Article: This standard was updated in 2011 and there are now more than 8 in the series. The body needs expert review and possible revision against the revised standard.
ISO/IEC 19794 Information technology—Biometric data interchange formats—Part 5: Face image data, or ISO/IEC 19794-5 for short, is the fifth of 8 parts of the ISO/IEC standard ISO/IEC 19794, published in 2005, which describes interchange formats for several types of biometric data. ISO/IEC 19794-5 defines specifically a standard scheme for codifying data describing human faces within a CBEFF-compliant data structure, for use in facial recognition systems. Modern biometric passport photos should comply with this standard. Many organizations and have already started enforcing its directives, and several software applications have been created to automatically test compliance to the specifications.
The standard is intended to allow computer analysis of face images for automated face identification and authentication, as well as human identification of distinctive facial features and human verification of computer identification results.
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Source: Information technology — Biometric data interchange formats —Part 5: Face image dataTechnologies de l’information — Formats d’échange de données biométriques —Partie 5: Données d’image de la faceINTERNATIONAL STANDARDISO/IEC19794-5Reference numberISO/IEC 19794-5:2005(E)First edition2005-06-15© ISO/IEC 2005Corrected version2016-09-01This is a preview - click here to buy the full publication
ii © ISO/IEC 2005 – All rights reservedCOPYRIGHT PROTECTED DOCUMENT© ISO/IEC 2005, Published in SwitzerlandAll rights reserved. Unless otherwise specified, no part of this publication may 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 or ISO’s member body in the country of the requester.ISO copyright officeCh. de Blandonnet 8 CP 401CH-1214 Vernier, Geneva, SwitzerlandTel. +41 22 749 01 11Fax +41 22 749 09 47copyright@iso.orgwww.iso.orgISO/IEC 19794-5:2005(E)This is a preview - click here to buy the full publication
ISO/IEC 19794-5:2005(E) © ISO/IEC 2005 — All rights reserved iii Contents Page Foreword .................................................................................................................................................................. viii Introduction ................................................................................................................................................................ ix 1 Scope .............................................................................................................................................................. 1 2 Compliance .................................................................................................................................................... 2 3 Normative references .................................................................................................................................... 2 4 Terms and definitions ................................................................................................................................... 3 5 The Face Image Record Format ................................................................................................................... 6 5.1 Overview ......................................................................................................................................................... 6 5.2 Data Conventions .......................................................................................................................................... 9 5.2.1 Byte ordering ................................................................................................................................................. 9 5.2.2 Numeric values .............................................................................................................................................. 9 5.2.3 Conversion to integer ................................................................................................................................... 9 5.2.4 Unspecified field value .................................................................................................................................. 9 5.2.5 Unknown field value ...................................................................................................................................... 9 5.3 The CBEFF Header ........................................................................................................................................ 9 5.4 The Facial Record Header .......................................................................................................................... 10 5.4.1 Format Identifier .......................................................................................................................................... 10 5.4.2 Version Number ........................................................................................................................................... 10 5.4.3 Length of Record ......................................................................................................................................... 10 5.4.4 Number of Facial Images ............................................................................................................................ 10 5.5 The Facial Information Block ..................................................................................................................... 10 5.5.1 Facial Record Data Length ......................................................................................................................... 11 5.5.2 Number of Feature Points ........................................................................................................................... 11 5.5.3 Gender .......................................................................................................................................................... 11 5.5.4 Eye Colour .................................................................................................................................................... 11 5.5.5 Hair Colour ................................................................................................................................................... 12 5.5.6 Property Mask .............................................................................................................................................. 12 5.5.7 Expression ................................................................................................................................................... 13 5.5.8 Pose Angle ................................................................................................................................................... 13 5.5.9 Pose Angle Uncertainty .............................................................................................................................. 15 5.6 The Landmark Point Block ......................................................................................................................... 15 5.6.1 Landmark Point Type .................................................................................................................................. 16 5.6.2 Landmark Point Code ................................................................................................................................. 16 5.6.3 MPEG4 Feature Points ................................................................................................................................ 