Detect holes in filled circle

[Alvaro.S]

Hi to all, first of all thanks a lot for reading this post and being able to help.

I would like to detect holes in a filled circle. See example:

What is the best tool/way to detect this?

I have tried to detect them with "pattern matching" but the results are not reliable.

Any ideas?

Thanks a lot

[wiebe@CARYA]

It depends...

What exactly do you want? What do you want to detect? The number of "broken" pixels? Coordinates of the holes? Or the number of holes?

Can you already successfully detect the circles? If so, detecting the holes can be done by labeling all objects, and then checking the coordinates. Or by masking out everything but the circles.

[Alvaro.S]

Hi,

Thanks a lot for replying.

I would like to detect the number of holes and its area.

Right now I detect the big circle, not the holes inside of it.

[wiebe@CARYA]

So use that circle as a (inverse) mask. Then do an object detection to detect the small holes.

[Alvaro.S]

Thanks for replying,

What tool have I to use for object detection that you say? ¿pattern matching?

thanks again.

[wiebe@CARYA · Accepted solution]

I don't have access to an IMAQ installation right now, but I'd say something like the Particle Analysis Example is doing.