acknowledgements for ansi/nist-itl 1-2011 - NIST Visual Image ...

ANSI/NIST-ITL 1-2011 - UPDATE 2013 DRAFT VERSIONcenter of the gap in the ridge.• A discontinuity is a point where the ridge stops briefly and restarts again withoutshifting. A wider gap in the ridge flow, or where the ridges do not line up across thedivide, should be marked as two ridge endings, not a discontinuity. A series ofdiscontinuities in a line (such as a cut or crack) should be marked as a lineardiscontinuity, using the Field 9.342: EFS creases and linear discontinuities /CLD. A discontinuity is marked at the center of the gap in the ridge.This field consists of three information items. The first two ('x' coordinate/ CLX and 'y'coordinate ' CLY) are the coordinates of one endpoint in units of 10 micrometers (0.01 mm).The third information item is the type / CLT of feature. It is:P (Protrusion), I (Indentation), or D (Discontinuity).F.6.6Corresponding featuresThese fields are used to define the areas or points that correspond or do not correspond betweentwo or more of the images contained in the current transaction: when images are compared ascandidates for individualization (potential mates), the corresponding areas and points can beretained in these fields; similarly, the reasons for complex exclusions can be indicated. Points ofCorrespondence may be marked using any type of feature, and are explicitly not limited tominutiae.Comparison features are especially appropriate in transactions in which one latent image isbundled with one or more candidate/potential match images in order to show which areas andpoints in the latent image correspond to areas and points in the candidate images. Suchtransactions may be useful for exchanges between examiners, or for communicating resultsback from AFIS searches. See Figure 12: EFS areas and points of correspondence in rolledexemplar, latent, and plain exemplar images for an example. The latent illustrated has twodifferent areas of correspondence, one for each of the exemplars.F.6.7.1 Field 9.361: EFS corresponding points or features / CPF instructionsThis field, described in Section 8.9.7.48 , is used to label points or features for comparison ofthe current feature set with other Type-9 feature sets in this transaction, as illustrated in Figure10: EFS locations of major flexion creases.This field is to be used only when two or moreimages contained in a single transaction are compared, either as candidates for individualization(potential mates), or for annotating reasons for exclusion. For each of the images beingcompared, specific points or features are marked in each of the type-9 records, withcorrespondence indicated by the use of the same label. Labels within a single Type-9 recordshall be unique.May, 2013 DRAFT VERSION UPDATE 2013 Page 499