ANSI INCITS ISO IEC 19794-6-2011 Information technology - Biometric data interchange formats - Part 6 Iris image data.pdf

1、 INCITS/ISO/IEC 19794-6:2011 2013 ISO/IEC 19794-6:2011 Information technology Biometric data interchange formats Part 6: Iris image data INCITS/ISO/IEC 19794-6:2011 2013 PDF disclaimer This PDF file may contain embedded typefaces. In accordance with Adobes licensing policy, this file may be printed

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4、table for use by ISO member bodies. In the unlikely event that a problem relating to it is found, please inform the Central Secretariat at the address given below. Adopted by INCITS (InterNational Committee for Information Technology Standards) as an American National Standard. Date of ANSI Approval

5、: 6/26/2013 Published by American National Standards Institute, 25 West 43rd Street, New York, New York 10036 Copyright 2013 by Information Technology Industry Council (ITI). All rights reserved. These materials are subject to copyright claims of International Standardization Organization (ISO), Int

6、ernational Electrotechnical Commission (IEC), American National Standards Institute (ANSI), and Information Technology Industry Council (ITI). Not for resale. No part of this publication may be reproduced in any form, including an electronic retrieval system, without the prior written permission of

7、ITI. All requests pertaining to this standard should be submitted to ITI, 1250 Eye Street NW, Washington, DC 20005. Printed in the United States of America ii ITIC 2013 All rights reserved ISO/IEC 19794-6:2011(E) ISO/IEC 2011 All rights reserved iiiContents Page Foreword iv Introduction . v 1 Scope

8、1 2 Conformance . 1 3 Normative references 2 4 Terms and definitions . 2 5 Symbols and abbreviated terms 3 6 Iris image content specification . 3 6.1 General . 3 6.2 Uncropped Iris Image 4 6.3 VGA Iris Image . 4 6.4 Cropped Iris Image 5 6.5 Cropped and Masked Iris Image 6 7 Iris image format specifi

9、cation 7 7.1 General . 7 7.2 Iris image biometric data record 7 7.3 Iris general header structure 8 7.4 Iris representation header structure 8 7.5 Representation body . 12 8 Registered Format Type Identifier . 12 Annex A (normative) Conformance testing methodology 14 Annex B (informative) Iris image

10、 capture . 15 Bibliography 19 ISO/IEC 19794-6:2011(E) iv ISO/IEC 2011 All rights reservedForeword ISO (the International Organization for Standardization) and IEC (the International Electrotechnical Commission) form the specialized system for worldwide standardization. National bodies that are membe

11、rs 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 orga

12、nizations, 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/IE

13、C 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 national bodies for voting. Publication as an International Standard requires approval by at least 75 %

14、 of the national 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. ISO/IEC 19794-6 was prepared by Joint Technical Commi

15、ttee ISO/IEC JTC 1, Information technology, Subcommittee SC 37, Biometrics. This second edition cancels and replaces the first edition (ISO/IEC 19794-6:2005), which has been technically revised. ISO/IEC 19794 consists of the following parts, under the general title Information technology Biometric d

16、ata interchange formats: Part 1: Framework Part 2: Finger minutiae data Part 3: Finger pattern spectral data Part 4: Finger image data Part 5: Face image data Part 6: Iris image data Part 7: Signature/sign time series data Part 8: Finger pattern skeletal data Part 9: Vascular image data Part 10: Han

17、d geometry silhouette data Part 11: Signature/sign processed dynamic data Part 13: Voice data Part 14: DNA data ISO/IEC 19794-6:2011(E) ISO/IEC 2011 All rights reserved vIntroduction The purpose of this part of ISO/IEC 19794 is to define a standard for exchange of iris image information. This part o

18、f ISO/IEC 19794 contains a specific definition of attributes, a data record format for storing and transmitting the iris image and certain attributes, and conformance criteria. Currently, exchange of iris information between equipment from different vendors can be done using images of the eye. While

19、 some applications can successfully operate with full size uncompressed rectilinear images, there are others for which this is expensive with respect to storage and bandwidth. To provide interoperability among vendors, this part of ISO/IEC 19794 also defines compact representations of the human iris

