[ardiansyahputra]

I am very confused about hessian matrix of gaussian function.
I am making final project at mycollege. I use hessian matrix of gaussian function to detect vessel of retinal image. How to get value of inside matrix (ex:matrix 3x3)?
How to apply hessian matrix on image? what is eigenvalue?what for?
Could U please give me a programming language like visual basic or mathlab that describe about hessian matrix to track vessel?
I am veryglad to receive your reply.
thank you for your help.

[jwwicks]

Hello ardiansyahputra,

ardiansyahputra, on 25 Jul, 2008 - 11:31 PM, said:

I am very confused about hessian matrix of gaussian function.
I am making final project at mycollege. I use hessian matrix of gaussian function to detect vessel of retinal image. How to get value of inside matrix (ex:matrix 3x3)?
How to apply hessian matrix on image? what is eigenvalue?what for?
Could U please give me a programming language like visual basic or mathlab that describe about hessian matrix to track vessel?
I am veryglad to receive your reply.
thank you for your help.

Try the explaination on Wiki...
http://en.wikipedia..../Hessian_matrix

There's a link to an approximation algorithm as well...

Not sure what code you're using for matrix is this a roll your own or are you using valarray...

Try posting your code so we can see what you have so far and we might be able to help out a little more.

JW

[ardiansyahputra]

Here is example of matlab for describing hessian matrix to track vessel. But I can not know about threshold.

I = imread ('D:\program matlab\im0324.bmp');
I = im2double(I);
J = rgb2gray (I);

imwrite (J,'J.bmp');
[x y]=size(J)
h = fspecial('gaussian',[3 3], 0.55) %gaussian function
[px,py] = gradient(h, 0.2, 0.2) % derivative of gaussian
n = [px,py];
b = conv2 (J,n); %convolution
g = hess (h) % hessian matrix
z = eig (g) % eigenvalue (used to threshold)
hhj
K = medfilt2(; %median filter
d = ordfilt2(K,9,[1 1 1; 1 1 1; 1 1 1]) %dilasion
figure(1), imshow (J)
figure(2), imshow (
figure(3), imshow (K)
figure(4), imshow (d)


I dont know what I write above that's true.
I need yourexplanation.
But I had been suggested by scientiest Mr. Sofka
to read paper:
@InProceedings{frangi:miccai98,
author = {A. Frangi and W. J. Niessen and K. L. Vincken and
M. A. Viergever},
title = {Multiscale Vessel Enhancement Filtering},
booktitle = {Medical Image Computing and Computer Assisted Intervention
1998},
pages = {130--137}

But I am still confused.

Please, help me...
thx