How to extract feature in an image?

I have a segmented image now i have to extract feature from the image. Which will be the best approach to take? Please help

This is the segmented image

[Asif Hasan]

I have already used gabor filter (gaborfilterbank & gaborfeature which i downloaded from fileExchange) but when i input this image it gives me feature but mostly focused on edge rather than sclera part. How do i solve this problem? I am attaching those images

This is the magnetize gabor filter

This is the real gabor filter

Please help.

[chukka Ranjith]

can u send me the code... not totally i just need the logic... just send 3 lines of gabor filter in matlab

Answer 1

[Image Analyst]

Why are you using Gabor filter? What do you want to measure, and how do you think Gabor will do that?

See my Image Segmentation Tutorial: http://www.mathworks.com/matlabcentral/fileexchange/25157-image-segmentation-tutorial---blobsdemo--

[Asif Hasan]

Thanks for reply sir. i want to extract the sclera blood vessel feature for recognition purpose. i did some study and they use gabor filter for feature extraction of sclera.

[Image Analyst]

You said Gabor "gives me feature but mostly focused on edge rather than sclera part." So now we know you don' t want edges or texture info like Gabor helps with, so what do you want? What EXACTLY do you want from the sclera part? The area of it? It's average brightness or color? What?

[Asif Hasan]

Sir, for human identification i need to extract the blood vessel structure so that i can match with original image.like the image i need only the blood vessel line.

[Image Analyst]

Are you following the recipe int he paper? Also, the iris can be used for identification also so maybe for more robustness you should analyze both the iris and the sclera.

[Asif Hasan]

Sir , i am only working on sclera recognition and i am following a paper named "A NEW APPROACH FOR HUMAN IDENTIFICATION USING THE EYE by N. Luke Thomas " and he used gabor filter for Vein Enhancement and line descriptor to extract the vein structure in the presence of noise and deformation.Now i want to use the method but i can't find it correct. so please help...

[Image Analyst]

Sorry, but I don't have the time to donate to your project. If it's something simple we can help but can't really put in the time required to translate a scientific article into MATLAB code - that cannot be done in 5 minutes or so, it would take way more time.

[Asif Hasan]

Sir, after using gabor filter i get a matrix of 19200*1 of type double with min 0 and max 0.0389. How do i show it in a 2D plot or in a image? @ImageAnalist

[Image Analyst]

Why is it 1-D? Maybe you can use plot(). Or maybe use reshape to put it back into a rectangular image and use

imshow(image2D, []);  % Must use [] if looking at a double class image.

[Asif Hasan]

Gabor filter returns 1D matrix. Is it possible i can threshold this matrix because in matrix there are 0 or more than 0? If possible how can i apply adaptive thresholding or other? @ImageAnalyst

[Image Analyst]

I don't really know. I don't use Gabor things. Sure, you can threshold globally or adaptively/locally - whatever makes sense to you.