Contents
% Copyright (c) 2020 % Authors: % F. Pierre, M. Amendola, C. Bigeard, T. Ruel % and P.-F. Villard % % This program is free software: you can redistribute it and/or % modify it under the terms of the GNU Affero General Public % License as published by the Free Software Foundation, either % version 3 of the License, or (at your option) any later % version. % % This program is distributed in the hope that it will be % useful, but WITHOUT ANY WARRANTY; without even the implied % warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR % PURPOSE. See the GNU Affero General Public License for more % details. % % You should have received a copy of the GNU Affero General % Public License along with this program. If not, % see <http://www.gnu.org/licenses/>.
EvolutionSnake2D
Compute the evolution of a Snake Model.
Syntax.
V = EvolutionSnake2D(image, V_init); V = EvolutionSnake2D(image, V_init, ...);
Description.
V = EvolutionSnake2D(image, V_init); returns a polygon provided by the snake evolution model on the image initialized with V_init.
Example.
Loading path.
if exist('OCTAVE_VERSION', 'builtin') pkg load image; end addpath('functions') % Image choice. image='shamrock.png'; % Reading of initial image and transformation into gray values. I_init = double(rgb2gray(imread(image))); % Subdivision parameter of initial contour. k=3; % Drawing and subdivision of the initial polygon. V_init = subdivision( selectPoints(I_init), k ); % Snake computation V_final= EvolutionSnake2D(I_init, V_init, ... 'Alpha', 2500, ... 'Beta', 1000, ... 'Sigma', 1, ... 'Gamma', 0.0005, ... 'BalloonCoefficient', -100, ... 'BalloonSmoothing', 70, ... 'MaxIteration', 1500, ... 'CubicSplineRefinement', 'on', ... 'Verbose', 'off'); % Display. figure, displayImageAndSnake(I_init,V_final); title('Snake Segmentation')
Left click to select a position Right click to stop

Input arguments.
- Alpha is the
parameter.
- Beta is the
parameter.
- Gamma is the time step.
- BalloonCoefficient is the ballon coeficient.
- BalloonSmoothing is the standard deviation of the smoothing kernel of the balloon force.
- MaxIteration is the maximum number of iterations.
- Verbose enable the display, can be 'on' or 'off' (default).
- CubicSplineRefinement enable the refinement of the snake discretization.
- Sigma is the Gaussian blur dispersion parameter.