16 5.6.4 Eye and nostril Landmark Points............................................................................................................... 17 5.6.5 Anthropometric Landmarks ....................................................................................................................... 18 5.6.6 Anthropometric 3D landmark ..................................................................................................................... 21 5.6.7 Z Coordinate ................................................................................................................................................. 21 5.7 The Image Information Block ..................................................................................................................... 22 5.7.1 Face Image Type .......................................................................................................................................... 22 5.7.2 Image Data Type .......................................................................................................................................... 23 5.7.3 Width ............................................................................................................................................................. 23 5.7.4 Height ............................................................................................................................................................ 23 5.7.5 Image Colour Space .................................................................................................................................... 23 5.7.6 Source Type ................................................................................................................................................. 23 5.7.7 Device Type .................................................................................................................................................. 24 5.7.8 Quality ........................................................................................................................................................... 24 5.8 The Image Data Block ................................................................................................................................. 24 5.8.1 Data structure .............................................................................................................................................. 24 5.9 The 3D Information Block ........................................................................................................................... 24 This is a preview - click here to buy the full publication
ISO/IEC 19794-5:2005(E) iv © ISO/IEC 2005 — All rights reserved 5.9.1 Length of 3D Data Representation ............................................................................................................. 25 5.9.2 Coordinate System Type ............................................................................................................................. 25 5.9.3 Texture Projection Matrix ............................................................................................................................ 27 5.9.4 ScaleX, ScaleY, ScaleZ, OffsetX, OffsetY, OffsetZ ................................................................................... 27 5.9.5 3D Representation Type .............................................................................................................................. 28 5.9.6 3D Supplemental Data ................................................................................................................................. 28 5.9.7 3D Source Type ............................................................................................................................................ 28 5.9.8 3D Device Type ............................................................................................................................................ 29 5.9.9 3D to 2D Image Temporal Synchronicity ................................................................................................... 29 5.9.10 3D to 2D Texture Temporal Synchronicity ................................................................................................ 29 5.9.11 3D Acquisition Time .................................................................................................................................... 30 5.9.12 2D Texture Acquisition Time ...................................................................................................................... 30 5.9.13 Texture Map Type ........................................................................................................................................ 30 5.9.14 Texture Map Spectrum ................................................................................................................................ 31 5.10 The 3D Data Block ....................................................................................................................................... 31 5.10.1 Range Image Bit Depth ................................................................................................................................ 31 5.10.2 Range Image ................................................................................................................................................. 32 5.10.3 3D Point Map Width and Height ................................................................................................................. 32 5.10.4 3D Point Map ................................................................................................................................................ 32 5.10.5 Vertex Data ................................................................................................................................................... 32 5.10.6 Triangle Data ................................................................................................................................................ 33 5.10.7 Error Map ...................................................................................................................................................... 33 5.10.8 Texture Map .................................................................................................................................................. 33 6 The Basic Face Image Type ........................................................................................................................ 34 6.1 Inheritance requirements for the Basic Face Image Type ....................................................................... 34 6.2 Image data encoding requirements for the Basic Face Image Type ...................................................... 34 6.3 Image data compression requirements for the Basic Face Image Type ................................................ 34 6.4 Format requirements for the Basic Face Image Type .............................................................................. 34 6.4.1 Facial Header ................................................................................................................................................ 34 6.4.2 Facial Information ........................................................................................................................................ 34 6.4.3 Image Information ........................................................................................................................................ 34 7 The Frontal Face Image Type ..................................................................................................................... 34 7.1 Inheritance requirements for the Frontal Face Image Type .................................................................... 