What kind of colour matching algorithm are you using?

( mediocre HONKA HONKA, Thu 27 Mar 2008, 13:22, archived)

Using Photoshop
then the channel mixer and doing it by eye. a bit rushed as you can see. oh and I did a little blending on the edges so it looked a little less crappy
(semi pro : explorer, Thu 27 Mar 2008, 13:25, archived)