How to create Arc ROI?

[danrom]

I need a ROI which if defined by an arc, is there a simple way to do this? I can create an arc overlay via the "IMAQ Overlay Arc", but can this be converted to a ROI?

 

 

any suggestions greatly appriciated...

[muks]

ok question time.

What is 1dimension?

 what is 2dimension?

What is the definition of arc?

If the arc you say is a "segment" of a circle then you can create an roi. An roi is a 2d thing and just an arc is a 1d thing right?To put it in other words you can overlay a line can you create a line roi. You can only create a rectangle roi. Please define the "arc". Please also expalin your application

[danrom]

Thank you for the fast response, I will try to explain my problem better..

I need to track a moving ball running along a path, and the arc (circle segment - bended line) should act as the ROI for edgedetection tool. Problem is illustrated in attached picture "ball path". 

I have tried to use the "IMAQ Convert Annulus to ROI" - but with this unwanted points gets detected (because the annulus crosses the path two times).. 

Any way to define this arc ROI? 

- Thanks

[BenParrott · Accepted solution]

Unfortunately, there is not an arc ROI. But you are on the right track using an annulus. First, create an annulus with the inner radius equal to the outer radius. Then use "IMAQ Convert Annulus to ROI" to create the ROI. Then pass this ROI to "IMAQ Concentric Rake 3". This should search for edges along a single arc.

Hope this is helpful

Ben

[danrom]

I believe this is the solution, thank you Ben

[muks]

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Then pass this ROI to "IMAQ Concentric Rake 3". This should search for edges along a single arc.

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You can vary the edge strength for better output