1、BRITISH STANDARD BS ISO/IEC 19794-3:2006 Information technology Biometric data interchange formats Part 3: Finger pattern spectral data ICS 35.040 BS ISO/IEC 19794-3:2006 This British Standard was published under the authority of the Standards Policy and Strategy Committee on 29 September 2006 BSI 2
2、006 ISBN 0 580 49200 1 National foreword This British Standard was published by BSI. It is the UK implementation of ISO/IEC 19794-3:2006. The UK participation in its preparation was entrusted to Technical Committee IST/44, Biometrics. A list of organizations represented on IST/44 can be obtained on
3、request to its secretary. This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. Compliance with a British Standard cannot confer immunity from legal obligations. Amendments issued since publication Amd. No. Date Co
4、mments Reference number ISO/IEC 19794-3:2006(E)INTERNATIONAL STANDARD ISO/IEC 19794-3 First edition 2006-08-15 Information technology Biometric data interchange formats Part 3: Finger pattern spectral data Technologies de linformation Formats dchange de donnes biomtriques Partie 3: Donnes spectrales
5、 de la forme du doigt BS ISO/IEC 19794-3:2006ii iii Contents Page Foreword. v Introduction . vi 1 Scope. 1 2 Conformance. 1 3 Normative references. 1 4 Terms and definitions. 1 5 Symbols and abbreviated terms . 4 6 Data conventions 5 6.1 Byte and bit ordering 5 6.2 Coordinate system 5 6.3 Greyscale
6、precision 6 6.4 Image polarity 6 6.5 Angle direction of rotation. 6 6.6 Phase and propagation angles 6 7 Determination of finger pattern spectral data 6 7.1 Overview 6 7.2 Step 0) Optional Image pre-processing . 6 7.3 Step 1) Cellular partitioning. 6 7.4 Step 2) Spectral component selection 7 7.4.1
7、Quantized co-sinusoidal triplets . 7 7.4.2 Discrete Fourier Transform . 10 7.4.3 Gabor filters. 12 7.5 Quality 13 8 Finger pattern spectral data record 14 8.1 Record header. 14 8.1.1 Format identifier 14 8.1.2 Version number. 15 8.1.3 Length of record . 15 8.1.4 Number of single finger records . 15
8、8.1.5 x (horizontal) resolution . 15 8.1.6 y (vertical) resolution 15 8.1.7 Number of cells in x-direction . 15 8.1.8 Number of cells in y-direction 15 8.1.9 Number of pixels in cells in x-direction 15 8.1.10 Number of pixels in cells in y-direction 15 8.1.11 Number of pixels between cell centres in
9、 x-direction. 15 8.1.12 Number of pixels between cell centres in y-direction. 16 8.1.13 Spectral component selection method. 16 8.1.14 Type of window. 16 8.1.15 Standard deviation 16 8.1.16 Number of frequencies. 17 8.1.17 Frequencies. 17 8.1.18 Number of orientations 17 8.1.19 Number of spectral co
10、mponents to be retained per cell 17 8.1.20 Bit-depth of propagation angle of co-sinusoidal function . 18 8.1.21 Bit-depth of wavelength of co-sinusoidal function . 18 8.1.22 Bit-depth of phase 18 8.1.23 Bit-depth of magnitude. 18 BS ISO/IEC 19794-3:2006iv 8.1.24 Bit-depth of quality score. 18 8.1.25
11、 Cell quality group granularity 19 8.1.26 Reserved bytes 19 8.2 Single finger record 19 8.2.1 Header 19 8.2.2 Finger pattern spectral data block 20 8.2.3 Extended data block . 23 8.3 Summary of finger pattern spectral data record28 9 Finger pattern spectral data card format 31 Annex A (informative)
12、Finger pattern spectral data record examples quantized co-sinusoidal triplet spectral component selection method 33 A.1 Example 1. 33 A.2 Example 2. 34 A.3 Size comparisons 36 Annex B (informative) Finger pattern spectral data record examples Discrete Fourier Transform spectral component selection m
13、ethod .37 B.1 Example 1. 37 B.2 Example 2. 38 Annex C (informative) Finger pattern spectral data record example Gabor filter spectral component selection method 40 Bibliography . 42 BS ISO/IEC 19794-3:2006v Foreword ISO (the International Organization for Standardization) and IEC (the International
14、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 t
15、echnical 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 te
16、chnical 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
17、 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. ISO/IEC 19794-3 was prepared by Joint Technical Committee ISO/IEC JTC 1, Information technology, Subcommittee SC 37, Biometrics. ISO/IEC 19794
