Juan C. Santaella enlightened me by writing:
Hi!!
I wonder if any of you has worked with the DigitalPersona Platinum
SDK. I have to start a C# application that integrates the u.are.u
4000B fingerprint reader using the SDK. Any help or information about
it is welcome. Thanks in advance.
JC
I have not used it with .net yet, but I integrated with the platinum
version sdk using Delphi last year. I obviously can't say how it would
be used in .net (since I haven't done it yet, most likey using interop
for COM unless they have a .net native assembly now), but the Delphi
integration through their COM object was pretty straight forward.
Two things that I will say:
1. Their SDK's are a bit pricey, but the support during integration is
excellent.
2. I had a bit of trouble intitially wrapping my head around the
methodogy behind biometrics. I integrated the system with a POS
application and used the readers to gain entry into the system. What I
didn't realize is that you can say "here's a coptured template, find me
the record that matches it in my database". Instead, it was about a
percentage of match. Because of this, you have to compare the scanned
template against "possible" matches and determine if you think it's a
match based on the "score" that you get back.
What I ended up doing was creating a "pool" of finger prints in memory
on each pos station. So now, when an employee scanned their
fingerprint, I would first loop through the pool of finger print
templates in memory first (since it was much faster than db access).
If a match is found in memory, that was all I had to do since I store
the employee ID with the template pool in memory. If there was no
match found, then I would have to do a sequential scan of "active"
employee records in the database to find the match. Once a match was
found, the template was placed in the memory pool.
This particular application does not have many employees on at once so
it was ok to store in workstation memory. If it was a lot of possible
matches or many employees, I would have just used a table in the
database to store "active" finger print templates.
Either way, the memory pool of fingprint templates is always cleared
once a day.
The result of all this was that it took about 1-3 seconds to match a
template against the database the first time around. Once the template
was placed in memory pool of a workstation (as needed, "Lazy loading"?)
login through biometrics was measured in 10ths of a second. Very fast.
HIH
--
Warm Regards,
Lee
"Upon further investigation it appears that your software is missing
just one thing. It definitely needs more cow bell..."
