function?[maskprobabilities]?=?random_walker（imgseedslabelsbeta）?
%Function?[maskprobabilities]?=?random_walker（imgseedslabelsbeta）?uses?the??
%random?walker?segmentation?algorithm?to?produce?a?segmentation?given?a?2D??
%image?input?seeds?and?seed?labels.?
%?
%Inputs:?img?-?The?image?to?be?segmented?
%????????seeds?-?The?input?seed?locations?（given?as?image?indices?i.e.??
%???????????as?produced?by?sub2ind）?
%????????labels?-?Integer?object?labels?for?each?seed.??The?labels??
%???????????vector?should?be?the?same?size?as?the?seeds?vector.?
%????????beta?-?Optional?weighting?parameter?（Default?beta?=?90）?
%?
%Output:?mask?-?A?labeling?of?each?pixel?with?values?1-K?indicating?the?
%???????????object?membership?of?each?pixel?
%????????probabilities?-?Pixel?（ij）?belongs?to?label?‘k‘?with?probability?
%???????????equal?to?probabilities（ijk）?
%?
%?
%10/31/05?-?Leo?Grady?
%based?on?the?paper:?
%Leo?Grady?and?Gareth?Funka-Lea?“Multi-Label?Image?Segmentation?for?
%???Medical?Applications?based?on?Graph-Theoretic?Electrical?Potentials“??
%???in?Proceedings?of?the?8th?ECCV04?Workshop?on?Computer?Vision?Approaches??
%???to?Medical?Image?Analysis?and?Mathematical?Methods?in?Biomedical?Image??
%???Analysis?p.?230-245?May?15th?2004?Prague?Czech?Republic??
%???Springer-Verlag?
%Available?at:?http://cns.bu.edu/~lgrady/grady2004multilabel.pdf?
%?
%Note:?Requires?installation?of?the?Graph?Analysis?Toolbox?available?at:?
%http://eslab.bu.edu/software/graphanalysis/?
?
%Read?inputs?
if?nargin?????beta?=?90;?
end?
?
%Find?image?size?
img=im2double（img）;?
[X?Y?Z]=size（img）;?
?
%Error?catches?
exitFlag=0;?
if（（Z~=1）?&&?（Z~=3））?%Check?number?of?image?channels?
????disp（‘ERROR:?Image?must?have?one?（grayscale）?or?three?（color）?channels.‘）?
????exitFlag=1;?
end??
if（sum（isnan（img（:）））?||?sum（isinf（img（:））））?%Check?for?NaN/Inf?image?values?
????disp（‘ERROR:?Image?contains?NaN?or?Inf?values?-?Do?not?know?how?to?handle.‘）?
????exitFlag=1;?
end?
%Check?seed?locations?argument?
if（sum（seeds<1）?||?sum（seeds>size（img1）*size（img2））?||?（sum（isnan（seeds））））??
????disp（‘ERROR:?All?seed?locations?must?be?within?image.‘）?
????disp（‘The?location?is?the?index?of?the?seed?as?if?the?image?is?a?matrix.‘）?
????disp（‘i.e.?1?<=?seeds?<=?size（img1）*size（img2）‘）?
????exitFlag=1;?
end?
if（sum（diff（sort（seeds））==0））?%Check?for?duplicate?seeds?
????disp（‘ERROR:?Duplicate?seeds?detected.‘）?
????disp（‘Include?only?one?entry?per?seed?in?the?“seeds“?and?“l(fā)abels“?inputs.‘）?
????exitFlag=1;?
end?
TolInt=0.01*sqrt（eps）;?
if（length（labels）?-?sum（abs（labels-round（labels））?????disp（‘ERROR:?Labels?must?be?integer?valued.‘）;?
????exitFlag=1;?
end?
if（length（beta）~=1）?%Check?beta?argument?
????disp（‘ERROR:?The?“beta“?argument?should?contain?only?one?value.‘）;?
????exitFlag=1;?
end?
if（exitFlag）?
????disp（‘Exiting...‘）?
????[maskprobabilities]=deal（[]）;?
????return?

?屬性????????????大小?????日期????時(shí)間???名稱
-----------?---------??----------?-----??----

?????文件???????4192??2013-04-02?00:07??random?walker\random_walker.m

?????文件???????1495??2013-04-02?00:08??random?walker\random_walk_example.m

?????目錄??????????0??2013-04-02?10:08??random?walker

-----------?---------??----------?-----??----

?????????????????5687????????????????????3