXiv:1901.02823v1 fatcat:n3edso2tdfh7rdnjyo52kte6ka

Shadow Segmentation in SAS and SAR Using Bayesian Elastic Contours

Darshan Bryner, Anuj Srivastava
2013 2013 IEEE Conference on Computer Vision and Pattern Recognition Workshops  
We present a variational framework for naturally incorporating prior shape knowledge in guidance of active contours for boundary extraction in images.  ...  Since shadow shapes can vary under approximately affine transformation with different target range and aspect angle, we incorporate an affine-invariant, elastic shape prior based on the shape analysis  ...  The variational framework for contour evolution remains the same as that of earlier methods, except that the shape prior term now comes from either of the two elastic shape models.  ... 
doi:10.1109/cvprw.2013.63 dblp:conf/cvpr/BrynerS13 fatcat:bnvpv6njprg2vmzeof5por57ai

Bayesian Active Contours with Affine-Invariant, Elastic Shape Prior

Darshan Bryner, Anuj Srivastava
2014 2014 IEEE Conference on Computer Vision and Pattern Recognition  
The active contour is then driven by the true gradient of a total energy composed of a data term, a smoothing term, and an affine-invariant shape-prior term.  ...  Using an elastic, affine-invariant shape modeling of planar curves, we propose an active contour algorithm in which the training and test shapes can be at arbitrary affine transformations, and the resulting  ...  In our work we compute a true gradient descent flow for energy minimization [17] ; that is, for each energy functional in the active contour model, we compute its gradient with respect to the same (L  ... 
doi:10.1109/cvpr.2014.47 dblp:conf/cvpr/BrynerS14 fatcat:gpapueiyczfttn7ihbcmxsuruu

Bayesian Active Contours with Affine-Invariant Elastic Shape Prior [chapter]

Darshan Bryner, Anuj Srivastava
2015 Current Trends in Bayesian Methodology with Applications  
The active contour is then driven by the true gradient of a total energy composed of a data term, a smoothing term, and an affine-invariant shape-prior term.  ...  Using an elastic, affine-invariant shape modeling of planar curves, we propose an active contour algorithm in which the training and test shapes can be at arbitrary affine transformations, and the resulting  ...  In our work we compute a true gradient descent flow for energy minimization [17] ; that is, for each energy functional in the active contour model, we compute its gradient with respect to the same (L  ... 
doi:10.1201/b18502-8 fatcat:voaqm376ibbpdgd7u525vfmszi

A Review on Role of Active Contour Model in Image Segmentation Applications

Jaiswal R.S, Sarode M.V
2017 IJARCCE  
based on curve evolution and energy minimization techniques.  ...  Active contours combine underlying information with high-level prior knowledge to achieve automatic segmentation for complex objects.  ...  The provision of a means for specifying these external energy factors allows a degree of flexibility in the use of the active contour model for finding accurate contours in noisy or busy image areas.  ... 
doi:10.17148/ijarcce.2017.65129 fatcat:lztkrog5ejbqfhpow752oyqojm

DETECTION OF LUMEN-INTIMA INTERFACE MOTION OF PERIPHERAL ARTERY FOR MEASUREMENT OF ELASTICITY PROFILE

O. Laouini, F. Essafi, L.Bressollette, E.Ben Braiek
2018 Zenodo  
Results for these parameters revealed a new technique to study the decrease of vessel wall elasticity.  ...  The proceeding of obtained ultrasonic B-mode images consists in Semi-Automated Endoluminal Contour Detection using serval active contour segmentation methods and geometrical measurements in order to evaluate  ...  This model [4] tries to stop the evolution of the curve with an energy minimization approach rather than using an edge-stopping function.  ... 
doi:10.5281/zenodo.1567203 fatcat:eodgs6uuyvcgpeyifwkknfdgre

An Elastic Energy Minimization Framework for Mean Surface Calculation [article]

Jozsef Molnar, Peter Horvath
2019 arXiv   pre-print
to determine the minimizing diffeomorphism and b) the proper centroid calculation for the surface mean calculation are presented.  ...  As the continuation of the contour mean calculation - designed for averaging the manual delineations of 3D layer stack images - in this paper, the most important equations: a) the reparameterization equations  ...  centroid calculation for the surface mean calculation are presented.  ... 
arXiv:1907.13557v1 fatcat:mkiwbcfkmreolkkl57kgfw3ome

Segmentation of 2-D and 3-D objects from MRI volume data using constrained elastic deformations of flexible Fourier contour and surface models

Gábor Székely, András Kelemen, Christian Brechbühler, Guido Gerig
1996 Medical Image Analysis  
Usually the segmentation process is divided into an initial placement of the mean model and an elastic deformation restricted to the model variability.  ...  Flexible parametric shape models are represented by a parameter vector describing the mean contour and by a set of eig ¦ enmodes of the parameters characterizing § the shape variation.  ...  ACKNOWLEDGEMENTS The authors thank Ron Kikinis (Brigham and Women's Hospital, Harvard Medical School, Boston) for organizing the MR acquisitions and for discussions in regard to the clinical needs for  ... 
doi:10.1016/s1361-8415(01)80003-7 pmid:9873919 fatcat:ffh2huikovbjfeoy65zyz6cc4i

