transforming image co-ordinates

[sammy346]

I am using a standard USB webcam to capture an image.  I wish to calibrate the image using the same features on a standard computer monitor - trapezoid and parellelogram etc. to resize the image to account for the angle of the camera with respect to the object being viewed.

The captured image will also contain several objects that will be detected by other image processing routines.

Where would I find information about an algorithm to convert between the pixel co-ordinate system from the raw image to the actual real world coordinate system.

Basically I need to find an algorithm for trapezoid and parallelogram etc.

[McCarty]

Hello sammy346,

You can find more information on spatial calibration on page 3-7 of the NI Vision Concepts Manual.  If you search for the word calibration in the NI Vision for LabVIEW Help, you can find more information on spatial calibration and the NI Vision VI tools (such as IMAQ Learn Calibration Template.vi) that are at your disposal.  I suggest you look over the Perspective Calibration Example.vi and Nonlinear Calibration Example.vi examples that you can find in the NI Example Finder by searching for the word calibration.

Best Regards,
T. McCarty