List of ISO validations performed by CTK
Last updated
Last updated
Copyright © 2021 MOSIP. This work is licensed under a Creative Commons Attribution (CC-BY-4.0) International License unless otherwise noted.
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.
Refer ISO 19794-4:2011 Specifications.
| Sl.No | Name | Type | Description | Length | Valid values | Is this attribute mandatory? | Image verification |
|---|---|---|---|---|---|---|---|
Refer ISO 19794-6:2011 Specifications.
Refer ISO 19794-6:2011 Specifications.
| Sl.No | Name | Type | Description | Length | Valid values | Is this attribute mandatory? | Image verification |
|---|---|---|---|---|---|---|---|
| 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
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
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