International IEC ISO Standard IS0/IEC 29794-4 Information technology - Second edition 2024-09 Biometric sample quality Part 4: Finger image data Technologies de I'information - Qualité d'échantillon biométrique- Partie 4: Données d'image de doigt Reference number ISO/IEC 29794-4:2024(en) @ ISO/IEC 2024 IS0/IEC29794-4:2024(en) COPYRIGHT PROTECTED DOCUMENT IS0/IEC2024 be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below orIso'smemberbodyinthecountryoftherequester. ISO copyright office CP401·Ch.deBlandonnet8 CH-1214 Vernier, Geneva Phone: +41 22 749 01 11 Email: copyright@iso.org Website: www.iso.org Published in Switzerland @ IS0/IEC 2024 - All rights reserved i IS0/IEC 29794-4:2024(en) Contents Page Foreword. .iv Introduction. ..V Scope. 1 2 Normative references .1 3 1 Terms and definitions. 4 Abbreviated terms .2 5 Conformance .2 6 Finger image quality measures. .3 6.1 Overview.. 6.1.1 General .3 6.1.2 Methods for mapping to the desired value range 6.1.3 Constituent of local quality measures. .4 6.1.4 Constituentofglobalqualitymeasures .4 6.1.5 Image preprocessing. 2. .7 6.1.6 Image examples. 6.2 Normative contributive quality components .7 6.2.1 General .7 6.2.2 Orientation certainty level .7 6.2.3 Local clarity. .9 6.2.4 Frequency domain analysis (FDA) .14 6.2.5 Ridge valley uniformity 15 6.2.6 Orientation flow. .17 6.2.7 MU .19 6.2.8 MMB .19 6.2.9 Minutiae count in finger image. .19 6.2.10 Minutiae count in centre of mass region. 20 Minutiae quality based on local image mean 20 6.2.11 Minutiae quality based on local orientation certainty level .21 6.2.12 6.2.13 Region of interest image mean 22 Region of interest orientation map coherence sum 6.2.14 .24 Region of interest relative orientation map coherence sum 25 6.2.15 Quality feature vector composition 25 6.2.16( 6.3 Non-normative quality measures. 28 6.3.1 28 General 6.3.2 29 Radialpowerspectrum Gabor filter bank 30 6.3.3 Unified quality score .32 6.4 Methodology for combining quality components .32 6.4.1 6.4.2 Training method .32 Finger image quality block .33 7 7.1 Binary encoding. 33 7.2 XML encoding 33 7.3 Quality algorithm identifiers. 33 35 Annex A (normative) Conformance test assertions Annex B (informative) Factors influencing fingerprint image quality 57 Annex C (informative) Area consideration 59 Bibliography. 60 @ IS0/IEC 2024 - All rights reserved iii