camera calibration user defined points

[muks]

Apart from the simple and grid calibration we have prepective calibration on which we need to give user defined points.Can some one tell me how many points need to be specified and how should it be given?

[DjDaveNI]

Hello muks,

The NI-VISION Concepts Manual (p 3-8 & 3-9) goes into detail about the calibration process. When I perform a calibration using user-defined points, I always go with 4 points. That’s because the Calibration Setup calls for at least 4 points, and there is not necessarily any advantage to use more.

 A complete walkthrough of how to perform the calibration with user-defined points can be found in the NI Vision Assistant help file by searching “user-defined points” and selecting the first result.

I hope this helps you out! 🙂

[muks]

Thanx david but when i choose 4 points it is not accepting that.Something to do with defining real world co-ordinates?

[DjDaveNI]

Hello muks,

What did you define your real-world coordinates as for each of the points? It’s possible that you may have specified your coordinate system backwards as well. Definitely check over these settings. The walkthrough in the help file (mentioned above) covers each step, and can help you diagnose the problem. Good luck! 🙂

[muks]

thanx david will check it and let you know if i am still stuck