[fprint] age and fingerprints

[Mark Vytlacil]

I have been experimenting with the microsoft reader for a while now and have 
been getting a lot of false rejections. Cleaning the reader and more care in 
pressing help, but not that much. The minutiae are not very consistant in 
position or number. I was puzzled that Daniel reported such good results.

Comparing my image to the sample image on the wiki shows that mine is 
much "muddier". I have gaps in the ridges, smeary areas, and various unclear 
spots. Many of these make for minutiae that are really artifacts rather than 
true ridge patterns. I considered that my reader was defective and captured a 
blurry image.

Then I got my son (age 22) to try it. His fingerprint is as clear as the 
sample on the wiki! I could clearly see all of the true minutiae on his 
print. I hate to think that I am getting old and my fingerprint is getting 
soft, but I guess so.

The windows software works well for me, but it captures the same finger 4 
times to enroll a print. We could do the same and just enroll the subset of 
minutiae that consistantly match. For verification, we would consider the 
proportion of enrolled minutiae that matched. It is easy to make suggestions 
like this, but not so easy to do the implementation work. Looking at the 
code, I can see that you would have to bring some match data out of the 
bozorth library routines or add some functionality to them to generate this 
subset and use it. As it is now, the main match function just returns a 
score.