Setup for edge detection

[Guus]

Hello to all,

I just started to use vision and I had a question. If I use edge detection to determine the center of a cylinder at the bottom and at the top how can I use instruct edge detection to preform edge detection between the 2 centers?

Guus

[BruceAmmons]

Your question isn't very clear.  Can you post an image that will clarify your problem?  It sounds like maybe you want to use Find Circular Edge, but it is hard to tell.

Bruce

[Guus]

Sorry I wasn't that clear but I will try to clarify. I have 2 distinct edges A and B (in the .doc you can see the picture). Than I use edge detector and caliper to determine the center of 1 and 2, and the center of 3 and 4. If vision has determined the centers I want vision to do an edge detector between 5 and 6. This is done because I want to do an edge detection in the center of the rod but the rod is not always in the same place.

Guus

[BruceAmmons]

You did a pretty good job explaining it this time.  In fact, you pretty much described the solution as well.

You need to do the edge detection across 1-2 and 3-4.  Each edge detection should give you two points for the edges.  You can average the points (add together and divide by two) to get the midpoint.  Now you have two points to create a line for your third edge detection.

What part are you getting stuck on?  If there is one specific step that is unclear, I could give you more detailed instructions.

Bruce

[Guus]

What is unclear to me is how i can let vision draw a rio for edge detection from 5 to 6 if these point are given from caliper.

[ThSa]

Guus,
you cannot do this directly with the Vision Assistant. You could do it with the VBAI or with LabVIEW.
In the attachement you find a possible solution implemented with LV 8.20 (edge.vi and incl. one for lv 8.0 (subfolder))

You have to adapt the input parameters for the ROIs to your pictures as well.

BR,
ThSa

[Guus]

Well I still use the Evaluation version and it doesn't allow me to build a VI in labview. But is it possible to let caliper give the coordinates to edge detection so it automatically draws the line between them and looks if there are edges?

Guus

[ThSa]

It is possible in LV or with the VBAI but it is not possible with the Vision Assistant.

BR,
ThSa