20、. This part of ISO/IEC 19794 revises ISO/IEC 19794-6:2005 for interoperable iris data formats. The revision has focused mainly on three sets of issues: (1) compact image data formats; (2) acceptable compression targets and algorithms; and (3) specification of data to be included in records and recor

21、d headers in coordination with harmonization efforts across all the parts of ISO/IEC 19794, replacing the former header structures. Before this revision, the standard iris image format was a 307 kB image array (640 x 480), with optional JPEG compression (ISO/IEC 10918), but the recommended maximum c

22、ompression factor was set arbitrarily at 6:1 (ISO/IEC 19794-6:2005, A.1.6). Meanwhile, academic papers appeared 5 showing that the 307 kB image size could be reduced by about a factor of 150:1, to around 2 kB, with minimal impairment, provided that JPEG2000 (ISO/IEC 15444) was the compression algori

23、thm used, not JPEG (ISO/IEC 10918), and also that cropping and region-of-interest masking was used. Small payload storage devices (e.g. ISO/IEC 7816 smartcard), and limited bandwidth transmission protocols, mandated that iris images be reduced to a few kB. ISO/IEC 19794-6:2005 had attempted to provi

24、de for this by polar sampling of iris pixels, but vulnerabilities and defects in polar methods were pointed out and so in January 2008, WG3 voted to remove the old polar formats. NIST offered to undertake an extensive, independent, empirical investigation of various proposals and compressibility cla

25、ims, producing in late 2009 the Interoperable Iris Exchange (“IREX-1”) Report 8. The new image data formats in this part of ISO/IEC 19794 are based empirically on the IREX-1 conclusions. In addition to the two new compact formats, iris images are also amenable to lossless compression. The lossless P

26、NG standard, ISO/IEC 15948, may be applied to preserve completely the iris texture while affording iris image sizes in the range of 20 kB to 70 kB, well below those achievable for uncompressed images. In addition, Annex A, when published as Amendment 1 of this part of ISO/IEC 19794, will include nor

27、mative assertions for testing conformance of iris image records. Annex B of this part of ISO/IEC 19794 gives recommendations on iris image capture. While the data structure advanced here is syntactically incompatible with the previous version, software implementations can differentiate the records b

28、y inspecting the version number in the second four bytes of the record. INTERNATIONAL STANDARD ISO/IEC 19794-6:2011(E) ISO/IEC 2011 All rights reserved 1Information technology Biometric data interchange formats Part 6: Iris image data 1 Scope This part of ISO/IEC 19794 specifies iris image interchan

29、ge formats for biometric enrolment, verification and identification systems. The image information might be stored as an array of intensity values optionally comp ressed with ISO/IEC 15948 or ISO/IEC 15444, or an array of intensity values optionally compre ssed with ISO/IEC 15948 or ISO/IEC 15444 th

30、at might be cropped around the iris, with the iris at the centre, and which might incorporate region-of-interest masking of non-iris regions. This part of ISO/IEC 19794 does not establish requirements on the optical spec ifications of cameras, or requirements on photometric prope rties of iris image

31、s, or requirements on enrolment processes, workflow and use of iris equipment. 2 Conformance A biometric data record conforms to this part of ISO/IEC 19794 if it satisfies all of the normative requirements related to its data structure, data values and the relationships between its data elements, as

32、 specified throughout Clause 7 of this part of ISO/IEC 19794, and the relation ship between its data values and the input biometric data from which the biometric data record was generated, as specified throughout Clause 6 of this part of ISO/IEC 19794. A system that produces biometric data records i

33、s conformant to this part of ISO/IEC 19794 if all biometric data records that it outputs conform to this part of ISO/IEC 19794 (as defined above) as claimed in the Implementation Conformance Statement (ICS) associated with that system. A system does not need to be capable of producing biometric data

34、 records that cover all possible aspects of this part of ISO/IEC 19794, but only those that are claimed to be supported by the system in the ICS. The test for output record conformance shall be conducted in accordance with the normative content of Annex A. A system that uses biometric data records i

