There's a fair amount of F/OSS software from JPL available to do this sort of calibration. It's used to calibrate cameras used on Mars rovers, among other things. The target pattern for calibration is a bunch of big circular dots on a background.
On 11/23/08 7:56 PM, "Bruce Griffiths" <[EMAIL PROTECTED]> wrote: Tom Van Baak wrote: >> I need to determine the position of a instrument with a 1mm accuracy or less. >> The instrument is not connected to a mechanical device but is separate & >> independent. >> The surface which the instrument is positioned on is close to the size of a >> 11"x11" square. >> > > 1 mm or better accuracy on a 300x300 mm surface can be > obtained with a cheap webcam mounted above the surface > and a little bit a creative software. > > /tvb > Dont forget to calibrate the camera distortion and ensure that this doesnt over over time. i.e. lock the focus and ensure the camera position, tilt etc with respect to the reference surface do not vary. Bruce _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.