M1- Finger Minutiae/Image Harmonization

 

Minutiae Placement and Type 

For minutiae encoding compliant with ANSI INCITS 378-2004, determination of 

the placement (location and angular direction) of individual minutiae shall be 

determined according to section 5 of ANSI INCITS 378-2004. 

Coordinate System 

The coordinate system used to express the minutiae of a fingerprint shall be a 

Cartesian coordinate system. Minutiae locations shall be represented by their x 

and y coordinates. The origin of the coordinate system shall be the upper left 

corner of the original image with x increasing to the right and y increasing 

downward. Both x and y coordinates of a minutiae shall be represented in pixel 

units from the origin. It should be noted that the location of the origin and units 

of measure is not in agreement with the convention used in Section 16.1.4. 

Minutiae Direction 

Angles are expressed in standard mathematical format, with zero degrees to the 

right and angles increasing in the counterclockwise direction. Recorded angles are 

in the direction pointing back along the ridge for a ridge ending and toward the 

center of the valley for a bifurcation. This convention is 180 degrees opposite of 

the angle convention described in Section 16.1.4. 

M1 Minutiae Fields for the Type 9 logical record

Fields 9.001- 9.004 

These first four fields are mandatory and retain the same meaning a described in 

Sections 16.2.1 through 16.2.4. 

Field 9.121. CBEFF Information 

This mandatory field shall contain three information items. The first information 

item shall contain the value "27" (0x1B). This is the identification of the CBEFF 

Format Owner assigned by the International Biometric Industry Association 

(IBIA) to INCITS Technical Committee M1. The <US> character shall delimit 

this item from the CBEFF Format Type that is assigned a value of "513" (0x0201) 

to indicate that this record contains only location and angular direction data 

without any Extended Data Block information. The <US> character shall delimit 
this item from the CBEFF Product Identifier (PID) that identifies the "owner" of 

the encoding equipment. The vendor establishes this value. It can be obtained 

from the IBIA website (www.ibia.org) if it is posted. 

Field 9.122. Capture Equipment Identification 

This mandatory field shall contain two information items separated by the <US> 

character. The first shall contain "APPF" if the equipment used originally to 

acquire the image was certified to comply with Appendix F (IAFIS Image Quality 

Specification, January 29, 1999) of CJIS-RS-0010, the Federal Bureau of 

Investigation's Electronic Fingerprint Transmission Specification. If the 

equipment did not comply it will contain the value of "NONE". The second 

information item shall contain the Capture Equipment ID which is a vendorassigned product number of the capture equipment. A value of "0" indicates that 

the capture equipment ID is unreported. 

Field 9.123. Size of Scanned Image 

This mandatory field shall contains the size of the original image. Two 

information items separated by the <US> character list the number of pixels in the 

in the x (horizontal) and y (vertical) directions of the original image. Each value 

is limited to 65,534 pixels. 

Field 9.124. Scanning Resolution 

This mandatory field shall contains the x (horizontal) and y (vertical) resolutions 

used for scanning the original image. Two information items separated by the 

<US> character list the original scanning resolution in the x (horizontal) and y 

(vertical) directions. Each value is limited to 65,534 pixels. 

Field 9.125. Finger View 

This mandatory field contains the view number of the finger associated with this 

record's data. The view number begins with "0" and increments by one to "15". 

Field 9.126. Finger Position (FGP) 

This mandatory field shall contain the code designating the finger position that 

produced the information in this Type-9 record. A code between 1 and 10 taken 

from table 6 shall be used to indicate the finger position. 

Field 9.127. Finger Quality

The mandatory field shall contain the quality of the overall finger minutiae data 

and shall be between 0 and 100. This number is an overall expression of the 

quality of the finger record, and represents quality of the original image, of the 
minutia extraction and any additional operations that may affect the minutiae 

record. 

Field 9.128. Number of Minutiae

The mandatory field shall contain a count of the number of minutiae recorded in 

this logical record. 

Field 9.129. Finger Minutiae Data 

The mandatory field has five information items separated by the <US> character. 

