Accuracy

[n 516]

I'm using IMAQ PCI-1408 and RS140 Camera with a vi program to do an edge detection. A few IMAQ functions are used in that vi such as IMAQ Create, Snap, Image mask, IMAQ Set Simple Calibration, IMAQ Convert Pixel to Real World, IMAQ Rake...... I need to know how to estimate the accuracy of the measurement. Where can I find that information?

[nestor-sg]

A straight rule of thumb would be to divide the real-world length of your X axis field of view by the number of pixels your image has in the same axis of view. For example, 60mm lenght in X axis of an image that has 640 pixels resolution... 60/640 = 0.09375 mm/pixel. The same will apply on the Y axis calculation.

However, if you are doing calibration you can use the 'IMAQ Get Calibration Info VI', check the error map, the instructions on how to interpret it is on page 3-13 of the IMAQ Vision Concepts Manual. That will give you a clue of what accuracy you might be missing. The Concepts Manual can also be found on the Start >> Programs >> National Instruments >> Vision >> Documentation directory.

Good luck!

Nes
tor.