35、s conformant to this part of ISO/IEC 19794 if it can read, and use for the purpose intended by that system, all biometric data records that conform to this part of ISO/IEC 19794 (as defined above) as claimed in the ICS associated with that system. A system does not need to be capable of using biomet

36、ric data records that cover all possible aspects of this part of ISO/IEC 19794, but only those that are claimed to be supported by the system in an ICS. ISO/IEC 19794-6:2011(E) 2 ISO/IEC 2011 All rights reserved3 Normative references The following referenced documents are indispensable for the appli

37、cation 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 15444-1, Information technology JPEG 2000 image coding system: Core coding system ISO/IEC 15948:2004, Infor

38、mation technology Computer graphics and image processing Portable Network Graphics (PNG): Functional specification ISO/IEC 19794-1, Information technology Biometric data interchange formats Part 1: Framework 4 Terms and definitions For the purposes of this document, the terms and definitions given i

39、n ISO/IEC 19794-1 and the following apply. 4.1 grey scale continuous-tone image that has one component, which is luminance 4.2 iris coloured annular structure in the front portion of the eye comprised of muscular and connective tissue and pigmented layers, that defines the pupil and controls its siz

40、e 4.3 iris centre centre of a circle modelling the boundary between iris and sclera 4.4 iris radius radius of a circle modelling the boundary between iris and sclera 4.5 limbus outer boundary of the iris where it is joined to the sclera 4.6 margin distance in an image from the iris-sclera border, wh

41、en modelled as a circle, to the closest image border, expressed in pixels NOTE Throughout this part of ISO/IEC 19794, margins are defined in terms of the iris radius R. When written as an ordered pair, the order is (horizontal, vertical). EXAMPLE (0,6R, 0,2R) indicates that for an iris radius of R,

42、there shall be margins of image data 0,6R to the right and left of the iris and 0,2R above and below the iris. 4.7 Modulation Transfer Function ratio of the image modulation to the object modulation as a function of spatial frequency 4.8 pupil optical opening in the centre of the eye that serves as

43、a variable light aperture and defines the inner boundary of the iris ISO/IEC 19794-6:2011(E) ISO/IEC 2011 All rights reserved 34.9 pupil centre average of coordinates of all the pixels lying on the boundary of the pupil and the iris 4.10 round mathematical function applied to a number x such that ro

44、und(x) is the integer that is closest in value to x 4.11 sclera generally white wall of the eye peripheral to the iris 4.12 spatial frequency measure of the repetition rate of a sinusoidal intensity pattern in space, in units of cycles/deg or of cycles/mm at a given target range 5 Symbols and abbrev

45、iated terms For the purposes of this document, the following abbreviated terms apply. BDIR Biometric Data Interchange Record JPEG2000 Joint Photographic Experts Group enhanced compression standard for images as defined in ISO/IEC 15444 PNG Portable Network Graphics lossless compression standard for

46、images as defined in ISO/IEC 15948:2004 VGA Video Graphics Array image format having width 640 pixels and height 480 pixels 6 Iris image content specification 6.1 General This clause establishes requirements on the semantic content of the images that are allowed by this part of ISO/IEC 19794. These

47、requirements relate to the geometric structure, pre-processing, compression protocol, format, and dimensions of the image data. (Guidance on iris image capture is given in Annex B.) Image data may be uncompressed or compressed. If uncompressed then it shall be represented as a two-dimensional array

48、of monochrome pixels, organised in row-major order, with the lowest address corresponding to the upper left corner of the image. All uncompressed raw images shall have an 8 bit pixel depth. Images having a pixel depth other than 8 bits shall be encoded using PNG or JPEG2000. The remaining subclauses

49、 of clause 6 group these requirements according to the type of image. As shown in Table 1, four image types are defined according to a hierarchy inherited from an unconstrained abstract basic iris image. The associated type values are provided in clause 7.4.1. The requirements of clause 7 establish the encoding specifications for the image and its associated metadata. NOTE The specifications of image type