ISO/IEC 19784-4:2011
(Main)Information technology — Biometric application programming interface — Part 4: Biometric sensor function provider interface
Information technology — Biometric application programming interface — Part 4: Biometric sensor function provider interface
ISO/IEC 19784-4:2011 specifies a biometric sensor interface for a Biometric Service Provider (BSP, see ISO/IEC 19784-1). The interface supports a BSP wishing to provide the BioAPI Service Provider Interface (SPI) functions, whilst removing device handling activity from the BSP. ISO/IEC 19784-4:2011 provides an interface that can be used by all types of biometric sensor, including inter alia image streaming sensors (infrared, face, iris, finger, etc.), voice streaming sensors and digital tablets providing dynamic signature data. It is not in the scope of ISO/IEC 19784-4:2011 to define security and privacy requirements for capturing and transferring of biometric data across the Sensor Function Provider Interface (SFPI).
Technologies de l'information — Interface de programmation d'applications biométriques — Partie 4: Interface du fournisseur de fonction du capteur biométrique
General Information
Standards Content (Sample)
INTERNATIONAL ISO/IEC
STANDARD 19784-4
First edition
2011-03-01
Information technology — Biometric
application programming interface —
Part 4:
Biometric sensor function provider
interface
Technologies de l'information — Interface de programmation
d'applications biométriques —
Partie 4: Interface du fournisseur de fonction du capteur biométrique
Reference number
ISO/IEC 19784-4:2011(E)
©
ISO/IEC 2011
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ISO/IEC 19784-4:2011(E)
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ISO/IEC 19784-4:2011(E)
Contents Page
Foreword .v
Introduction.vi
1 Scope.1
2 Conformance.1
3 Normative references.1
4 Terms and definitions .1
5 Symbols, abbreviated terms, data structure definitions and error codes.2
5.1 Symbols and abbreviated terms .2
5.2 Data structure definitions and error codes.2
6 Interface architecture.3
7 Selecting and loading BFPs and BioAPI_Units.4
7.1 Obtaining information about BFPs and BioAPI_Units .4
7.2 Loading BFPs .5
7.2.1 Loading BFPs when attaching to an unspecified BioAPI_Unit .5
7.2.2 Loading BFPs when attaching to a specific BioAPI_Unit .5
8 BSFPI Definition .5
8.1 BSFPI data structures.5
8.1.1 Control codes .5
8.1.2 BioSFPI_EventHandler.6
8.1.3 BioSFPI_GUI_RESPONSE .6
8.1.4 BioSFPI_GUI_PROGRESS_EVENT_HANDLER .6
8.2 BSFP Functions.7
8.2.1 BioSFPI_BSFPLoad.7
8.2.2 BioSFPI_UnitAttach.8
8.2.3 BioSFPI_UnitDetach.9
8.2.4 BioSFPI_QueryUnits .9
8.2.5 BioSFPI_Free .10
8.2.6 BioSFPI_ControlUnit.11
8.2.7 BioSFPI_Cancel.11
8.2.8 BioSFPI_SetPowerMode.12
8.2.9 BioSFPI_SetGUICallbacks.13
8.2.10 BioSFPI_QueryFormatInfo .13
8.2.11 BioSFPI_GetPackets .14
8.2.12 BioSFPI_DataTransfer.15
8.2.13 BioSFPI_SetIndicatorStatus.16
8.2.14 BioSFPI_GetIndicatorStatus .16
8.2.15 BioSFPI_CalibrateSensor .17
8.2.16 BioSFPI_SubscribeToGUIEvents.17
8.2.17 BioSFPI_UnsubscribeFromGUIEvents.18
Annex A (normative) Imaging biometric sensor units .20
A.1 General.20
A.1.1 Bit and Byte ordering.20
A.1.2 Scan sequence.20
A.1.3 Pixel aspect ratio.20
A.1.4 Greyscale pixel depth .20
A.1.5 Colour space.20
A.1.6 Video interlacing.21
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ISO/IEC 19784-4:2011(E)
A.2 BioSFPI_BSFPImagePropertyID. 21
A.3 BioSFPI_BSFPImagePropertySchema . 21
A.4 BioSFPI_UnitImagePropertyID. 22
A.5 BioSFPI_UnitImagePropertySchema. 22
A.6 Image sensor functions . 23
A.6.1 BioSFPI_GetImageParameters. 23
A.6.2 BioSFPI_SetImageParameters . 24
A.6.3 BioSFPI_Pause. 25
A.6.4 BioSFPI_Play. 25
Annex B (normative) Signature sensor units. 27
