function?[Lambda1Lambda2IxIy]=eig2image（DxxDxyDyy）
%求hessian矩陣的特征值Lambda1和Lambda2并給出邊緣方向
%?This?function?eig2image?calculates?the?eigen?values?from?the
%?hessian?matrix?sorted?by?abs?value.?And?gives?the?direction
%?of?the?ridge?（eigenvector?smallest?eigenvalue）?.
%?
%?[Lambda1Lambda2IxIy]=eig2image（DxxDxyDyy）
%?Lambda1較小值
%

%
%?|?Dxx??Dxy?|
%?|??????????|
%?|?Dxy??Dyy?|


%?Compute?the?eigenvectors?of?J?v1?and?v2
Dxx=double（Dxx）;%sqrt使用double類型
Dxy=double（Dxy）;
Dyy=double（Dyy）;
tmp?=?sqrt（double（（Dxx?-?Dyy）.^2?+?4*Dxy.^2））;
v2x?=?2*Dxy;?v2y?=?Dyy?-?Dxx?+?tmp;

%?Normalize
mag?=?sqrt（v2x.^2?+?v2y.^2）;?i?=?（mag?~=?0）;
v2x（i）?=?v2x（i）./mag（i）;
v2y（i）?=?v2y（i）./mag（i）;

%?The?eigenvectors?are?orthogonal
v1x?=?-v2y;?
v1y?=?v2x;

%?Compute?the?eigenvalues
mu1?=?0.5*（Dxx?+?Dyy?+?tmp）;
mu2?=?0.5*（Dxx?+?Dyy?-?tmp）;

%?Sort?eigen?values?by?absolute?value?abs（Lambda1）check=abs（mu1）>abs（mu2）;
Lambda1=mu1;?Lambda1（check）=mu2（check）;
Lambda2=mu2;?Lambda2（check）=mu1（check）;

Ix=v1x;?Ix（check）=v2x（check）;
Iy=v1y;?Iy（check）=v2y（check）;

?屬性????????????大小?????日期????時間???名稱
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?????文件??????36215??2011-04-14?16:06??frangifilter\aa.jpg

?????文件???????1159??2011-03-28?21:16??frangifilter\eig2image.m

?????文件???????4986??2011-04-28?16:16??frangifilter\FrangiFilter2D.m

?????文件???????1616??2011-04-01?14:13??frangifilter\gausstest.m

?????文件???????1026??2011-04-01?11:25??frangifilter\Hessian2D.m

?????文件??????22500??2009-09-30?15:33??frangifilter\imgaussian.c

?????文件???????2073??2009-09-24?14:09??frangifilter\imgaussian.m

?????文件???????1335??2010-03-02?05:09??frangifilter\license.txt

?????文件?????163322??2011-02-28?11:10??frangifilter\multiscale?vessel?enhancement?filtering.pdf

?????目錄??????????0??2011-04-28?16:15??frangifilter

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???????????????234232????????????????????10