18、 consists of the following parts, under the general title Information technology Biometric data 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 ti
19、me series data Part 8: Finger pattern skeletal data Part 9: Vascular image data Part 10: Hand geometry silhouette data Part 11: Signature/sign processed dynamic data BS ISO/IEC 19794-3:2006vi Introduction In the interest of implementing interoperable personal biometric recognition systems, this part
20、 of ISO/IEC 19794 establishes a data interchange format for finger pattern spectral data. The goal of this part of ISO/IEC 19794 is to allow the exchange of local or global spectral data derived from a fingerprint image without the exchange of the entire image. This will allow more compact data repr
21、esentations. This part of ISO/IEC 19794 allows for representation of spectral components, such as Discrete Fourier Transform and (single-scale) Gabor Filter components, extracted from global or stationary (not image dependent and not varying over the image) local overlapping or non-overlapping unifo
22、rm-sized regions of the original intensity (non-color) image. Some or all of the extracted spectral components will be stored in the data format, depending upon the implementation. This part of ISO/IEC 19794 does not accommodate multi-scale (wavelet) decompositions. There are fingerprint recognition
23、 algorithms that use spectral data directly for pattern matching. Spectral data- based recognition algorithms process “globally” local sections (cells) of biometric images, in contrast to morphological-based algorithms, which extract singularities in the morphological features. At the current time,
24、there is no established mechanism for the interchange of finger pattern spectral information for use with spectral-based fingerprint matching algorithms. By establishing a standard for spectral-based representation of fingerprints, we allow interoperability among fingerprint recognition vendors base
25、d on a small data record; support the proliferation of low-cost commercial fingerprint sensors with limited coverage, dynamic range, or resolution; define a data record that can be used to store biometric information on a variety a storage mediums (including, but not limited to, portable devices and
26、 smart cards); encourage the adoption of biometrics in applications where interoperability is required. The International Organization for Standardization (ISO) and the International Electrotechnical Commission (IEC) draw attention to the fact that it is claimed that compliance with this document ma
27、y involve the use of patents concerning the quantized co-sinusoidal triplets method of formatting the pattern spectral data. ISO and IEC take no position concerning the evidence, validity and scope of this patent right. The holder of this patent right has assured the ISO and IEC that he/she is willi
28、ng to negotiate licenses under reasonable and non-discriminatory terms and conditions with applications throughout the world. In this respect, the statement of the holder of this patent right is registered with ISO and IEC. Information may be obtained from: Bioscrypt Inc. 505 Cochrane Drive Markham,
29、 Ontario, Canada L3R 8E3 Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights other than those identified above. ISO and IEC shall not be held responsible for identifying any or all such patent rights. BS ISO/IEC 19794-3:20061 Informati
30、on technology Biometric data interchange formats Part 3: Finger pattern spectral data 1 Scope This part of ISO/IEC 19794 specifies the interchange format for the exchange of spectral-based fingerprint data. 2 Conformance A biometric system or algorithm conforms to this part of ISO/IEC 19794 if it sa
31、tisfies the mandatory requirements for the generation of the finger pattern spectral data as defined in Clause 7 and the generation of the data record as described in Clause 8. 3 Normative references The following referenced documents are indispensable for the application of this document. For dated
32、 references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO/IEC 19784-1:2006, Information technology Biometric application programming interface Part 1: BioAPI specification ISO/IEC 19785-1:2006, Informati
