The forward equation is not easily achieved, but I would think there will not be such extreme distortions as in perspective and arc. If there are, then one would just have to live with point or better bilinear interpolation. However, my main issue is how one goes about figuring out what the a,b,c,d constants should be!!!!
Yes, that's part of the problem. Again, PTlens can help with the solution:
First of all you can read these values for a lot of cameras from its database via Clens. Secondly, http://epaperpress.com/ptlens/calTargets.html gives hints on suitable targets, though it does not tell us the calibration algorithm itself, as this work is always performed by Tom Niemann himself. I think that is the trick he really sells with PTlens.
I though don't believe this task to be too tricky. It's probably straightforward: you have to determin the four polynominal coefficients from a suitable image. This means that you need the real coordinates of just two points in the image.
And I forgot: GIMP is also Open Source, so one might look at its code as well: http://www.gimp.org/downloads/
Greetings from Germany Wolfgang Hugemann _______________________________________________ Magick-users mailing list [email protected] http://studio.imagemagick.org/mailman/listinfo/magick-users
