List of ISO validations performed by CTK

  • SBI captures biometrics by receiving raw data from biometric devices, processing and converting it into standardized templates, and securely storing them for identification and verification purposes.

  • In CTK, validations are performed on these biometrics to check if they follow the defined ISO standards.

  • ISO – International Organization for Standardization refers to an international standard development organization that develops standards to ensure the safety, quality and effectiveness of products and services.

  • In CTK, ISO validations are performed in three modalities- Finger, Face and Iris.

  • There are two types of ISO validations.

    • General Header

    • Representation Header

  • There are many validations for each type. The tables below contain a list of these validations.

  • ISOStandardsValidator is a validator that has been developed for CTK. All the validations mentioned above have been done in this validator.

  • A total of 8 test cases (SBI1062 to SBI1069) have been added to CTK for ISO validation.

The figure below represents the testcase result of ISO validation.

The list of validations performed for each of the modalities is given below.

Finger

Refer ISO 19794-4:2011 Specifications.

Sl.No
Name
Type
Description
Length
Valid values
Is this attribute mandatory?
Image verification

1.

Format Identifier

General Header

FIR – Finger Image Record

4 bytes

464952Hex (F I R 00Hex)

yes

2.

Version number

General Header

020 in ASCII

4 bytes

30323000Hex (0 2 0 00Hex)

yes

3.

Length of record

General Header

Includes all finger/palm representations, quality blocks and certification blocks1

4 bytes

57 to (232-1)

yes

4.

Number of Finger/Palm representations

General Header

[ (14 finger positions) + (11 multiple finger positions) + (17 palm codes) ]* 16 = 672 possible representations

2 bytes

1 to 672

yes

5.

Certification flag

General Header

Indicates the presence of any device certification blocks within the representation headers

1 byte

0, 1

yes

6.

No of Distinct finger/Palm Position

General Header

Number of fingers or palms represented

1 byte

>=1

yes

7.

Representation Length

Representation Header

The representation-length field denotes the length in bytes of the representation including the representation header field.

4 bytes

yes

8.

Capture date and time

Representation Header

The capture date and time field shall indicate when the capture of this representation started in Coordinated Universal Time (UTC). The capture date and time field shall consist of 9 bytes. Its value shall be encoded in the form given in ISO/IEC 19794-1.

9 bytes

yes

9.

No of Quality block

Representation Header

1 byte

10.

Quality block

Representation Header

5x

Quality Score 1 byte Quality algorithm vendorIdentifier 2 bytes Quality algorithm Identifier 2 bytes

no

11.

No of Certification Blocks

Representation Header

1 byte

yes

12.

Finger/Palm Position

Representation Header

Unknown 0 Right thumb 1 Right index finger 2 Right middle finger 3 Right ring finger 4 Right little finger 5 Left thumb 6 Left index finger 7 Left middle finger 8 Left ring finger 9 Left little finger 10

1 byte

yes

13.

Representation No

Representation Header

1 byte

yes

14.

Image Data Length

Representation Header

Number of bytes for the compressed/uncompressed image data

4 bytes

0 to (232-58)

yes

15.

Image Data

Representation Header

yes

yes

Face

Refer ISO 19794-6:2011 Specifications.

Sl.No
Name
Type
Description
Length
Valid values
Is this attribute mandatory?
Image verification

1.

Format Identifier

General Header

Indicates Face representation data

4 bytes

46414300HEX (F A C 0HEX)

yes

2.

Version number

General Header

030 in ASCII

4 bytes

30333000HEX (0 3 0 00HEX)

yes

3.

Length of record

General Header

Includes Face Record Header and Facial Record Data. The minimum of 68 bytes includes the smallest JPEG image

4 bytes

68 ≤ Length of Record ≤ 232 - 1

yes

4.

Number of iris representations

General Header

The total number of iris representations in this record. This shall be recorded in two bytes. A minimum of one representation is required.

2 bytes

1 ... 65,535

yes

5.

Certification flag

General Header

No certification schemes are available for this part of ISO/IEC 19794

1 byte

00HEX

yes

6.

Temperol Sematics

General Header

One representation is present

2 bytes

0000HEX

yes

7.

Representation Length

Representation Header

The representation-length field denotes the length in bytes of the representation including the representation header field.

4 bytes

yes

8.

Capture date and time

Representation Header

The capture date and time field shall indicate when the capture of this representation started in Coordinated Universal Time (UTC). The capture date and time field shall consist of 9 bytes. Its value shall be encoded in the form given in ISO/IEC 19794-1.

9 bytes

yes

9.

No of Quality block

Representation Header

1 byte

10.

Quality block

Representation Header

5x

Quality Score 1 byte Quality algorithm vendor Identifier 2 bytes Quality algorithm Identifier 2 bytes

no

11.

Face Image Type

Image Information

01HEX Full Frontal

1 byte

no

12.

