Fingerprint Features

Semantic Conformance

Terms / Definitions / Scope

Patrick Grother

March 5, 2010
INCITS 378 Conformance Clause

2 Conformance

A system conforms to this standard if it satisfies the mandatory 

requirements herein for extraction of minutiae from a fingerprint 

image as described in Section 5 and the generation of a minutiae 

data record as described in Section 6.

Extraction of minutiae = semantic conformance

Check by referencing original image

Generation of record = syntactic conformance

Check by parsing and validating
INCITS 378 on Placement

2004 :: 5.3.2 Minutia Placement on a Ridge Ending

The minutia for a ridge ending shall be defined as the point of forking of the medial 

skeleton of the valley area immediately in front of the ridge ending. If the valley area 

were thinned down to a single-pixel-wide skeleton, the point where the three legs 

intersect is the location of the minutia. In simpler terms, the point where the valley 

“Y”s, or (equivalently) where the three legs of the thinned valley area intersect.

The standards contain analogous text for bifurcations also.

2007 :: 5.3.2 Minutia Placement on a Ridge Ending

The minutia for a ridge ending shall be defined as the point of forking of the medial 

skeleton of the valley area immediately in front of the ridge ending. If the valley area 

were thinned down to a single-pixel-wide skeleton, the point where the three legs 

intersect is the location of the minutia. In simpler terms, the point where the valley 

“Y”’s, or (equivalently) where the three legs of the thinned valley area intersect. A 

Ridge Ending shall be encoded only if all of the legs used to calculate the minutiae 

angle length (as defined in 5.4.2 – Angle of a Ridge Ending) are greater than or equal 

to 0.02 inches in length.
Minutiae from two products

Insertion / Deletion

Angle Difference

Angle, position and type Differences
Native vs. Proprietary

False NonMatch Rate at 

False Match 

Rate of 0.01

Supplier of Template Matcher

Proprietary Native 

Standard

Supplier of 

Enrollment 

Template

NEC 0.0047 0.0129

Cogent 0.0089 0.0136

Sagem 0.0089 0.0140

PROPRIETARY

Representation of the template is completely unconstrained.

Construe it to be the supplier’s “best effort maximum accuracy” template.

NATIVE 

Representation of the template is constrained by the INCITS 378 standard

One supplier generates and matches the template. 
Performance Interoperability

False Non-Match 

Rate at False 

Match Rate of 0.01

Supplier of Verification 

Template + Template Matcher

NEC

Supplier of 

Enrollment 

Template

NEC 0.0129

Red values refer to NATIVE performance : One vendor generates and 

matches all templates.
Performance Interoperability

False Non-Match 

Rate at False 

Match Rate of 0.01

Supplier of Verification 

Template + Template Matcher

NEC Sagem

Supplier of 

Enrollment 

Template

NEC 0.0129 0.0205

Sagem 0.0316 0.0140

Red values refer to NATIVE performance : One vendor generates and 

matches all templates.
Performance Interoperability

False Non-Match 

Rate at False 

Match Rate of 0.01

Supplier of Verification 

Template + Template Matcher

NEC Sagem Cogent

Supplier of 

Enrollment 

Template

NEC 0.0129 0.0205 0.0300

Sagem 0.0316 0.0140 0.0207

Cogent 0.0417 0.0225 0.0136

Red values refer to NATIVE performance : One vendor generates both 

templates and matches them.
2D Minutiae Density

Intensity, I(x, y), is proportional to 

the estimated likelihood that a 

minutiae will be found by a 

template generator at (x,y).

No registration applied.

No consideration of angle, type, 

class, or quality value.

Each 2D density function is 

estimated from ~ 72000 

templates derived from 368x368 

images collected using a single 

model of sensor.

These effects are observed for 

other optical sensors.

Order of appearance is not the alphabetic order of vendors in the MINEX reports

Terminology

Michael Indovina IAD - Image Group 11

Rolled (ink capture) Flat (ink capture)

Latent Fingerprint

(powder “lift”) 

“Conventional” Fingerprints

Ten-print roll, Exemplar Flat, Exemplar Latent, Mark
Traditional + Proprietary EFS

Type 9 fields

» 5-12 Standard Format Features

» 13-30 IAFIS Features

» 31-55 Cogent Systems Features

» 56-70 Motorola Features

» 71-99 Sagem Morpho Features

» 100-125 NEC Features

» 126-150 M1-378 Features

» 151-175 Identix Features

» 300-399 Extended Friction Ridge 

Feature Set

Traditional: Fields 9.005-9.012

» Minutiae

» (x, y, theta, type, Q)

» Core

» Delta

» Ridge count

» Impression type

» Pattern class
Extended Feature Sets :: Aims

» A “brave new standard”

» Updates ANSI/NIST Type 9

» Enhanced handling of traditional features

» Larger “vocabulary” of features (e.g. “level 3”)

» Includes features already present in proprietary sets

» Intended to document everything seen by examiner

» Archival format: inter-examiner markup, legal evidence

» NIST intent:

» Quantitative support for draft standard (a la IREX, MINEX)

» Bring standards-based implementations to market

» Support iterative R&D
Extended Feature Set

» Location + orientation

» ROI, orient, finger + segment

» Ridge quality map

» Ridge flow map

» Ridge wavelength map

» Tonal reversal, lateral 

reversal

» Friction ridge quality metric

» Possible growth or 

shrinkage

» Cores, delta, core-delta 

ridge counts

» Distinctive Characteristics

» Minutiae

» Minutiae ridge counts + 

confidence

» Dots

» Incipient ridges

» Creases + linear 

discontinuities

» Pores

» Latent substrate

» Latent matrix

» No presence indicators

» Corresponding features