INTERNATIONAL ISO/IEC STANDARD 39794-2 First edition 2023-09 Information technology Extensible biometric data interchange formats - Part 2: Finger minutiae data Reference number IEC ISO/IEC 39794-2:2023(E) ISO @IS0/IEC2023 IS0/IEC 39794-2:2023(E) COPYRIGHT PROTECTED DOCUMENT @IS0/IEC2023 All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may the internet or an intranet, withoutpriorwrittenpermission.Permission can be requested from eitherIso at the addressbelow orIso's memberbody inthe country oftherequester ISO copyright office CP 401 · Ch. de Blandonnet 8 CH-1214Vernier,Geneva Phone: +41 22 749 01 11 Email: [email protected] Website: www.iso.org PublishedinSwitzerland i @ IS0/IEC 2023 - All rights reserved IS0/IEC 39794-2:2023(E) Contents Page Foreword .V Introduction. .vi 1 Scope. 1 2 Normative references ..1 3 Terms and definitions. 1 4 Symbols and abbreviated terms 4 5 Conformance .4 6 Modality-specific information .5 6.1 Purpose. 5 6.2 Minutia description .5 6.3 Minutia kind 5 6.3.1 General .5 6.3.2 Unique minutia 5 6.3.3 Encoding trifurcations 5 6.4 Minutia location. 6 6.4.1 General .6 6.4.2 Coordinate system .6 6.4.3 Minutia location of a ridge ending (encoded as valley skeleton bifurcation point), 6 6.4.4 Minutia location of a ridge bifurcation .7 6.4.5 Minutia location of a ridge ending (encoded as ridge skeleton endpoint) .8 6.4.6 Usage of the minutia placement. .9 6.5 Minutiae direction... 9 6.5.1 Angleconventions. 9 6.5.2 Minutiadirectionofaridgeending(encodedasvalleyskeletonbifurcation point), .9 6.5.3 Minutia direction of a ridge bifurcation .9 6.5.4 Minutia direction of a ridge ending (encoded as ridge skeleton endpoint) .9 6.6 Core and delta placement. 9 7 Abstract data elements. 11 7.1 Purpose. 11 7.2 Finger minutiae data. 12 7.3 Version. 12 7.4 Representation block 12 7.5 Position. 12 7.6 Impression 12 7.7 Minutiae data .13 7.8 Spatial sampling rate 14 7.9 Ridge end encoding 14 7.10 Capture date and time 14 7.11 Capture device 14 7.11.1 Capture device model identifier 14 7.11.2 Certification identifier blocks. 14 7.11.3 Certification schemes for finger images 14 7.11.4 Capture device technology identifier. 15 7.12 Biometric sample quality blocks 16 7.13 Generic ridge counts. 16 7.14 Fourneighbourridge counts 17 7.15 Eight neighbour ridge counts 17 7.16 Core data .18 7.17 Deltadata 18 7.18 Zonal quality 18 @ IS0/IEC 2023 - All rights reserved ii IS0/IEC 39794-2:2023(E) 7.19 PAD data block .19 7.20 Vendor specific data. .19 8 Encoding 19 8.1 Tagged binary encoding .19 8.2 XML encoding .19 8.3 On-card biometric comparison format .19 8.3.1 Overview .19 8.3.2 Minutia placement 21 8.3.3 Encoding 21 8.3.4 Minutia position 21 8.3.5 Minutia type .21 8.3.6 Minutia angle 21 8.3.7 Number of minutiae and truncation. 22 8.3.8 Usage of extended data for the on-card comparison format ..22 8.3.9 Biometric comparison parameters .31 9 Registered format type identifiers ..34 Annex A (normative) Formal specifications ..35 Annex B (normative) Conformance test methodology .46 Annex C (informative) Encoding examples. .51 Annex D (informative) Detailed description of finger minutiae location, direction, type .54 Bibliography. .79 iv @ IS0/IEC 2023 - All rights reserved IS0/IEC39794-2:2023(E) Foreword ISO (the International Organization for Standardization) and IEC (the International Electrotechnical Commission) form the specialized system for worldwide standardization. National bodies that are members of ISO or IEC participate in the development of International Standards through technical committees established by the respective organization to deal with particular fields of technical activity. IsO and IEC technical committees collaborate in fields of mutual interest. Other international organizations, governmental and non-governmental, in liaison with ISO and IEC, also take part in the work. The procedures used to develop this document and those intended