34 7.2 Scene requirements for the Frontal Image Type ...................................................................................... 35 7.2.1 Purpose ......................................................................................................................................................... 35 7.2.2 Pose ............................................................................................................................................................... 35 7.2.3 Expression .................................................................................................................................................... 35 7.2.4 Assistance in positioning the face ............................................................................................................. 36 7.2.5 Shoulders...................................................................................................................................................... 36 7.2.6 Backgrounds ................................................................................................................................................ 36 7.2.7 Subject and scene lighting ......................................................................................................................... 36 7.2.8 Shadows over the face ................................................................................................................................ 36 7.2.9 Shadows in eye sockets .............................................................................................................................. 36 7.2.10 Hot spots ....................................................................................................................................................... 36 7.2.11 Eye glasses .................................................................................................................................................. 36 7.2.12 Eye patches .................................................................................................................................................. 36 7.3 Photographic Requirements for the Frontal Image Type ........................................................................ 37 7.3.1 Purpose ......................................................................................................................................................... 37 7.3.2 No over or under exposure ......................................................................................................................... 37 7.3.3 Focus and depth of field ............................................................................................................................. 37 7.3.4 Unnatural colour .......................................................................................................................................... 37 7.3.5 Colour or greyscale enhancement ............................................................................................................. 37 7.3.6 Radial distortion of the camera lens .......................................................................................................... 37 7.4 Digital requirements for the Frontal Image Type ...................................................................................... 37 7.4.1 Geometry ...................................................................................................................................................... 37 7.4.2 Colour profile ............................................................................................................................................... 38 7.4.3 Video interlacing .......................................................................................................................................... 38 7.5 Format requirements for the Frontal Image Type .................................................................................... 38 7.5.1 Inheritance requirements ............................................................................................................................ 38 This is a preview - click here to buy the full publication
ISO/IEC 19794-5:2005(E) © ISO/IEC 2005 — All rights reserved v 7.5.2 Image Information ....................................................................................................................................... 38 8 The Full Frontal Image Type ....................................................................................................................... 39 8.1 Inheritance requirements for the Full Frontal Face Image Type ............................................................ 39 8.2 Scene requirements for the Full Frontal Face Image Type ..................................................................... 39 8.3 Photographic requirements for the Full Frontal Face Image Type ........................................................ 39 8.3.1 Introduction .................................................................................................................................................. 39 8.3.2 Horizontally centred face ............................................................................................................................ 40 8.3.3 Vertical position of the face ........................................................................................................................ 40 8.3.4 Width of head ............................................................................................................................................... 40 8.3.5 Length of head ............................................................................................................................................. 40 8.3.6 Summary of photographic requirements .................................................................................................. 40 8.4 Digital requirements for the Full Frontal Face Image Type ..................................................................... 41 8.4.1 Resolution .................................................................................................................................................... 41 8.5 Format requirements for the Full Frontal Image Type ............................................................................. 41 8.5.1 Inheritance requirements ............................................................................................................................ 41 8.5.2 Image Information ....................................................................................................................................... 41 9 The Token Face Image Type ....................................................................................................................... 41 9.1 Inheritance requirements for Token Face Image Type ............................................................................ 41 9.2 Digital requirements for the Token Face Image Type .............................................................................. 42 9.2.1 Introduction .................................................................................................................................................. 42 9.2.2 Eye positions ............................................................................................................................................... 42 9.2.3 Token image geometric format .................................................................................................................. 42 9.2.4 Minimum width Token image ..................................................................................................................... 