回复： Re: 回复： Re: How to calculate how round the circle is?

[yangyang-rexxar]

Hi All

I have an enhanced picture as attached file, I would like to check if the holes are round, so a user define limit should be work out here.

Dose someone has experienced how to define how round the cirle is? Or I can say firstly if it is a round? Then decide how round it is. Could someone give concept interpret to me.

Im using Vision Builder and Vision Development Module, It's pleasure to see some samples from you.

Thanks so much.

帖子被paulbin在04-29-2008 03:38 AM时编辑过了

[MikeS81]

Hi paulbin,

i think you can use the "IMAQ Find Circluar Edge" vi.

Hope it helps.

Mike

[Andrey_Dmitriev]

Hi, Paulbin,

I guess, Heywood circularity factor may be helpful for you. This will give you closer to 1 for "round" particles.

Do it in the following way: Threshold->remove small particles->(optional postprocessing in binary space)->Particle analysis:

Test script in attachment.

best regards,

Andrey.

[yangyang-rexxar]

Hi Andrey

I can't find "Particle Analysis" in Assistant. My IDE is Vision Builder3.0/3.5.

[Andrey_Dmitriev]

Hi, paulbin,

I don't know if particle analysis included into Vision Builder 3.0/3.5.

Anyway you have Vision Development Module, and particle analysis should be here. Just go to Analysis palette in LabVIEW:

If you will need this in Vision Builder (Vision Builder AI assumed), then you have to create custom step with particle analysis

best regards,

Andrey.

[yangyang-rexxar]

Hi Andrey.

I followed your advice on my pictures. you can see my image source in attached pictures what is not taken in a very good ambient:), I tried to threshold >> Equalize >>Get Kernel(Laplacian) >> Convolute >> (Optional Particle filter) >> Particle Analysis(Heywood Circularity Factor), I get the result picture what is also attached, I found that the result factor is not represent how round the circular is? The ellipse and round ones have close factors. Could you tell me what is "Heywood Circularity Factor".

[yangyang-rexxar]

Ok, I will continue this thread, the original picture is attached, I would like to check if there is shadow in the circular area. Previously I would like to check how round it is, but regardless it is Find Circular Edge or Heywood Circularity Factor, there is no perfect results what can represent how round it is.

Now I would like to try to find if there is shadow area in circle, could someone advise?