RBF or Thin-Plate Splines Image Warping

Radial basis function/Thin-plate spline function and demo for 2D image warping.

Radial basis function/Thin-plate spline 2D image warping.
[imo,mask] = rbfwarp2d( im, ps, pd, method)
input:
im: image 2d matrix
ps: 2d source landmark [n*2]
pd: 2d destin landmark [n*2]
method:
'gau',r - for Gaussian function ko = exp(-|pi-pj|/r.^2);
'thin' - for Thin plate function ko = (|pi-pj|^2) * log(|pi-pj|^2)
output:
imo : output matrix
mask : mask for output matrix, 0/1 means out/in the border

Bookstein, F. L.
"Principal Warps: Thin Plate Splines and the Decomposition of Deformations."
IEEE Trans. Pattern Anal. Mach. Intell. 11, 567-585, 1989.
Inspired by
https://cn.mathworks.com/matlabcentral/fileexchange/24315-warping-using-thin-plate-splines
Code by WangLin
2015-11-5
wanglin193_hotmail.com