Counting Black pixels in Matlab

[whu_Esle]

Hi everyone,

I need some help with counting the number of black pixels there are in the circle encompassing the pupil.

Can someone please help me?

Thank you very much!

 

[emresel]

Hi;
Apply a threshold to test each pixel (ie 10/255). If pixel value is smaller than threshold, increase counter.
But in this way probably you can count also some black pixels around the eyelash (any other black random or single pixels).
So you can do some testings using neighbor pixels.
ie if pixel next, above and below to tested pixel, is also below the defined threshold then accept it as black.
I hope you got my point.
Good luck.