%?This?Matlab?program?demomstrates?the?level?set?algorithm?in?paper:
%????“Active?contours?driven?by?local?image?fitting?energy“?
%????to?appear?in?Pattern?Recognition?2010
%?Author:?Kaihua?Zhang?Huihui?Song?and?Lei?Zhang
%?E-mail:?zhkhua@mail.ustc.edu.cn?cslzhang@comp.polyu.edu.hk??
%?http://www4.comp.polyu.edu.hk/~cslzhang/

%??Notes:
%???1.?Some?parameters?may?need?to?be?modified?for?different?types?of?images.?Please?contact?the?author?if?any?problem?regarding?the?choice?of?parameters.
%???2.?Intial?contour?should?be?set?properly.

%?Date:?5/11/2009

clear?all;close?all;clc;

Img?=?imread（‘3c.bmp‘）;
Img?=?double（Img（::1））;
sigma?=3;%?the?key?parameter?which?needs?to?be?tuned?properly.
sigma_phi?=?0.5;%?the?variance?of?regularized?Gaussian?kernel
K?=?fspecial（‘gaussian‘2*round（2*sigma）+1sigma）;
K_phi?=?fspecial（‘gaussian‘5sigma_phi）;

[nrowncol]?=?size（Img）;

phi?=?ones（nrowncol）;
phi（15:nrow-1515:ncol-15）?=?-1;
figure;??imagesc（Img[0?255]）;colormap（gray）;hold?on;
contour（phi[0?0]‘b‘）;

timestep?=?1;
epsilon?=?1.5;
for?n?=?1:600???
??????[phif1f2Hphi]=?LIF_2D（ImgphitimestepepsilonK）;
??????phi?=?conv2（phiK_phi‘same‘）;
??????if?mod（n40）==0
??????pause（0.0001）;
??????imagesc（Img[0?255]）;colormap（gray）
??????hold?on;contour（phi[0?0]‘b‘）;
??????iterNum=[num2str（n）?‘?iterations‘];????????
??????title（iterNum）;????????
??????hold?off;
??????end
end

figure;
mesh（phi）;

?屬性????????????大小?????日期????時間???名稱
-----------?---------??----------?-----??----
?????文件???????17160??2007-10-07?22:31??3c.bmp
?????文件????????1460??2009-11-05?14:00??Demo.m
?????文件?????????894??2009-11-03?09:14??LIF_2D.m