43 9.2.5 Padding ......................................................................................................................................................... 43 9.3 Format requirements for the Token Face Image Type ............................................................................ 43 9.3.1 Inheritance requirements ............................................................................................................................ 43 9.3.2 Image Information ....................................................................................................................................... 43 10. The Basic 3D Image Type ........................................................................................................................... 43 10.1 Inheritance Requirements for the Basic 3D Image Type ......................................................................... 43 10.2 The Basic 3D Image Type using the 3D Point Map representation ........................................................ 44 10.2.1 Coordinate System Type ............................................................................................................................ 44 10.2.2 ScaleX, ScaleY and ScaleZ ......................................................................................................................... 44 10.3 The Basic 3D Image Type using the 3D Vertex representation .............................................................. 44 10.3.1 Coordinate System Type ............................................................................................................................ 44 10.3.2 ScaleX, ScaleY and ScaleZ ......................................................................................................................... 44 11 The Full Frontal 3D Image Type ................................................................................................................. 44 11.1 Inheritance requirements ............................................................................................................................ 44 11.2 Coordinate System Type ............................................................................................................................ 44 11.3 Pose of the 3D representation .................................................................................................................... 44 11.4 Calibration Texture Projection Accuracy .................................................................................................. 45 11.5 Requirements on Full Frontal 3D Image Types using the Range Image Representation .................... 45 11.5.1 ScaleX, ScaleY and ScaleZ ......................................................................................................................... 45 11.5.2 Face Coverage ............................................................................................................................................. 45 11.5.3 Non-valid points in 3D data Image ............................................................................................................. 45 11.6 Requirements on Full Frontal 3D Image Types using the 3D Point Map Representation.................... 46 11.7 Requirements on Full Frontal 3D Image Types using the 3D Vertex Representation .......................... 46 12 The Token Frontal 3D Image Type ............................................................................................................. 46 12.1 General ......................................................................................................................................................... 46 12.2 Inheritance requirements ............................................................................................................................ 46 12.3 Requirements on Token Frontal 3D Image Types using the Range Image Representation ................ 47 12.4 Requirements on Token Frontal 3D Image Types using the 3D Point Map Representation ............... 47 12.5 Requirements on Token Frontal 3D Image Types using the Vertex Representation ........................... 47 Bibliography .............................................................................................................................................................. 48 Annex A ..................................................................................................................................................................... 49 A.1 Best practices for Basic Face Images ....................................................................................................... 49 A.1.1 Purpose ........................................................................................................................................................ 49 A.1.2 Feature Point determination ....................................................................................................................... 49 This is a preview - click here to buy the full publication
ISO/IEC 19794-5:2005(E) vi © ISO/IEC 2005 — All rights reserved A.2 Best practices for Frontal Images .............................................................................................................. 49 A.2.1 Purpose ......................................................................................................................................................... 49 A.2.2 Pose ............................................................................................................................................................... 49 A.2.3 Expression .................................................................................................................................................... 49 A.2.4 Assistance in positioning the face ............................................................................................................. 49 A.2.5 Background .................................................................................................................................................. 50 A.2.5.1 Background segmentation.......................................................................................................................... 50 A.2.5.2 Background shadows .................................................................................................................................. 50 A.2.5.3 Background uniformity ............................................................................................................................... 50 A.2.5.4 Background examples ................................................................................................................................. 50 A.2.6 Focus and depth of field ............................................................................................................................. 50 A.2.7 No unnatural colour ..................................................................................................................................... 50 A.2.8 Colour calibration ........................................................................................................................................ 50 A.2.9 Radial distortion of the camera lens .......................................................................................................... 50 A.3 Best practices for Full Frontal Images ...................................................................................................... 51 A.3.1 Digital attributes of Full Frontal Images .................................................................................................... 