B.1 General. 27
B.1.1 Bit and byte ordering. 27
B.1.2 Coordinate system . 27
B.1.3 Channel inclusion field . 28
B.1.4 Sequence of sample points . 29
B.1.5 Sample Rate. 29
B.1.6 ChannelDescriptions. 29
B.2 BioSFPI_BSFPSignaturePropertyID . 29
B.3 BioSFPI_BSFPSignaturePropertySchema . 30
B.4 BioSFPI_UnitSignaturePropertyID. 30
B.5 BioSFPI_UnitSignaturePropertySchema. 31
B.6 Signature Sensor Functions. 32
B.6.1 BioSFPI_GetSignatureParameters. 32
B.6.2 BioSFPI_SetSignatureParameters . 33
Annex C (informative) Obtaining biometric sensor data across the SFPI. 35
C.1 Overall functionality . 35
C.2 Fundamentals of the data transfer interfaces. 36
C.3 Memory management. 36
C.4 Components forming the interface. 36
C.5 Implementation options for use of the data transfer interface . 36
Bibliography. 38
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ISO/IEC 19784-4:2011(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 national bodies for voting. Publication as
an International Standard requires approval by at least 75 % 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 shall not be held responsible for identifying any or all such patent rights.
ISO/IEC 19784-4 was prepared by Joint Technical Committee ISO/IEC JTC 1, Information technology,
Subcommittee SC 37, Biometrics.
ISO/IEC 19784 consists of the following parts, under the general title Information technology — Biometric
application programming interface:
⎯ Part 1: BioAPI specification
⎯ Part 2: Biometric archive function provider interface
⎯ Part 4: Biometric sensor function provider interface
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ISO/IEC 19784-4:2011(E)
Introduction
This part of ISO/IEC 19784 specifies a low-level interface that enables a Biometric Service Provider (BSP)
module (see ISO/IEC 19784-1) to interact with a biometric sensor from a different vendor [a Biometric Sensor
Function Provider (BSFP) module], using only the specification of the standardized interface. The biometric
sensor is a physical device with a small amount of associated software. The interface enables a biometric
sensor to interwork with any BSP that is designed to handle the technology supported by that sensor. It also
enables the BSP module to be independent of details of the actual sensor, although it will remain dependent
on the biometric technology it supports (finger, face, vein, etc.).
Biometric sensors can have very different working principles. Also the data formats vary very much depending
on the biometric feature and the sensor type. To cover the resulting different requirements for a generic
function provider, normative annexes contain the specific functions and data structures for typical sensor
device classes or biometric modalities. The philosophy of this part of ISO/IEC 19784 is to add such normative
annexes whenever the existing annexes do not cover the requirements for a typical sensor class.
Currently there are two normative annexes. Annex A provides type definitions and function calls designed to
support biometric sensors designed to return images (either still images or a sequence of images). Annex B
provides type definitions and function calls designed to support biometric sensors designed to return
sequences of pen movements.
The major function of a BSP module performing a capture is to produce a complete Biometric Information
Record (BIR) for returning to a biometric application (usually via a BioAPI framework).
The major function of a BSFP is to do a capture and to return data in an identified format, either as a single
piece of data (use of BioSFPI_DataTransfer) or as a series of packets (use of BioSFPI_GetPackets)
containing the captured information, or via a stream interface (see Annex C).
