How can i extract features from sclera blood vessel structure using gabor filter.?

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Hello sir,
I want to extract features from the blood vessel structure of sclera. First sclera area is detected and then blood vessels are enhanced from the sclera portion, from that enhanced blood vessel features are to be extracted.
I am trying to do feature extraction by means of GABOR FILTER... can u please tell me sir which are feature that can be extracted by means of gabor filter ??? How can i apply gabor filter to this enhanced blood vessel structured image ??

Accepted Answer

Image Analyst
Image Analyst on 28 Nov 2013
There's nothing built in to MATLAB to do sclera vessel detection, so I think you should look at the published literature to find a suitable algorithm, then code it up in MATLAB. Start your search in section 20.5 here: Vision Bibliography. If you need help with MATLAB code (syntax, error messages, program flow, etc.) then come back and attach your images and m-files.
  6 Comments
Image Analyst
Image Analyst on 6 Feb 2017
Look for white parts. I'm sure the Vision Bibliography will have some papers for describing more robust algorithms in detail.
mak carlos
mak carlos on 7 Feb 2017
i can not find any relate from Vision Bibliography my problem is how to detect the sclera part can u help me ??

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More Answers (4)

ANJU
ANJU on 10 Mar 2015
I used frangi filter for enhancencement and a first level wavelet transform is also used... I didnt get the output using gabor filter
  1 Comment
kapil khond
kapil khond on 16 Mar 2015
@anju,i used frangi filter for sclera enhancement ,it worked thanks a lot,Now i will be doing feature extraction using Gray-Level Co-Occurrence Matrix (GLCM),as we know glcm gives the values of various features like contrast,correlation,energy ,homogeneity,entropy,cluster prominence,cluster shade and many more,please tell me from all these features which features are useful in "sclera based authentication ". also the output of frangi filter is attached please tell whether the output is appropriate or not.

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kapil khond
kapil khond on 17 Feb 2015
can you tell how to detect sclera area from an eye ,thanks in advance

kapil khond
kapil khond on 9 Mar 2015
Edited: Walter Roberson on 8 Jan 2016
@anju,i am doing sclera based authentication ,i got sclera area now i want to perform sclera blood vessel enhancement , i tried that using gabor filter but instead of enhancing vessels it is enhancing eye edges ,pleae tell me what changes i need to do in code or in parametrs of gabor filter ,if you have done using different method please provide its source code thanks in advance.
below is the code of gabor filter
theta=pi/2; lambda =3.5; gamma=0.3; sigma=2.8; psi=0;
sigma_x = sigma; sigma_y = sigma/gamma;
nstds = 5; xmax = max(abs(nstds*sigma_x*cos(theta)),abs(nstds*sigma_y*sin(theta)));
xmax = ceil(max(1,xmax));
ymax = max(abs(nstds*sigma_x*sin(theta)),abs(nstds*sigma_y*cos(theta)));
ymax = ceil(max(1,ymax));
xmin = -xmax;
ymin = -ymax;
[x,y] = meshgrid(xmin:xmax,ymin:ymax);
x_theta=x*cos(theta)+y*sin(theta);
y_theta=-x*sin(theta)+y*cos(theta);
gb= exp(-.5*(x_theta.^2/sigma_x^2+y_theta.^2/sigma_y^2)).*cos(2*pi/lambda*x_theta+psi);
%subplot(3,2,5); %imshow(gb); %title('theta=...'); %imagesc(gb); %colormap(gray); %title('theta=...');
image_double=im2double(K);
figure,subplot(2,2,1);
%imshow(image_double);
%figure(3);
filtered1 = conv2(image_double,gb);
%subplot(3,2,5); imshow(filtered1);
title('gabor filter when theta is pi/2');
%colormap(gray);
%title('theta=pi/2');

Mohammad Aloudat
Mohammad Aloudat on 28 Jun 2016
that is good for white sclera but what about red sclera. it share the same feature of skin.

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