51 A.3.1.1 Photo resolution .......................................................................................................................................... 51 A.3.2 Best practices for use of Full Frontal Images on Travel Documents ..................................................... 51 A.3.2.1 Width to height ratio of the image .............................................................................................................. 51 A.3.2.2 Head size relative to the image size ........................................................................................................... 51 A.3.2.3 Summary of best practice photographic recommendations ................................................................... 51 A.3.2.4 Sample images and sample photograph taking guidelines for travel documents ............................... 53 A.3.3 Full Frontal Image compression ................................................................................................................ 56 A.3.3.1 Compression – no region of interest ......................................................................................................... 56 A.3.3.2 Recommendations for maximum compression and file sizes for JPEG and JPEG2000 ..................... 57 A.3.4 Full Frontal Image compression using region of interest ....................................................................... 57 A.3.4.1 Discussion .................................................................................................................................................... 57 A.3.4.2 Inner and outer regions, Full Image ........................................................................................................... 58 A.4 Best practices for Token Images ............................................................................................................... 58 A.4.1 Token image sizes ....................................................................................................................................... 58 A.4.2 Creation of a Token Image .......................................................................................................................... 59 A.4.3 Best practices for digital attributes of Token Images .............................................................................. 59 A.4.4 Token Image compression.......................................................................................................................... 60 A.4.4.1 Compression – no region of interest ......................................................................................................... 60 A.4.4.2 Recommendations for maximum compression and file sizes for JPEG and JPEG2000 Token Images ............................................................................................................................................... 61 A.4.5 Token Image compression using region of interest ................................................................................ 61 A.4.5.1 Discussion .................................................................................................................................................... 61 A.4.6 Inner and outer regions for the Token Image for the purpose of compression .................................... 62 A.5 Experimental study on the enrolment of full frontal images for travel documents .............................. 62 A.5.1 Software and data used for the analysis ................................................................................................... 62 A.5.2 Experimental results .................................................................................................................................... 63 A.5.2.1 Inter-eye distance ........................................................................................................................................ 63 A.5.2.2 Relative horizontal position of the face ..................................................................................................... 64 A.5.2.3 Relative vertical position of the face ......................................................................................................... 64 A.5.2.4 Head Image Width Ratio .............................................................................................................................. 65 A.5.2.5 Head Image Height Ratio ............................................................................................................................. 66 A.5.3 Error Discussion .......................................................................................................................................... 67 A.5.4 Summary ....................................................................................................................................................... 67 A.6 Study on the effects of inter-eye distance and roll on biometric comparison performance ............... 68 A.6.1 Inter-eye distance ........................................................................................................................................ 68 A.6.2 Pose ............................................................................................................................................................... 69 A.7 Best Practices for the Full Frontal 3D Image Type ................................................................................... 70 A.7.1 Best Practices for the 2D part of the Full Frontal 3D Image Type .......................................................... 70 A.7.2 Compatibility considerations ..................................................................................................................... 70 A.7.3 Pose of the 3D representation .................................................................................................................... 70 A.7.4 3D to 2D Image Temporal Synchronicity ................................................................................................... 71 A.7.5 3D Acquisition Time .................................................................................................................................... 71 A.7.6 Best Practices for Full Frontal 3D Image Types using the Range Image Representation ................... 71 A.7.6.1 ScaleX, ScaleY and ScaleZ ......................................................................................................................... 71 This is a preview - click here to buy the full publication
ISO/IEC 19794-5:2005(E) © ISO/IEC 2005 — All rights reserved vii A.7.6.2 Non-valid points in Range Image ............................................................................................................... 71 A.7.7 Best Practices for the Full Frontal 3D Image Types using the 3D Point Map Representation............................................................................................................................................. 71 A.7.7.1 3D Point Map Width and Height ................................................................................................................. 71 A.7.7.2 Face coverage .............................................................................................................................................. 71 A.7.8 Best Practices for Full Frontal 3D Image Types using the 3D Vertex Representation ......................... 71 A.7.8.1 Face coverage .............................................................................................................................................. 71 A.8 Best Practices for Token Frontal 3D Images ............................................................................................ 72 A.8.1 Best Practices for the 2D part of the Token Frontal 3D Image ............................................................... 