digitally process latent fingerprint

[freeasinfreedom]

Hi,

I'm trying to test the security of a computer based fingerprint sensor
against fake fingers. The fingerprint samples are on an overhead
slide. Do you have any ideas about how can I copy them to be able to
process them on a computer?

I've tried:
a) taking photos
b) scanning them

but nothing works well...

Regards,
Athanasios.