image processing - MATLAB - Trying to understand how the function maketform() works -

i encounter problem code, , me solve it, need understand how function maketform() works, , more specific 'custom' option.

as mentioned, used 'custom' option ask inverse_fcn (at least), , dont know how need define function?, should contain?, should like?

i appreciate if can give me real example or direct me one.

(in general, code .glt file (for mapping purposes), , need convert transformation - t)

thanks in advance, gal :)

i read (a lot) since asked question, , things became clear. wanted share insight on subject.

1. what x , it? - x spatial coordinates of image, meaning x contains 2 columns, compose grid of coordinates image. example, 3x3 images x like:

x(:,1)

ans =

 1  2  3  1  2  3  1  2  3 

x(:,2)

ans =

 1  1  1  2  2  2  3  3  3 

2. what t , it? t transformation create when call function 'maketform', , when use 'custom' option, transform function define 'maketform'. example:

invrse_fnc = @(x,~) dosomething(x);

t = maketform('custom', 2, 2, [],invrse_fnc, []);

from understand function should defined when using 'custom', can u want, notice, input 2 columns of spatial coordinates of image.

i hope understand subject, , comments welcome.

good night , programming all!