Reference coordinate system in Labview

[BeKo]

Hallo,

I have the following problem: I want to set a reference coordinate system to my image.
First of all, I detect a mark on my image to specifie the new coordinate system.
After that, I want to do a kind of tracking. In a while loop I get images where I try to detect a circle with the IMAQ find circular edge.
I need the center point of the circle. This works fine but the center point is not relate to the new coordinate system, but to the left upper corner.
I post my VI. Labview Version 8.2 with Development Module 8.2

[JoBa]

Hello Beko,

please take a look at the VI "Simple Calibration Example" which should have been installed by NI Vision and can be found using the NI Example finder.

In there, "IMAQ Convert Pixel to Real World" is used to compute the coordinates relative to the configured origin. You might also have to add a simple Grid Descriptor to the "IMAQ Set Simple Calibration" VI, just like in the example.

Regards,
Johannes

NI Germany 650124