[Insight-users] arbitrary warp filter

[Rahul Chander]

Hello itk developers,
I need to implement an arbitrary transform which is non-linear in 
nature.  
The transform acting on physical co-ordinates (x0,y0) produces 
(x1,y1) and can look something like this for 2D:
[x1;y1]'=[g(x0,y0);h(x0,y0)]',  where g, h are arbitrary functions.

e.g.
[x1;y1] = [ax^2+by^3+c; d xy+ e y^2+f]  

for x=x0, y=y1
and constants a,b,c,d,e,f.

I was thinking of starting off with a simple 2D transform's .txx and 
.h files to implement my own transform according to the above 
function.  At this point I do not know where in the itk code the 
transform matrix gets multiplied with a point's co-ordinates to 
result in the new set of co-ordinates.

ie.  [x1;y1]' = [some function of (x,y)] * [x0;y0]'   <--- where in 
itk does this multiplication operation occur?

Secondly, which transform's code would be the easiest to modify for 
my needs. And last of all, is there a way around all this without 
going into low level implementation?

Thanks in advance.
Rahul.

-- 
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Rahul Chander
IV Year Electrical Eng.
The University of British Columbia
Linux User:207994
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