circular edge

[declercq_tom@waak.be]

Hi all,

I use vision Builder AI 2012 and I'm having problems finding the right circular edge.

The edge I want found is not always the strongest one. Normally this isn't a problem (as I search for the first edge), but sometimes my program finds edges that I dont want to see. I've allready played with all of the parameters, but the results arent always as I would expect.

Is there any way to specify the coördinates of the center of the circular edge? This would really solve my problem, but I cannot find a parameter that does this.

With kind regards,

Tom

[KateB]

VBAI have a set coordinate step that you could use to identify ROI related to the coordinate, but you need other steps to build reference points for coordinate. For example, detected objects and matched pattern.

[Brad]

You should check out a shipping example that uses coordinate systems. Here's one that deal with circlular regions of interest that use a coordinate system:

<Vision Builder AI path>\examples\Detect Objects Example.vbai

Hope this helps,

Brad

[declercq_tom@waak.be]

Hi Kate and Brad,

Thanks for the reply.

I am using a coördinate system, but unfortunately I need to find the right circular edge first. This is really my first step.

My application needs to establish wich diameter the part is. This forms the basis for later tests. (If I find diameter 50 I go to state 50, if I find diameter 40 I go to ...).

I know the coördinates of where the centre of the circle should be found. So I was wondering if there was a possibility to include a statement somewhere (if x-centre - x-input > 10pixels or y-centre-y-input > 10 pixels = no circular edge)

with kind regards,

Tom

[ThiCop]

Hello Tom,

Can you share the part of your code that is currently handling this as well as a working example picture and a non-working one?

I'm quite interested in seeing where it exactly goes wrong.

Thanks in advance!

[Brad · Accepted solution]

You could try using the Detect Objects step which makes it easy to threshold the image to find objects (i.e. your circles), and then it has some advanced filtering options to discard unwanted objects (only keep objects with a circular shape..this is called the Heyward Circularity Factor and the closer to 1 it is the more circular it is, or filter objects that are too small too big or touching your Region of Interest. This step can even return the diameter of the object. This step is used in that example I showed you to count the holes in the oil filter, but you could use it for getting the circle position.

Hope this helps,

Brad

[declercq_tom@waak.be]

Hello Thierry,

I tried attaching my porgram, but for some reason I'm not able to. (The contents of the attachment doesn't match its file type)

Is there another way to attach vbai-programs?

For the moment I cant provide pictures. But hopefully tomorrow I'll be able to take and post some.

Brad,

I'll look into it and let you know if I can do something with the example.

Thanks for the response!

Tom

[ThiCop]

Hello Tom,

Brad his steps are for sure going to lead you on the right path.

My questions were more out of personal curiosity and to test it myself. 😉

If there would remain some issues, then we will find a (different) way to share the files.

Did you try to upload a vbai-file or did you change the extensions?

Have you tried compressing the files to an accepted forum-format?