How to find a circle segment coordinates in image?

Hi,

I need to count the number of hairs in a circle located in a image (the images are attached), but I don't want to relate to the rest of the image. How can I isolate the circle from the rest of the image?

Itai

Answer 1

[Image Analyst]

If you use a template that is opaque, say, black, then it would be trivial: just threshold.

[Itai Kadosh]

But I received this image and I can't change the way the image is taken. There is a way to mark only the circle?

Thanks, Itai

[Image Analyst]

You can use imellipse. See attached demo.