Introduction Active Contour Models - Theory Implementation Results and Outlook Ballooning Snake Erika Tunyogi Feza Carlak Nicholas Popovic Manuel Werlberger SSIP 2006 July 7, 2006 (SSIP 2006) Snake July 7, 2006 1 / 16
Introduction Active Contour Models - Theory Implementation Results and Outlook Outline 1 Introduction 2 Active Contour Models - Theory 3 Implementation 4 Results and Outlook (SSIP 2006) Snake July 7, 2006 2 / 16
Introduction Active Contour Models - Theory Implementation Results and Outlook Overview 1 Introduction 2 Active Contour Models - Theory 3 Implementation 4 Results and Outlook (SSIP 2006) Snake July 7, 2006 3 / 16
Introduction Active Contour Models - Theory Implementation Results and Outlook Team Members Erika Tunyogi - Theoretician, Researcher Feza Carlak - Coordinator, Researcher Nicolas Popovic - Graphic and Web Page Designer Manuel Werlberger - Software Engineer (SSIP 2006) Snake July 7, 2006 4 / 16
Introduction Active Contour Models - Theory Implementation Results and Outlook Motivation Initialisation Result (SSIP 2006) Snake July 7, 2006 5 / 16
Introduction Active Contour Models - Theory Implementation Results and Outlook Introduction • Snake is a form of Active Contour • Introduced by Kass, Witkin and Terzopoulous • Energy minimizing spline • Depending on Shape and Location of the Object • Used for Segmentation • Not sufficient to converge the contours to the image • Interaction process needed (SSIP 2006) Snake July 7, 2006 6 / 16
Introduction Active Contour Models - Theory Implementation Results and Outlook Overview 1 Introduction 2 Active Contour Models - Theory 3 Implementation 4 Results and Outlook (SSIP 2006) Snake July 7, 2006 7 / 16
Introduction Active Contour Models - Theory Implementation Results and Outlook Greedy Algorithm • The quantity is minimized by: � E = ( α ( s ) E cont + β ( s ) E curv + γ ( s ) E image ) ds • E cont and E curv : first and second order continuity constraints • E image : measures image quantity (edge strength or intensity) (SSIP 2006) Snake July 7, 2006 8 / 16
Introduction Active Contour Models - Theory Implementation Results and Outlook Overview 1 Introduction 2 Active Contour Models - Theory 3 Implementation 4 Results and Outlook (SSIP 2006) Snake July 7, 2006 9 / 16
Introduction Active Contour Models - Theory Implementation Results and Outlook Implementation Used Frameworks • Image Processing: Intel OpenCV library http://sourceforge.net/projects/opencvlibrary/ • GUI: Qt 4.1.4 http://www.trolltech.com/ • Source Code Documentation: Doxygen http://www.stack.nl/ dimitri/doxygen/ (SSIP 2006) Snake July 7, 2006 10 / 16
Introduction Active Contour Models - Theory Implementation Results and Outlook Demo (SSIP 2006) Snake July 7, 2006 11 / 16
Introduction Active Contour Models - Theory Implementation Results and Outlook Algorithm • Iterative Algorithm • Neighborhood of each point is examined at each iteration • Energy calculation for the neighborhood • New location is determined by the minimized energy point • Only closed contours are considered (SSIP 2006) Snake July 7, 2006 12 / 16
Introduction Active Contour Models - Theory Implementation Results and Outlook Overview 1 Introduction 2 Active Contour Models - Theory 3 Implementation 4 Results and Outlook (SSIP 2006) Snake July 7, 2006 13 / 16
Introduction Active Contour Models - Theory Implementation Results and Outlook Results (SSIP 2006) Snake July 7, 2006 14 / 16
Introduction Active Contour Models - Theory Implementation Results and Outlook Outlook • More constraints could be added to obtain better results • Preprocessing steps could be implemented • 3D Object Segmentation • Possibility to change parameters in the gui for different situations • Gradient Vector Flow (instead of Greedy Algorithm) • Switch from Snake to Balloons to cover concave structures Additional Information: • SSIP2006 - Project Homepage • http://snake.sourceforge.net/ (SSIP 2006) Snake July 7, 2006 15 / 16
Thank you very much for your attention! (SSIP 2006) Snake July 7, 2006 16 / 16
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