Image Data Type

Image Information

01HEX JPEG 2000 (lossy)[AUTH] 02HEX JPEG 2000 (lossless) [REG]

1 byte

yes

yes

13.

Width

Image Information

2 bytes

yes

yes

14.

Height

Image Information

2 bytes

yes

yes

15.

Image Colour Space

Image Information

1 byte

yes

yes

16.

Image Data Length

Image Information

4 bytes

1 to 4 294 967 226

yes

17.

Image Data

Image Information

yes

yes

Iris

Refer ISO 19794-6:2011 Specifications.

Sl.No
Name
Type
Description
Length
Valid values
Is this attribute mandatory?
Image verification

1.

Format Identifier

General Header

The format identifier shall be recorded in four bytes. The format identifier shall consist of three characters IIR, standing for iris image record, followed by a zero byte as a NULL string terminator.

4 bytes

49495200Hex (I I R 00Hex)

yes

2.

Version number

General Header

This number indicates the second version of this part of ISO/IEC 19794 used for constructing the iris image data record and shall be placed in four bytes. This version number shall consist of three ASCII numerals followed by a zero byte as a NULL string terminator

4 bytes

30323000Hex (0 2 0 00Hex)

yes

3.

Length of record

General Header

The length (in bytes) of the entire iris image data record shall be recorded in four bytes. This count shall be the total length of the data block including the iris general header and one or more representation records.

4 bytes

69 to (232-1)

yes

4.

Number of iris representations

General Header

The total number of iris representations in this record. This shall be recorded in two bytes. A minimum of one representation is required.

2 bytes

1 ... 65,535

yes

5.

Certification flag

General Header

No certification schemes are available for this part of ISO/IEC 19794

1 byte

00Hex

yes

6.

Representation Length

Representation Header

The representation-length field denotes the length in bytes of the representation including the representation header field.

4 bytes

yes

7.

Capture date and time

Representation Header

The capture date and time field shall indicate when the capture of this representation started in Coordinated Universal Time (UTC). The capture date and time field shall consist of 9 bytes. Its value shall be encoded in the form given in ISO/IEC 19794-1.

9 bytes

yes

8.

Quality block

Representation Header

A quality record shall consist of a length field followed by zero or more quality blocks. The length field shall consist of one byte. It shall represent the number of quality blocks as an unsigned integer. Each quality block shall consist of – a quality score, – a quality algorithm vendor identifier, and – a quality algorithm identifier. A quality score should express the predicted comparison performance of a representation. A quality score shall be encoded in one byte as an unsigned integer. Allowed values are – 0 to 100 with higher values indicating better quality, – IMAGE_QUAL_FAILED = 255 (FFHex), indicating that an attempt to calculate a quality score failed. The quality algorithm vendor identifier shall identify the provider of the quality algorithm. The quality algorithm vendor identifier shall be encoded in two bytes carrying a CBEFF biometric organization identifier (registered by IBIA or other approved registration authority). A value of all zeros shall indicate that the quality algorithm vendor is unreported. The quality algorithm identifier shall identify the vendor’s quality algorithm that created the quality score. It shall be assigned by the provider of the quality algorithm or an approved registration authority. The quality algorithm identifier shall be encoded in two bytes. A value of all zeros shall indicate that the quality algorithm is unreported.

1 to n bytes

yes

9.

Representation number

RepresentationHeader

Representation sequence number

2 Bytes

yes

10.

Eye label

Representation Header

These refer to the subject's own eyes.

1 byte

yes

11.

Image type

Representation Header

An uncropped rectilinear iris image. A rectilinear iris image in VGA (640x480) format. A cropped, centred, iris image with (0,6R 0,2R) margins. A cropped and region-of-interest masked, centred, iris image with (0,6R 0,2R) margins

1 byte

IMAGE_TYPE_UNCROPPED = 1 (01Hex) IMAGE_TYPE_VGA = 2 (02Hex) IMAGE_TYPE_CROPPED = 3 (03Hex) MAGE_TYPE_CROPPED_AND_MASKED = 7 (07Hex)

yes

12.

Image format

Representation Header

Format of image data

1 byte

IMAGEFORMAT_MONO_RAW = 2 (02Hex) IMAGEFORMAT_MONO_JPEG2000 = 10 (0AHex) IMAGEFORMAT_MONO_PNG = 14 (0EHex)

yes

yes

13.

Image width

Representation Header

Width in pixels

2 bytes

> 0

yes

yes

14.

Image height

Representation Header

Height in pixels

2 bytes

> 0

yes

yes

15.

Bit depth

Representation Header

Bit depth in bits per pixel. (Images having > 8 bpp shall be encoded using PNG or JPEG2000.)

1 byte

At least 8

yes

yes

16.

Image Data Length

Representation Header

Size of the image data (Representation body), in bytes

4 bytes

1 to 4 294 967 226

yes

17.

Image Data

Representation Header

yes

yes

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