The f2 Tattoo Module is designed to match an unknown tattoo against a database of tattoos in order to identify its owner. It will also match a partial shot of a tattoo, e.g. where it’s partially concealed by clothing, against the full tattoos in the database. Results are displayed as thumbnails of potentially matching tattoos, in descending order of Match%. Any of these can be selected to display the face and name of the owner. Tattoo recognition is similar to biometrics like fingerprints, face, and iris recognition in the way the image is encoded and then matched. However it differs in that a tattoo can be of anything, and be of any shape and size in the image. f2 determines the unique characteristics of each, e.g. lines, curves, colors, etc, and their relative positioning. This means that the matchlist can contain tattoos which appear totally different to the probe image. This happens because the characteristics being searched for by f2 will often be present in other images that visually look quite different to the probe. However the correct match (assuming it’s in the database) should almost always be at or near the top of the list. f2 Tattoo is designed to work with images captured under controlled conditions and that meet NIST Tattoo Capture Guidelines.

The result of a Tattoo search will be a number of thumbnail images that have the same or similar characteristics to the image being searched (the “probe” image), above a user-defined threshold. An officer can then visually scan the images to determine which, if any, is the same tattoo. The face associated with any selected tattoo is displayed, together with a link back to the original record. The benefit of f2 is therefore that it can find a matching tattoo in seconds where an officer could take many hours or longer to find a match.

Features:

• Matches complete tattoos and also those partially obscured
• Can also match scars and marks subject to sufficient detail
• Accesses images in existing external databases in read-only mode. It doesn’t store images itself unless set up to do so
• Links a matched image back to its associated face and details in the original database
• Text (if included in the original record) can be used to help filter out non-relevant matches
• Automatic enrollment of all images in a database. No limit to database size
• Import and automatic enrollment of images in a folder
• Automatic detection and enrollment of new images added to an external database
• Probe and database images can match at up to 45° rotational difference
• Searches any database of enrolled tattoos on a VPN under appropriate controls
• Side-by-side comparison of “probe” image and potential match for visual inspection, including magnification
• Straightforward to install and use f2 Tattoo is an independent but fully integrated module within the f2 Image Recognition Suite.

In this example, the partial probe image is on the right and top matches are displayed on the left. f2 finds the single correct match in the 5700-tattoo database. The non-match below it is visually different to the probe but rates highly because it includes leaves of similar shape.