72 A.8.2 Compatibility considerations ..................................................................................................................... 72 A.8.3 Pose of the 3D representation .................................................................................................................... 72 A.8.4 3D to 2D Image Temporal Synchronicity .................................................................................................. 72 A.8.5 3D Acquisition Time .................................................................................................................................... 72 A.8.6 Best Practices for Token Frontal 3D Image Types using the Range Image Representation .............. 72 A.8.7 Best Practices for Token Frontal 3D Image Types using the 3D Point Map Image Representation............................................................................................................................................. 72 A.8.8 Best Practices for Token Frontal 3D Image Types using the Vertex Representation .......................... 72 A.9 Summary of mandatory and best practices for the 3D Image Types ..................................................... 72 Annex B ..................................................................................................................................................................... 75 B.1 Scope ............................................................................................................................................................ 75 B.2 Photography recommendations ................................................................................................................ 75 B.2.1 General ......................................................................................................................................................... 75 B.2.2 Recommendations for a photo studio or store ........................................................................................ 75 B.2.3 Recommendations for photo booths ........................................................................................................ 79 B.2.4 Recommendations for a registration office environment ....................................................................... 83 B.3 Guidelines for printing ................................................................................................................................ 84 B.3.1 General ......................................................................................................................................................... 84 B.3.2 Spatial and tonal resolution trade-offs ...................................................................................................... 85 B.3.3 Recommended printing quality .................................................................................................................. 85 B.3.4 Use of a photo template .............................................................................................................................. 86 B.4 Guidelines for scanning .............................................................................................................................. 86 B.4.1 General ......................................................................................................................................................... 86 B.4.2 Sampling frequency and quantization levels ........................................................................................... 87 B.4.3 Spatial resolution ........................................................................................................................................ 87 B.4.4 Output colour space .................................................................................................................................... 87 B.4.5 Saturation ..................................................................................................................................................... 87 B.4.6 Image compression ..................................................................................................................................... 87 B.5 Face image quality assessment software ................................................................................................. 87 B.6 Tables of the recommendations ................................................................................................................ 89 B.6.1 General ......................................................................................................................................................... 89 B.6.2 Scene setting ............................................................................................................................................... 89 B.6.3 Photographing ............................................................................................................................................. 91 B.6.4 After photographing .................................................................................................................................... 91 B.6.5 Photographic quality ................................................................................................................................... 92 B.7 Experimental data ........................................................................................................................................ 93 B.7.1 Experimental results of face recognition in a photo studio and photo booth ...................................... 93 B.8 Photographic examples .............................................................................................................................. 94 B.8.1 General ......................................................................................................................................................... 94 B.8.2 Photographic examples at a photo studio ................................................................................................ 94 B.8.3 Photographic examples at a photo booth ................................................................................................. 99 Annex C ................................................................................................................................................................... 104 This is a preview - click here to buy the full publication
viii © ISO/IEC 2005 — All rights reservedISO/IEC 19794-5:2005(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. In the field of information technology, ISO and IEC have established a joint technical committee, ISO/IEC JTC 1. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2. The main task of the joint technical committee is to prepare International Standards. Draft International Standards adopted by the joint technical committee are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO and IEC shall not be held responsible for identifying any or all such patent rights. This consolidated reprint of ISO/IEC 19794-5:2005 was prepared by Joint Technical Committee ISO/IEC JTC1, Information Technology, Subcommittee SC 37, Biometrics. This consolidated reprint of ISO/IEC 19794-5:2005 contains the original content of ISO/IEC 19794-5:2005 and incorporates the Amendments ISO/IEC 19794-5:2005/Amd 1:2007 and ISO/IEC 19794-5:2005/Amd 2:2009 and the Technical Corrigenda ISO/IEC 19794-5:2005/Cor 1:2008, ISO/IEC 19794-5:2005/Cor 2:2008, ISO/IEC 19794-5:2005/Cor 3:2013, ISO/IEC 19794-5:2005/Cor 4:2015, and the unpublished draft of ISO/IEC 19794-5:2005/Cor 5. This is a preview - click here to buy the full publication