The BSP is responsible for turning this data into a Biometric Data Block (BDB) within a BIR for returning
across the Service Provider Interface (SPI).
Additional (minor) functions relate to control of the biometric sensor and the parameters of its operation.
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INTERNATIONAL STANDARD ISO/IEC 19784-4:2011(E)
Information technology — Biometric application programming
interface —
Part 4:
Biometric sensor function provider interface
1 Scope
This part of ISO/IEC 19784 specifies a biometric sensor interface for a Biometric Service Provider (BSP,
see ISO/IEC 19784-1). The interface supports a BSP wishing to provide the BioAPI Service Provider Interface
(SPI) functions, whilst removing device handling activity from the BSP. This part of ISO/IEC 19784 provides
an interface that can be used by all types of biometric sensor, including inter alia image streaming sensors
(infrared, face, iris, finger, etc.), voice streaming sensors and digital tablets providing dynamic signature data.
It is not in the scope of this part of ISO/IEC 19784 to define security and privacy requirements for capturing
and transferring of biometric data across the Sensor Function Provider Interface (SFPI).
2 Conformance
A BSFP shall support all the functions in Clause 8 of this part of ISO/IEC 19784 and all those in the two
normative annexes. However, those functions that have a permissible error return of
BioAPIERR_FUNCTION_NOT_SUPPORTED can always return this error. Functions that do not list this error
as an allowed return are required to perform the function as described, subject to other error returns listed.
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 19784-1, Information technology — Biometric application programming interface — Part 1: BioAPI
specification
ISO/IEC 19794-7, Information technology — Biometric data interchange formats — Part 7: Signature/sign time
series data
4 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO/IEC 19784-1 and the following apply.
NOTE Function names and data element names are not included here, but are defined within the body of this part of
ISO/IEC 19784.
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ISO/IEC 19784-4:2011(E)
4.1
Biometric Sensor Function Provider
BSFP
BioAPI component, attached to a BSP via its interface, for managing and providing information from a
biometric sensor
NOTE The biometric sensor can be a camera, a fingerprint device, an iris scanner, or a signature reader using
images, pressure, or sound, or any other type of biometric sensor.
4.2
Biometric Sensor Function Provider Interface
BSFPI
BSP-to-BSFP interface that supports the functions needed to provide biometric data and to manage the BSFP
itself and the associated device
4.3
packet
fragment of a BDB passing across the SFPI as the result of a single BioSFPI_GetPackets call
4.4
streaming data
data passing across an interface from a source that is operating continuously
5 Symbols, abbreviated terms, data structure definitions and error codes
5.1 Symbols and abbreviated terms
API – Application Programming Interface
BDB – Biometric Data Block
BFP – BioAPI Function Provider
BSP – Biometric Service Provider
BSFPI – Biometric Sensor Function Provider Interface
FPI – Function Provider Interface
ID – Identity/Identification/Identifier
SPI – Service Provider Interface
sRGB – Standard Red Green Blue (see ITU-R BT.709-5)
UUID – Universally Unique Identifier
5.2 Data structure definitions and error codes
For the purposes of this document, the data structure definitions and error codes defined in ISO/IEC 19784-1
apply.
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ISO/IEC 19784-4:2011(E)
6 Interface architecture
6.1 ISO/IEC 19784-1:2006 specifies the interface at the top of the BioAPI Framework, which a biometric
application uses to interact with BSPs, and through that to biometric sensors either directly or through BFPs
(see Figure 1 and Figure 2 of ISO/IEC 19784-1:2006).
6.2 The BSFPI contains two types of functions:
6.2.1 General BFP management functions, which are called by the BSP to manage the BFP and its
associated BioAPI Units. These functions are not directly related to SPI functions.
