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

ANSI/NIST-ITL 1-2011 - UPDATE 2013 DRAFT VERSION8.9.7.18 Field 9.322: EFS core delta ridge counts / CDRThis field contains the count of intervening ridges between each core and delta. Eachridge count has a minimum and maximum value, so that a range may be noted. If theexact value is known, then that value should be put in the minimum and maximum fields.If only a minimum is known, such as when a delta is not visible, the maximum valueshall be omitted. Ridge counts may be any non-negative integer. When this field is usedfor fingerprints, ridge counts shall be provided between each core and each delta, unlessthere are more than two cores or two deltas in an accidental whorl, in which case only theleftmost and rightmost of the cores and deltas need be used for ridge counts. Eachsubfield represents a distinct core-delta ridge count. Each subfield consists of fourinformation items:• The first information item (core index / CIX) is the (1-based) index of thecore corresponding to this count (“1” if only one core is defined). If therelevant core is not defined, this shall be set to “U” to indicate an uppercore or “L” to indicate a lower core (whorls only), permitting minimumridge counts when cores are not in the region of interest.• The second information item (delta index / DIX) is the (1-based) index ofthe delta corresponding to this count (“1” if only one delta is defined). Ifthe relevant delta is not defined, this shall be set to “L” to indicate a leftdelta or “R” to indicate a right delta, permitting minimum ridge countswhen deltas are not in the region of interest.• The third information item (minimum ridge count / MNRC) contains theprecise ridge count, if it is known; otherwise, it contains the minimum ofthe range of ridge count values.• The fourth information item (maximum ridge count / MXRC) containsthe precise ridge count (if the count is known precisely), or the maximumof the range of ridge count values (if there is a known or estimatedmaximum); otherwise, it shall be omitted.8.9.7.19 Field 9.323: EFS center point of reference / CPRThis field contains the location of a center point of reference of a fingerprint, which maybe used to define how centered a fingerprint is, as a feature, for registration or orientation,and for quality measurements. While the core may serve some of the same purposes, acenter point of reference is defined for arches and provides a single center location forcomplex whorls, unlike cores. For more information about this field see ANNEX FF.6.3.2 Field 9.323: EFS center point of reference / CPR instructions.The center point of reference is the sole EFS feature that can be located outside of theEFS region of interest. For example, this allows the estimated center of the finger to bemarked even for an extreme side. The origin of CPR, like all other EFS features, is160