Migration from 500ppi to 1,000ppi Fingerprint Search Database

While the decision to go to 1,000 ppi on fingerprint card capture was made some time ago it would appear that the bad economy has slowed, if not completely halted the migration. Most states have not migrated to 1,000 ppi. fingerprint card capture, so there are only a few states that find themselves in a situation where they are running automated fingerprint identification systems with search files consisting of both 500 ppi and 1,000 ppi fingerprint card images. The FBI does plan to move to 1,000 ppi fingerprint cards at some point in the future, but I would expect, that they are unable to make the move until all the large states have migrated to the 1,000 ppi fingerprint card capture systems. The issues confronting states from migrating will be cost issue's:

• Bandwidth for the higher resolution fingerprint card images.
• Conversion costs.
• Fingerprint livescan units are twice as expensive for the higher resolution units.
• System maintenance costs are a % of system cost so there is significant increase.

The problem for the larger states, is that they are dependent on the smaller agencies who submit fingerprint cards via livescan. Many smaller agencies will not be able to shoulder additional livescan and bandwidth costs.

The FBI currently will accept the 1,000 ppi fingerprint images but they are storing the high resolution fingerprint images; they downsize the fingerprint image for searching and updating to the FBI fingerprint search database. So in effect the states submitting 1,000 ppi. fingerprint images are actually getting a 500 ppi. fingerprint search. This I would suspect was originally planned as a temporary solution by the FBI until all states moved to the higher resolution fingerprint systems.
So lets discuss some of the concerns with the migration from 500 to the 1,000 ppi fingerprint system. While getting a higher resolution fingerprint image should give agencies a more accurate fingerprint search is a logical assumption, the question is with the interim solution migrating to the higher resolution system will this assumption be true ? Running a system with fingerprint search database of 500ppi. and 1,000ppi. fingerprint images will create challenges for the fingerprint coders and matchers. The images are not the same size and they each are compressed using different compression algorithms with different ratios of compression. Will the interim fingerprint search system be able to match the current fingerprint system accuracy? The interim system would capture new fingerprint images at 1K ppi. and if an identification is made, replace the lower resolution fingerprint image with the new higher resolution fingerprint image. It is possible some states could manually convert all the hardcopy fingerprint cards in their database, reducing the number of lower resolution fingerprint cards left in the database as well as reducing the length of time they run the dual system. Remember so many fingerprint cards have been captured electronically over the last few years and these fingerprint images captured at 500 ppi cannot be interpolated up to 1,000 ppi. A big question is will the minutiae extraction algorithms and matcher algorithms be affected by having a mixed resolution database ? Each vendor,each agency, each version of afis software may be impacted a little or a lot. Remember the fingerprint minutiae extraction programs were developed for 500 ppi images and not for a dual resolution fingerprint systems. This is a question that has not been answered. I have not heard of any fingerprint system accuracy tests involving fingerprint systems with dual resolution fingerprint databases. I would also point out that most vendors test in a controlled situation with good quality fingerprint images to get the high fingerprint accuracy rates. In the real world the fingerprint accuracy rates are significantly lower because of poorly taken tenprints and partial latent images. In my experience the hit rate for latent fingerprint searches is seldom above 15%, this percentage is based on the number of unknown latent fingerprints entered into the system that are identified. Every examiner knows that getting a latent fingerprint hit is more dependent on the quality of the tenprint fingerprint image in the database than anything else. So whether the fingerprint card is captured at 500 ppi. or at 1K ppi the fingerprint accuracy, will be dependent on the quality of the fingerprint images captured at the livescan unit and how the matchers and coders handle dual fingerprint resolutions.