I have a problem of interpolating a 2D motion field. What I know is that the

motion field will be smooth (NO discontinuity) and I have some holes in it

which I need to fill. My data size is rather large: several thousands data

points and several thousand places to be interpolated as well. At the moment

I am trying to treat the horizontal and vertical component as two separate

2D surfaces and interpolate them separately using radial basis functions.

The trouble is: evaluating the coefficients for the RBFs from first

principles (i.e. inverting big matrices) is too time and memory consuming.

Does anyone out there know of a iterative method to solve the problem? I

would like an algorithm which is not too mathematical to understand.

Any help will be appreciated.