%?This?Matlab?file?demomstrates?a?variational?level?set?method?that?improves?the?original?method?in?Li?et?al‘s?paper
%????“Level?Set?Evolution?Without?Re-initialization:?A?New?Variational?Formulation“
%????in?Proceedings?of?CVPR‘05?vol.?1?pp.?430-436.
%?Author:?Chunming?Li?all?rights?reserved.
%?E-mail:?li_chunming@hotmail.com
%?URL:??http://www.engr.uconn.edu/~cmli/

clear?all;
close?all;
Img?=?imread（‘Head.bmp‘）;??%?The?same?cell?image?in?the?paper?is?used?here
Img=double（Img（::1））;
sigma=1.5;????%?scale?parameter?in?Gaussian?kernel?for?smoothing.
G=fspecial（‘gaussian‘15sigma）;
Img_smooth=conv2（ImgG‘same‘）;??%?smooth?image?by?Gaussiin?convolution
[IxIy]=gradient（Img_smooth）;
f=Ix.^2+Iy.^2;
g=1./（1+f）;??%?edge?indicator?function.

epsilon=1.5;?%?the?papramater?in?the?definition?of?smoothed?Dirac?function

timestep=5;??%?time?step
mu=0.04;??%?coefficient?of?the?internal?（penalizing）?energy?term?P（\phi）
??????????%?Note:?The?product?timestep*mu?must?be?less?than?0.25?for?stable?evolution

lambda=5;?%?coefficient?of?the?weighted?length?term?Lg（\phi）
alf=1.5;???%?coefficient?of?the?weighted?area?term?Ag（\phi）;
???????????%?Note:?Choose?a?positive（negative）?alf?if?the?initial?contour?is?outside（inside）?the?object.


%?define?initial?level?set?function?（LSF）?as?-c0?c0?at?points?outside?and?inside?of?a?region?R?respectively.
[nrow?ncol]=size（Img）;??
c0=2;????%?The?constant?value?used?to?define?binary?level?set?function?as?initial?LSF;
?????????%?Using?larger?value?of?c0?usually?slow?down?the?evolution.
?????????
initialLSF=c0*ones（nrowncol）;
w=8;
initialLSF（w+1:end-w?w+1:end-w）=-c0;??

u=initialLSF;
figure;imagesc（Img?[0?255]）;colormap（gray）;hold?on;
[ch]?=?contour（u[0?0]‘r‘）;??????????????????????????
title（‘Initial?contour‘）;

%?start?level?set?evolution
for?n=1:1000
????u=EVOLUTION_LSD（u?g?lambda?mu?alf?epsilon?timestep?1）;??????
????if?mod（n20）==0
????????pause（0.001）;
????????imagesc（Img?[0?255]）;colormap（gray）;hold?on;
????????[ch]?=?contour（u[0?0]‘r‘）;?
????????iterNum=[num2str（n）?‘?iterations‘];????????
????????title（iterNum）;
????????hold?off;
????end
end
imagesc（Img?[0?255]）;colormap（gray）;hold?on;
[ch]?=?contour（u[0?0]‘r‘）;?
totalIterNum=[num2str（n）?‘?iterations‘];??
title（[‘Final?contour?‘?totalIterNum]）;

figure;
mesh（u）;
title（‘Final?level?set?function‘）;

?屬性????????????大小?????日期????時間???名稱
-----------?---------??----------?-----??----
?????目錄???????????0??2013-12-29?20:12??Variational_LevelSet\
?????目錄???????????0??2013-12-29?16:03??Variational_LevelSet\_LevelSet\
?????文件???????64193??2013-12-28?10:55??Variational_LevelSet\_LevelSet\Added_Circut1.bmp
?????文件???????68613??2013-12-28?10:56??Variational_LevelSet\_LevelSet\Added_Circut2.bmp
?????文件???????83018??2013-12-28?10:55??Variational_LevelSet\_LevelSet\Added_Circut3.bmp
?????文件???????86161??2013-12-28?10:55??Variational_LevelSet\_LevelSet\Added_Circut4.bmp
?????文件???????83586??2013-12-28?10:54??Variational_LevelSet\_LevelSet\Added_Circut5.bmp
?????文件???????38029??2013-12-28?10:55??Variational_LevelSet\_LevelSet\Added_Circut6.bmp
?????文件????????2407??2013-12-28?11:54??Variational_LevelSet\_LevelSet\Demo1.m
?????文件????????2638??2013-12-28?11:56??Variational_LevelSet\_LevelSet\Demo1_ManualBinaryInitial.m
?????文件????????2380??2013-12-28?11:55??Variational_LevelSet\_LevelSet\Demo2.m
?????文件????????2608??2007-03-20?14:33??Variational_LevelSet\_LevelSet\Demo2_ManualBinaryInitial.m
?????文件????????3425??2013-12-28?11:58??Variational_LevelSet\_LevelSet\Demo3_initialFromThresh.m
?????文件????????1125??2007-01-17?22:51??Variational_LevelSet\_LevelSet\EVOLUTION_LSD.m
?????文件???????65818??2013-12-28?10:48??Variational_LevelSet\_LevelSet\Head.bmp
?????文件??????801246??2006-02-03?16:17??Variational_LevelSet\_LevelSet\levelset_CVPR05.pdf
?????文件???????24576??2007-01-31?22:49??Variational_LevelSet\_LevelSet\LSD.dll
?????文件???????10078??2007-02-01?01:41??Variational_LevelSet\_LevelSet\noisyStar_SNR_20_to_10.bmp
?????文件???????16434??2004-07-23?19:36??Variational_LevelSet\_LevelSet\twocells.bmp
?????文件????????8134??2004-07-05?18:59??Variational_LevelSet\_LevelSet\twoObj.bmp