INTERNATIONAL ISO/IEC STANDARD 29794-4 First edition 2017-09 Information technology Biometric sample quality - Part 4: Finger image data Technologies de I'information - Qualité d'echantillon biométrique - Partie 4: Données d'image de doigt Reference number ISO/IEC 29794-4:2017(E) EC @IS0/IEC2017 ACKEY, MA thout license from IHS IS0/IEC 29794-4:2017(E) COPYRIGHT PROTECTED DOCUMENT IS0/IEC 2017, Published in Switzerland All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form written permission. Permission can be requested from either ISO at the address below or ISO's member body in the country of the requester. ISO copyright office Ch. de Blandonnet 8 . CP 401 CH-1214 Vernier, Geneva, Switzerland Tel. +41 22 749 01 11 Fax +41 22 749 09 47 [email protected] www.iso.org @ IS0/IEC 2017 - All rights reserved Jniv/5926867100,User=JACKEY,MA or networking pemited without license from IHS IS0/IEC 29794-4:2017(E) Contents Page Foreword ..iv Introduction. ..V 1 Scope. ..1 2 Normative references 3 Terms, definitions, symbols and abbreviated terms. 4 Conformance ..2 5 Finger image quality metrics .2 5.1 Overview .2 5.1.1 General. .2 5.1.2 Constituent of local quality metrics 3 5.1.3 Constituent of global quality metrics .3 5.1.4 Image preprocessing 3 5.1.5 Image examples. 5 5.2 Normative contributive quality metrics 5 5.2.1 General .5 5.2.2 Orientation certainty level .5 5.2.3 Local clarity score 7 5.2.4 Frequency domain analysis (FDA) score. 11 5.2.5 Ridge valiey uniformity .13 5.2.6 Orientation flow. ..14 5.2.7 MU .15 5.2.8 MMB. ..15 5.2.9 Minutiae count in finger image 16 5.2.10 Minutiae count in center of mass region. .16 5.2.11 Minutiae quality based on local image mean ..16 5.2.12 Minutiae quality based on local orientation certainty level .17 5.2.13 Region of interest image mean. .17 5.2.14 Region of interest orientation map coherence sum 19 5.2.15 Region of interest relative orientation map coherence sum 20 5.2.16 Quality feature vector composition. 20 5.3 Non-normative quality metrics 23 5.3.1 General. 23 5.3.2 Radial power spectrum 23 5.3.3 Gabor quality score.. 25 5.4 Unified quality score. 27 5.4.1 Methodology for combining quality metrics .27 5.4.2 Training method. .27 6 Finger image quality data record. ..28 6.1 Binary encoding. .28 6.2 XML encoding. .29 6.3 Quality algorithm identifiers. ..30 Annex A (normative) Conformance test assertions ..32 Annex B (informative) Factors influencing fingerprint image character ..44 Annex C (informative) Area consideration .46 Bibliography .47 yrtnematonalAll rights reerved ii ACKEY,MA Not for Resale,