Having trouble detecting iris/pupil of person with dark skin color.

asked 2013-08-02 01:18:19 -0500

MattiasR gravatar image

updated 2013-08-02 01:25:45 -0500

I am having trouble finding the pupil/iris of a person with dark skin color. It seems like a simple threshold does not work for this. Me and my friend, even though the pupil seem to have about the same dark color (gray scale) for the pupil, the thresholding value, for an accurate pupil detection, is 30 for dark guy, 100 for me.

Ive been playing around with infra red light, and it is possible to make the skin a bit less dark, but there is still no accurate way of detecting the pupil.

This is image with infra red: image description

After some gaussian: image description

One can se a darker spot in the image. But I cant get the houghcircles to return any circles on that image. And I still don't know if this will work (accurately enough) during streamin video. This is just One image that I work on, trying to find good parameters to detect the pupil.

Anyone that knows how to accurate detect pupil that has about the same color as the skin?

Edit: The image is not only infra red. I've removed the IR-blocking finter, and use IR leds to illuminate. But at this moment I dont use any visible-light-blocking-filter. But I will use it when I have one. Thanks!

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