The overview is:
- Many fingerprint scanners use undocumented proprietary communications and can only be accessed through the DLL supplied with the scanner. This can be a problem on Raspberry as the DLLs are often MS Windows only
- A lot of fingerprint scanners calculate minutae on the device and are only able to return those, without being able to return the fingerprint images.
- There is a linux library that is able to talk to a number of different fingerprint scanners. that library concentrates on getting back minutae rather than on getting back fingerprint images, so examining the code for any one device will give you varying degrees of information about what you might need to do in order to return images for the device. Some of the devices might be quite capable of returning images, but when you look at the code and all you see is that you have to send it (for example) 0xE7 0xEB 0x32 0x99 to get it to return a minutae, then that doesn't give you much clue as to what sequence of bytes you would need to get back an image.
- Some devices are pretty easy to communicate with, and well documented too.
At this time there is no point going into any kind of detail; at this point the question is much like "Can you control a vehicle using Raspberry Pi"... It's a "Ummm, maybe??" kind of question.
