Video surveillance systems capture images of casino players (including the targetted card counter, thief or fraudster). It then breaks the image up into code and runs a search to find a match and identify the player. Scarily enough, Google has started to develop a pretty sophisticated version for its Picasa photo service. And Facebook, of course, is pretty good at this sort of stuff and getting better.
Facial recognition, is of course, on of the key talents that we all have. Think about it- it´s pretty amazing how you can so quickly recognise a person through their looks alone- a skill that has taken us millions of years to develop. Computers have only recently been developing the same ability.
For a guide to how they actually work, let´s take Identix as an example- one of the big players in this market, who have developed facial recognition software called FaceIt. FaceIt, can pick a face out of a crowd, isolate the face from the rest of the background and compare it to a database of stored faces. The software measures various arrtibutes of the face to generate a match.