bicubic interpolating zoom

[Bart Coppens]

As I see you're using the "Numerical Recipes" book, I think it might be wise 
to check out their license at http://www.numerical-recipes.com/infotop.html , 
especially the second and third point in 'Information on redistributing 
Numerical Recipes'. While it's clear that at the moment you're just 
implementing the algorithm and not actually copying, redistributing and or 
directly modifying their code, it should be something to keep in mind while 
using the book. 
 
Bart Coppens