⎯ BioSFPI_BSFPLoad (see Clause 7)
⎯ BioSFPI_UnitAttach (called in the context of BioAPI_BSPAttach and BioSPI_BSPAttach, see Clauses 8
and 9 of ISO/IEC 19784-1:2006)
⎯ BioSFPI_UnitDetach (called in the context of BioAPI_BSPDetach and BioSPI_BSPDetach, see Clauses 8
and 9 of ISO/IEC 19784-1:2006)
⎯ BioSFPI_QueryUnits (this function is directly related to the SPI function BioSPI_QueryUnits which is
related to the API function BioAPI_QueryUnits, see Clauses 8 and 9 of ISO/IEC 19784-1:2006)
⎯ BioSFPI_Free (the relation of this function to the corresponding SPI call depends on the behaviour of the
BSP – when the BSP copies data that the BFP has allocated memory for, then it can immediately send
BioSFPI_Free to the BFP, otherwise the BSP will call this function when itself is requested to free the
memory for this data)
6.2.2 Unit management functions, which are called by the BSP to manage BioAPI Units directly. These
functions are directly related to SPI functions.
⎯ BioSFPI_ControlUnit (this function is directly related to the SPI function BioSPI_ControlUnit which is
related to the API function BioAPI_ControlUnit, see Clauses 8 and 9 of ISO/IEC 19784-1:2006)
⎯ BioSFPI_Cancel (this function can be called in relation to the corresponding calls of the SPI or the
application, but can also be called when there is no corresponding request from the BioAPI framework or
application, see Clauses 8 and 9 of ISO/IEC 19784-1:2006)
⎯ BioSFPI_SetPowerMode (this function is directly related to the SPI function BioSPI_SetPowerMode
which is related to the API function BioAPI_SetPowerMode, see Clauses 8 and 9 of
ISO/IEC 19784-1:2006)
⎯ BioSFPI_SetGUICallbacks (this function is directly related to the SPI function BioSPI_SetGUICallbacks
which is related to the API function BioAPI_SetGUICallbacks, see Clauses 8 and 9 of
ISO/IEC 19784-1:2006)
⎯ BioSFPI_SetIndicatorStatus (this function is directly related to the SPI function BioSPI_SetIndicatorStatus
which is related to the API function BioAPI_SetIndicatorStatus, see Clauses 8 and 9 of
ISO/IEC 19784-1:2006)
⎯ BioSFPI_GetIndicatorStatus (this function is directly related to the SPI function
BioSPI_GetIndicatorStatus which is related to the API function BioAPI_GetIndicatorStatus, see Clauses 8
and 9 of ISO/IEC 19784-1:2006)
⎯ BioSFPI_CalibrateSensor (this function is directly related to the SPI function BioSPI_CalibrateSensor
which is related to the API function BioAPI_CalibrateSensor, see Clauses 8 and 9 of
ISO/IEC 19784-1:2006)
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ISO/IEC 19784-4:2011(E)
The following functions are important for the interface between a BSP and an SFP, but do not map directly to
any function across the SPI between a BSP and the framework (or an application for frameworkless
operation).
⎯ BioSFPI_QueryFormatInfo (this function is not related to the SPI)
⎯ BioSFPI_ActivateSensor (this function is not related to the SPI)
⎯ BioSFPI_GetPackets (this function is not related to the SPI)
⎯ BioSFPI_DataTransfer (this function is not related to the SPI)
⎯ BioSFPI_SubscribeToGUIEvents (this function is not related to the SPI)
⎯ BioSFPI_UnsubscribeFromGUIEvents (this function is not related to the SPI)
7 Selecting and loading BFPs and BioAPI_Units
7.1 Obtaining information about BFPs and BioAPI_Units
The component registry contains information about the BioAPI framework, BSPs and BFPs (see 6.3 of
ISO/IEC 19784-1:2006).
BFP information is stored in a structure called BioAPI_BFP_SCHEMA (see 7.3 of ISO/IEC 19784-1:2006).
