Calculating bivariate polynomial coefficients in Matlab!

Hello all,

I have the following bivariate polynomial system:

Xa= ax1 + ax2*X + ax3*Y + ax4*X^2 + ax5*Y^2 + ax6*XY

and

Ya= ay1 + ay2*X + ay3*Y + ay4*X^2 + ay5*Y^2 + ay6*XY

This system acts as a distortion model in pixel coordinate to real world coordinate camera system. I know the pixel coordinates and the actual distances of the calibration pattern from the camera and I need to extract the coefficients (ax1 ... ax6) (ay1 ... ay6) of the bivariate polynomial system using least squares. Since I have not find any ready made function for bivariate polynomial fitting, could you please have any ideas on how to do that?

Thank you in advance!

Answer 1

[John D'Errico]

download polyfitn from the file exchange.