How to detect circles in the given image?

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Anannya Uberoi
Anannya Uberoi on 17 May 2017
Commented: pawarcse on 24 May 2017
I am working on a series of images- some blurry, some sharp. My aim is to detect the outer boundary of the iris.
After adaptive thresholding, the image becomes:
I have applied similar adaptive thresholding to all my test images- some of them are blurry, some have sharp focus measures. A few of my results:
I want to extract the circular boundary which marks the iris through a common code. Although it is quite visible intuitively, neither of regionprops or imfindcircles is able to locate the iris. Moreover, in some cases, it is not exactly a complete circle, and gets trimmed across the left and right edges while capturing the photo.
Any help or advice on this would be much appreciated!
  1 Comment
Swarooph
Swarooph on 17 May 2017
More pre-processing could help. Try performing some morphological operations to reduce the noise (non-circular features) in the image before using imfindcircles. Some documentation to help: http://www.mathworks.com/help/images/morphological-filtering.html

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Answers (1)

Image Analyst
Image Analyst on 17 May 2017
There are so many iris detection algorithms. Just check the literature for the latest and greatest one(s): http://www.visionbib.com/bibliography/contentspeople.html#Face%20Recognition,%20Detection,%20Tracking,%20Gesture%20Recognition,%20Fingerprints,%20Biometrics
21.5.3 Biometrics, Iris Recognition Systems
21.5.3.1 Iris Based Biometrics, Biometrics Engineering Research Center, Dongguk University
21.5.3.2 Iris Recognition Systems, Infrared, Near-Infrared, NIR Based
21.5.3.3 Iris Recognition Systems, Wavelet Based
21.5.3.4 Iris Detection, Segmentation and Localization Systems
21.5.3.5 Iris Recognition Systems, Systems, Evaluation, Comparison, Surveys
  3 Comments
Image Analyst
Image Analyst on 18 May 2017
I don't really know, short of delving into it myself. Perhaps you need to adjust some parameters with it.
pawarcse
pawarcse on 24 May 2017
Hello, I am currently working on Iris Recognition and I am having problem in detection of pupil and sclera Boundary. Please help me to solve this problem!! I am using Daugaman Algorithm.

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