ISO/IEC 19794-5:2005(E) © ISO/IEC 2005 — All rights reserved ix Introduction Face images, also commonly referred to as displayed portraits, have been used for many decades to verify identity of persons. In recent years, digital face images are used in many applications including human examination as well as computer automated face recognition. Although photographic formats have been standardized in some cases such as passport and driver license, it is also demanded to define a standard data format of digital face images to allow interoperability among vendors. This document is intended to provide a face image format for face recognition applications requiring exchange of face image data. The typical applications are: Human examination of facial images with sufficient resolution to allow a human examiner to ascertain small features such as moles and scars that might be used to verify identity; Human verification of identify by comparison of persons against facial images; Computer automated face identification (one-to-many searching); Computer automated face verification (one-to-one matching). To enable many applications on variety of devices, including devices that have the limited resources required for data storage, and to improve face recognition accuracy, this document specifies not only a data format, but also scene constraints (lighting, pose, expression, etc.), photographic properties (positioning, camera focus, etc.), digital image attributes (image resolution, image size, etc.). Several image types are introduced to define categories that satisfy requirements of some applications. Each requirement is specified for each image type. The record format specified in this document is designed to be embedded in a CBEFF-compliant structure specified in the multi-part Standard ISO/IEC 19785. The embedment in the CBEFF structure is described in ISO/IEC 19794-1:2006. This is a preview - click here to buy the full publication
INTERNATIONAL STANDARD ISO/IEC 19794-5:2005(E) © ISO/IEC 2005 — All rights reserved 1 Information technology – Biometric data interchange formats – Face image data 1 Scope This document specifies A record format for storing, recording, and transmitting the information from one or more facial images within a CBEFF data structure, Scene constraints of the facial images, Photographic properties of the facial images, Digital image attributes of the facial images. Each requirement is specified for the following Face Image Types, respectively. Basic: This is the fundamental Face Image Type that specifies a record format including header and image data. All Face Image Types adhere to the properties of this type. No mandatory scene, photographic and digital requirements are specified for this image type. Frontal: A Basic Face Image Type that adheres to additional requirements appropriate for frontal face recognition and/or human examination. Two types of Frontal Face Image Types are defined in this document, Full Frontal and Token Frontal (or simply Token). Full Frontal: A Face Image Type that specifies frontal images with sufficient resolution for human examination as well as reliable computer face recognition. This type of Face Image Type includes the full head with all hair in most cases, as well as neck and shoulders. This image type is suitable for permanent storage of the face information, and it is applicable to portraits for passport, driver license, and “mug shot” images. Token Frontal: A Face Image Type that specifies frontal images with a specific geometric size and eye positioning based on the width and height of the image. This image type is suitable for minimizing the storage requirements for computer face recognition tasks such as verification while still offering vendor independence and human verification (versus human examination which requires more detail) capabilities. Table 1 shows the relationships between Face Image Types using the notion of inheritance. For example, Frontal inherits properties from Basic, which means that all normative Clauses that apply to Basic also apply to Frontal. Table 1 – Inheritance of Face Image Types Face Image Type Inherits from Normative Clauses Informative Clauses Basic None 1, 2, 3, 4, 5, 6 A.1 Frontal Basic 7 A.2 Full Frontal Frontal 8 A.3 Token Frontal 9 A.4 This is a preview - click here to buy the full publication
ISO/IEC 19794-5:2005(E) 2 © ISO/IEC 2005 — All rights reserved Figure 1 gives a general overview of the scene, photographic, digitization, and format requirements for the face image types specified in this document. The Basic Face Image Type has no scene, photographic, or digital requirements. RequirementsScene PhotographicDigitalFormat Lighting Image and Subject Positioning Camera Attributes Digital Camera Analogue to Digital Image Scanning Digital Specifications Record Format and Organization Clauses: Clauses: Clauses: Clauses: Basic Face Frontal Face Full Frontal Face None 7.2 8.2 Basic Face Frontal Face Full Frontal Face None 7.3 8.3 Basic Face Frontal Face Full Frontal Face Token Face None 7.4 8.4 9.2 Basic Face Frontal Face Full Frontal Face Token Face 5 6.2 6.3 6.4 7.5 8.5 9.3 Figure 1 – Types of imaging requirements specified in this document. 2 Compliance Conformity with this document requires compliance with the record format specification defined in Clauses 5 and the Basic Face Image Type defined in Clause 6. In addition, this document defines additional Face Image Types. Compliance with the Full Frontal Face Image Type requires compliance with Clauses 5, 6, 7, and 8. Conformity with the Token Frontal Image Type requires additional compliance with Clause 5, 6, 7, and 9. 3 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO/IEC 19785 Information technology -- Common Biometric Exchange Formats Framework – Multi-part Standard ISO/IEC 19794-1:2006 Information technology — Biometric data interchange formats — Part 1: Framework This is a preview - click here to buy the full publication
ISO/IEC 19794-5:2005(E) © ISO/IEC 2005 — All rights reserved 3 ISO/IEC 10918-1, Information technology — Digital compression and coding of continuous-tone still images: Requirements and guidelines ISO/IEC 15444-1, Information technology — JPEG 2000 image coding system: Core coding system C-Cube Microsystems, JPEG File Interchange Format (JFIF), Version 1.02 PIMA 7667:2001, Photography – Electronic Still Picture Imaging – Extended sRGB Color Encoding – e-sRGB ICC.1:2001-12, File Format for Color Profiles ISO/IEC 14496-2:2004, Information technology - Coding of audio-visual objects - Part 2: Visual (MPEG4) ISO/IEC 15948:2004, Information technology — Computer graphics and image processing — Portable Network Graphics (PNG): Functional specification 4 Terms and definitions For the purposes of this document, the terms and definitions given in ISO/IEC 19794-1:2006 and the following apply. 4.1 chin The central forward portion of the lower jaw. 4.2 colour image Continuous tone image that has more than one channel, each of which is coded with one or multiple bits. 4.3 colour space A way of representing colours of pixels in an image. For instance, RGB, YUV and greyscale are typically used in this document. 4.4 common biometric exchange formats framework, CBEFF Data format specifically for exchanging biometric data that provides for the encompassing of any biometric type into a standard format. 4.5 continuous tone image Image whose channels have more than one bit per pixel. 4.6 crown Top of the head, or (if obscured by hair or headwear), where the top of the head/skull would be if it could be seen. 4.7 dots per inch, DPI, dpi Measurement of scanner and printer resolution. 4.8 facial image Electronic image-based representation of the portrait of a person. This is a preview - click here to buy the full publication |