33、on technology Common Biometric Exchange Formats Framework Part 1: Data element specification ANSI/NIST-ITL 1:2000, Standard Data Format for the Interchange of Fingerprint, Facial, optionally extracting biometric features from that acquired biometric sample; comparing the biometric features (or acqui
34、red biometric sample) with those contained in one or more reference templates or models; deciding how well they match; and indicating whether or not a recognition has been made. 4.7 bit-depth the number of bits used to represent a data record parameter 4.8 cell designated array of pixels within a fi
35、nger pattern NOTE Multi-scale cells are not accommodated in this part of ISO/IEC 19794. BS ISO/IEC 19794-3:20063 4.9 cell structure an array of pixels, each of which has a greyscale value, defined by a co-sinusoidal pattern with parameters , , and NOTE This concept applies only to the quantized co-s
36、inusoidal triplet method. 4.10 cell quality group square array of cells of a finger pattern for which a quality score is specified 4.11 comparison the process of measuring the similarity or difference between the biometric features of an acquired biometric sample and a previously stored reference te
37、mplate or model 4.12 core a singular point in the fingerprint where the curvature of the ridges reaches a maximum NOTE For simplicity, the core can be considered as a U-turn, sometimes enclosing a few ridge endings. It serves as an approximation of the centre of the fingerprint image. 4.13 crop remo
38、ve the outer regions of an image to reduce the size 4.14 delta that point on a ridge at or nearest to the point of divergence of two typelines, and located at or directly in front of the point of divergence 4.15 dimension number of pixels in an acquired biometric sample image either x or y direction
39、 4.16 down-sample reduce the resolution of an image by re-sampling the image with a reduced number of pixels NOTE Proper filtering is implied to prevent aliasing. 4.17 enrolment the process of collecting acquired biometric samples from an individual and the subsequent preparation and storage of biom
40、etric reference templates or models 4.18 finger pattern fingerprint image that may be processed (by cropping and/or down-sampling, for example) NOTE For the purpose of this document, the concept of a finger pattern relates to an intermediate biometric sample. 4.19 finger pattern spectral data set of
41、 spectral components derived from a finger pattern BS ISO/IEC 19794-3:20064 4.20 minimal spatial wavelength the (spatial) wavelength (measured in pixels) at which exactly two samples of an image span a complete period of a (co)sinusoidal pattern NOTE This is therefore the maximal spatial frequency t
42、hat can be supported by a sampling resolution, and is known as the Nyquist frequency. The minimal spatial wavelength is the inverse of the Nyquist frequency. Be aware the minimum Nyquist frequency is established by the resolution of the down-sampled fingerprint image. The required resolution for any
43、 subpopulation should be determined according to the application. 4.21 pad embed an image in a larger array (usually filled with zeroes) to produce a resulting image of greater dimension 4.22 re-sampling sample an image at a different frequency from that used to sample the original image 4.23 resolu
44、tion number of pixels per unit length NOTE Pixels per cm (ppcm) will be used in this part of ISO/IEC 19794 as the units of resolution. Note that 1 pixel per cm (ppcm) = 2.54 pixels per inch (ppi). 4.24 typeline two innermost ridges that start parallel, diverge and surround or tend to surround the pa
45、ttern area 5 Symbols and abbreviated terms For the purposes of this document, the following symbols and abbreviated terms apply. 2D two dimensional CBEFF Common Biometric Exchange Formats Framework DFT Discrete Fourier Transform ppcm pixels per centimetre ppi pixels per inch Variables are represente
46、d in this document by: a, b, c, S, T italicized, lower and upper case letters , , ,., italicized, lower and upper case Greek letters a, b) range of values from (and including) a up to (but not including) b a, b range of values from (and including) a up to (and including) b a largest integer less than or equal to a a smallest integer greater than or equal to a BS ISO/IEC 19794-3:2006
