detect eye iris in a binary image

Question

I am developing an eye tracker application in emgu CV, To track eyes i need to detect iris accurately ,So i used hough circles , but in some cases it fails because the shape of iris is not a perfect circle, So i decided to convert eye image in to binary and detect iris ,

To convert it to binary i used

grayframeright_1 = grayframeright_1.ThresholdBinary(new Gray(threshold_value), new Gray(220));

and the result is

enter image description here

Now how can i detect iris in the above binary image ?Can i run blob detector to detect iris ?

Please help me to figure this out, your help will be highly appreciated , I am running out of time for my deadline.

Providing code sample would be useful

Thanks in advance

Actually, it doesn't have to do with any programming language despite the fact maybe he's coding it in C#. — pid
I have tried blob detection but it is detecting whole image as blob... I am implementing this application in emgu CV. — gouthaman93

pid pid · Accepted Answer · 2014-02-03T22:51:31

You can try erosion. I've used it in a image processing class at university to find the visual center of airplanes in the sky and it worked surprisingly well.

Erosion is a fairly simple operator used in broader practice like blob detection, which you already mentioned.

Erode should remove border pixels of irregular shapes, leaving at last, just a moment before the shape completely vanishes, only few pixels. The geometrical center of those pixels is c, the visual center of the irregular shape. Starting from c draw a circle of radius r which is completely inscribed in the irregular shape. The circle at c with radius r is an approximation of the iris. Or at least so the story goes.

When I say erosion I mean this: example of erosion

This was just my personal idea based on university work, I've never done this in the industry.

Maybe you should look at a more serious approach to the problem which does not use erosion but wavelets: Iris recognition

I'm very curious. If you try this could you please share your results/findings? A quick comment would suffice!

detect eye iris in a binary image

1 Answers