DETECTION OF LUMEN-INTIMA INTERFACE MOTION OF PERIPHERAL ARTERY FOR MEASUREMENT OF ELASTICITY PROFILE

O. Laouini, F. Essafi, L.Bressollette, E.Ben Braiek
2018 Zenodo  
Results for these parameters revealed a new technique to study the decrease of vessel wall elasticity.  ...  The proceeding of obtained ultrasonic B-mode images consists in Semi-Automated Endoluminal Contour Detection using serval active contour segmentation methods and geometrical measurements in order to evaluate  ...  center point "centroid" for each sequence of the crossectional frames. calculations of thearterials elastic properties is closely linked to arterial wall contour that we have materialized in different  ... 
doi:10.5281/zenodo.1566548 fatcat:xjt25doqebgaln3oe4dnemgcga

Numerical Solutions of the Von Karman Equations for a Thin Plate

Pedro Patrício da Silva, Werner Krauth
1997 International Journal of Modern Physics C  
In this paper, we present an algorithm for the solution of the von Karman equations of elasticity theory and related problems.  ...  We illustrate the power of the method by numerical calculations of pinched or compressed plates subject to fixed boundaries.  ...  The physical problem discussed so far consists in an elastic plate, whose zero-energy configuration is the unit square. We impose a cylindrical contour on two opposing sides.  ... 
doi:10.1142/s0129183197000357 fatcat:ot2dysesgjelznb7fqxzxqldoi

In Vivo Investigation of the Effectiveness of a Hyper-viscoelastic Model in Simulating Brain Retraction

Ping Li, Weiwei Wang, Chenxi Zhang, Yong An, Zhijian Song
2016 Scientific Reports  
To explore its effectiveness, we then applied this framework to an in vivo brain retraction simulation.  ...  Our experimental results showed that the hyperviscoelastic XFEM framework is capable of simulating intraoperative brain retraction and improving the navigation accuracy of an image-guided neurosurgery  ...  (mean ± S.D.)), while the average calculation time of the linear elastic XFEM model (35.5 ± 4.5 s (mean ± S.D.)) is longer than that of the hyper-viscoelastic XFEM model (25.5 ± 4.5 s (mean ± S.D.)).  ... 
doi:10.1038/srep28654 pmid:27387301 pmcid:PMC4937391 fatcat:vwoamy56krav5exlp6o67qj54i

Deformable Models and Optimal Mass Transportation for Processing of DCE-MRI 2D Images

V. Russo, J. Lanini, N. Dubbini
2014 IFAC Proceedings Volumes  
Active Contours provide the automatical contour's depiction of a deformable object by minimizing an energy cost functional; Optimal Mass Transportation allows to tracking a deformable object by minimizing  ...  In this work we present a combined approach based on the Active Contours framework and on the Optimal Mass Transportation for the automatic depicting and tracking of deformable objects.  ...  A physicist might interpret the deformable contours as a set of elastic elements able to change their position due to the application of forces: by minimizing the energy functional, it is possible to reach  ... 
doi:10.3182/20140824-6-za-1003.01598 fatcat:pvxkh3bpk5chjpfl6lecvxqcgi

Thermodynamic Modeling of the Statistics of Cell Spreading on Ligand-Coated Elastic Substrates

Eoin McEvoy, Siamak S. Shishvan, Vikram S. Deshpande, J. Patrick McGarry
2018 Biophysical Journal  
Furthermore, elastic free energy induced by substrate deformation lowers the probability of observing a highly spread cell, and, consequentially, lower cell tractions affect the assembly of focal adhesions  ...  of an experiment predicts a single outcome).  ...  FIGURE 3 3 Contour plots for predicted mean spread area (a) and mean cell AR (b) in the r col À E sub space.  ... 
doi:10.1016/j.bpj.2018.11.007 pmid:30527450 pmcid:PMC6301989 fatcat:gct5pnlvajco7d4fpici5czmiy

A complete system for head tracking using motion-based particle filter and randomly perturbed active contour

N. Bouaynaya, Dan Schonfeld, Amir Said, John G. Apostolopoulos
2005 Image and Video Communications and Processing 2005  
In the second part of the paper, we refine the tracking output from a parametric sample to an elastic contour around the object.  ...  Many real world applications in computer and multimedia such as augmented reality and environmental imaging require an elastic accurate contour around a tracked object.  ...  We want to minimize the total energy.  ... 
doi:10.1117/12.587244 dblp:conf/eiivcp/BouaynayaS05 fatcat:nnq635phqzgirfqu6ju27gqqce

Left Ventricular Endocardium Tracking by Fusion of Biomechanical and Deformable Models

Hussin Ketout, Jason Gu
2014 Computational and Mathematical Methods in Medicine  
The strain energy functions are defined in two user subroutines for active and passive phases. Average fusion technique is used to fuse the BM and deformable model contours.  ...  This paper presents a framework for tracking left ventricular (LV) endocardium through 2D echocardiography image sequence.  ...  Snake is modeled as parametric curve that evolves into a position where its energy functional is minimized.  ... 
doi:10.1155/2014/302458 pmid:24587814 pmcid:PMC3918705 fatcat:3yh7upkr3vhdlakzmwhnbhe6rq
« Previous Showing results 1 — 15 out of 15,125 results