ANSI/NIST-ITL 1-2011 - NIST Visual Image Processing Group ...

ANSI/NIST-ITL 1-2011Data Format for the Interchange of Biometric and Forensic InformationFigure 22:EFS Examples of areas and points of correspondence in rolledexemplar, latent, and plain exemplar images13.9.59 EFS Field 9.360 Area of Correspondence / AOCThis field is to be used only when two or more images contained in a singleANSI/NIST file are compared as candidates for individualization (potentialmates). The area of correspondence 46 is a polygon enclosing the region ofusable ridge detail present in both images being compared. If the correspondingareas are discontinuous, more than one area of correspondence may be definedfor a pair of images.One Type-9 record may have multiple AOCs defined that correspond to differentimages, as shown in Figure 23. For example, a latent could have areas ofcorrespondence with both the rolled and plain exemplars from one subject, or alatent could have areas of correspondence with candidate exemplars from twodifferent subjects.This field consists of 3 information items:• The first information item (IDC Reference) indicates the target image for agiven AOC. 47Brad Wing 6/23/10 1:09 PMComment: Reorganized for clarity ofpresentation•46 Comparison features are especially appropriate in transactions in which one latent image is bundled with oneor more candidate/potential match images in order to show which areas and points in the latent image correspond toareas and points in the candidate images. Such transactions may be useful for exchanges between examiners, or forcommunicating results back from AFIS searches. See Figure 22 for an example. Note that the latent has two differentareas of correspondence, one for each of the exemplars.47Figure 23 shows examples of the use of IDC references in Corresponding Regions of Interest. The first image (IDC 01)has a single AOC, corresponding to the second image, so IDCref=02; the second image (IDC 02) has AOCscorresponding to each of the other images, with IDCref=01 and IDCref=03; the third image (IDC 03) has a single AOC,corresponding to the second image, so IDCref=02.118DRAFT 2