zett - 9:12 am on Apr 6, 2012 (gmt 0)
The burden of proof isn't on the infringing party to prove anything... the burden is on the legitimate copyright holder to show they own the rights.
...which is the whole point of holding back originals. You can easily prove that you are the creator of the work in question. Letting an expert compare the original to the copy (that the infringer has been using) will then PROVE that it is an infringement. The only way out for the infringer is by proving that he was rightfully using the image, e.g. by presenting a valid licence of some sort, or by showing that he is the original creator. He won't be able to, and will lose the case.