The BioAPI_BFP_SCHEMA contains data elements BFPPropertyID and BFPProperty. The BFPPropertyID is
a UUID identifying the type of data structure of the BFPProperty data.
Each BFP that is compliant with ISO/IEC 19784-1 and this part of ISO/IEC 19784 has to provide a
standardized BFPPropertyID and a related BFPPropertySchema. Two BSFPPropertyIDs and two related
BSFPPropertySchemas are defined in Annexes A and B. Annex A defines a BSFPPropertySchema suitable
for image devices, and Annex B defines one suitable for signature devices. These can be used in
ISO/IEC 19784-1 calls as BFPPropertyIDs and BFPPropertySchemas.
The information given in the BFPPropertySchema is stored at BFP installation time (see 6.4 of
ISO/IEC 19784-1:2006) in the component registry.
An application can obtain this information by calling BioAPI_EnumBFPs and BioAPI_QueryBFPs (see 8.1.10
and 8.1.11 of ISO/IEC 19784-1:2006).
A BSP can obtain this information by using the BioSPI_BFP_ENUMERATION_HANDLER (see 9.2.2 of
ISO/IEC 19784-1:2006).
An application can retrieve information about all BioAPI_Units supported by a particular BSP by calling the
function BioAPI_QueryUnits (see 8.1.9 of ISO/IEC 19784-1:2006). This function also works if no attach
session is established yet.
A BSP can browse the component registry for all installed BFPs by using the callback mechanism of
BioSPI_BFP_ENUMERATION_HANDLER. The BSP analyses the BFPPropertySchemas and decides which
BFPs it can support.
Note: The criteria for that decision are out of the scope of this part of ISO/IEC 19784.
During the call BioSPI_QueryUnits the BSP may load the supported BFPs. A loaded BFP automatically
detects the supported BioAPI_Units and reports the BioAPI_UNIT_SCHEMAs in the return of the
BioSFPI_QueryUnits call to the BSP, which reports them to the application.
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ISO/IEC 19784-4:2011(E)
The BSP may create a list of all BFPUuids and the UnitIDs of the supported devices for each BFP. Additional
information can be found in the parameter UnitManagerUuid of the BioAPI_UNIT_SCHEMA.
7.2 Loading BFPs
7.2.1 Loading BFPs when attaching to an unspecified BioAPI_Unit
This sub-clause describes how a BFP is loaded if the application does not choose a specific BioAPI_Unit in a
call of BioAPI_Attach. (If the application selects a specific BioAPI_Unit, see 7.2.2).
In this case the application calls the function BioAPI_BSPAttach with the value BioAPI_DONT_CARE in the
particular element of the parameter UnitList.
The BSP then performs the operation described in 7.1 using the callback mechanism of
BioSPI_BFP_ENUMERATION_HANDLER and followed by a call of BioSFPI_QueryUnits. As a result, the
BSP has a list of all units supported and their supporting BFPs. The BSP chooses one of the BioAPI_Units
and then loads the appropriate BSFP and completes the operation with a BioSFPI_BSFPLoad function call
followed by a BioSFPI_BSFPAttach function call.
Note: The criteria used to choose one of the supported BioAPI_Units are not defined in this part of ISO/IEC 19784.
7.2.2 Loading BFPs when attaching to a specific BioAPI_Unit
After issuing a BioAPI_BSPLoad, the framework will load the BSP (if supported) and issue a
BioSPI_BSPLoad.
On return, the application calls the function BioAPI_QueryUnits to determine the units supported by that BSP,
and then calls BioAPI_Attach giving the specific Unit it wishes to use. The application retrieves the
UnitSchemaArray from the BioAPI_QueryUnits and can browse this for the BioAPI_Unit information. The
application selects the UnitId it wants to attach to and calls the function BioAPI_BSPAttach. The BSP may
decide to load an appropriate BFP at this time depending on either the list being built as described at the end
of 7.1
...
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