Search for: variational-framework
0.005 seconds

    Joint edge detection and motion estimation of cardiac MR image sequence by a phase field method

    , Article Computers in Biology and Medicine ; Volume 40, Issue 1 , 2010 , Pages 21-28 ; 00104825 (ISSN) Eslami, A ; Jahed, M ; Preusser, T ; Sharif University of Technology
    In this paper a variational framework for joint segmentation and motion estimation is employed for inspecting heart in Cine MRI sequences. A functional including Mumford-Shah segmentation and optical flow based dense motion estimation is approximated using the phase-field technique. The minimizer of the functional provides an optimum motion field and edge set by considering both spatial and temporal discontinuities. Exploiting calculus of variation principles, multiple partial differential equations associated with the Euler-Lagrange equations of the functional are extracted, first. Next, the finite element method is used to discretize the resulting PDEs for numerical solution. Several... 

    A multiscale phase field method for joint segmentation-rigid registration application to motion estimation of human knee joint

    , Article Biomedical Engineering - Applications, Basis and Communications ; Volume 23, Issue 6 , 2011 , Pages 445-456 ; 10162372 (ISSN) Eslami, A ; Esfandiarpour, F ; Shakourirad, A ; Farahmand, F ; Sharif University of Technology
    Image based registration of rigid objects has been frequently addressed in the literature to obtain an object's motion parameters. In this paper, a new approach of joint segmentation-rigid registration, within the variational framework of the phase field approximation of the Mumford-Shah's functional, is proposed. The defined functional consists of two Mumford-Shah equations, extracting the discontinuity set of the reference and target images due to a rigid spatial transformation. Multiscale minimization of the proposed functional after finite element discretization provided a sub-pixel, robust algorithm for edge extraction as well as edge based rigid registration. The implementation...