It consists of several subfields, each containing the details for a single minutiae. 

The total number of minutiae subfields must agree with the count found in field 

128. The first and second information items are the 'x' coordinate and 'y' 

coordinates of the minutiae. The third information item is the minutiae angle 

recorded in units of two degrees. This value shall be nonnegative between 0 and 

179. The fourth information item is the minutiae type. A value of "0" is used to 

represent a minutiae of type "OTHER", a value of "1" for a ridge ending and a 

value of "2" for a ridge bifurcation. The final information item represents the 

quality of each minutiae. This value shall range from 1 as a minimum to 100 as a 

maximum. A value of "0" indicates that no quality value is available. Each 

subfield shall be separated from the next with the use of the <RS> separator 

character. 

Additional M1-Based Fields for Type 14 Records

Field 14.025. Size of Scanned Image 

This mandatory field shall contain the size of the original image. Two 

information items separated by the <US> character list the number of pixels in the 

in the x (horizontal) and y (vertical) directions of the original image. Each value 

is limited to 65,534 pixels. 

Field 14.026. Scanning Resolution 

This mandatory field shall contains the x (horizontal) and y (vertical) resolutions 

used for scanning the original image. Two information items separated by the 

<US> character list the original scanning resolution in the x (horizontal) and y 

(vertical) directions. Each value is limited to 65,534 pixels. 

Field 14.027. Finger View 

This mandatory field contains the view number of the finger associated with this 

record's data. The view number begins with "0" and increments by one to "15". 
Image Quality Score

14.024 Image Quality Score (IQS) 

This ASCII field shall specify the quality score data for the finger image(s) stored in this record. 

Each subfield shall contain five information items to identify the finger number, a quality score, 

and the algorithm used to create the quality score. This information is useful to enable the 

recipient of the quality score to differentiate between quality scores generated by different 

algorithms and adjust for any differences in processing or analysis as necessary. 

The first information item is the finger number as chosen from Table 6 or 19. The second 

information item is a quantitative expression of the predicted matching performance of the 

biometric sample. This item contains the ASCII representation of a quality algorithm's score 

mapped to an integer image quality value between 1 and 100. Higher values indicate better 

quality. An entry of “-1” shall indicate a failed attempt to calculate a quality score. The third 

information item shall specify the alphanumeric ID value of the vendor of the quality algorithm 

used to calculate the quality score. NIST will maintain a Vendor Registry that will map the 

values in this field to registered quality algorithm vendors. The Vendor ID shall be composed of 

ASCII printable characters up to 16 characters in length. The fourth information item shall 

specify a numeric product code assigned by the vendor of the quality algorithm. It indicates 

which of the vendor’s algorithms was used in the calculation of the quality score. This field 

contains the ASCII representation of the integer product code and should be within the range 1 to 

65535. The final information item shall specify the version number of the quality algorithm used. 

The version number shall include a major number and minor number separated by a period. The 

major number and minor numbers should each be the ASCII representation of integer values in 

the range 0 to 255. 

Each of the five information items shall be separated from the next by the <US> separator 

character. For the case of segmented slap images (Type 13-15), the subfield is repeated for each 

segmented finger image with the <RS> character separating the sets of finger image quality 

information items. For the case where more than one quality algorithm is used to evaluate the 

quality of the same finger, the subfield is repeated for each algorithm using the <RS> characters 

as the separator between quality algorithms. For the case where more than one quality algorithm 

is applied to a segmented slap image, the set of quality information items for each finger shall be 

listed for all fingers evaluated by the first algorithm, then for all fingers evaluated by the second 

algorithm, and so forth. 

An example transaction for a quality score of 100 generated for the right index finger using a 

quality algorithm with a product code of 64530, version 001.123, by a vendor with a Vendor ID 

of “NIST” is: 

“10.024:2 US 100 USNIST US64530 US001.123 GS”. 
Segmented Finger Quality

14.023 Segmented Finger Quality (SFQ) 

This ASCII field shall be present if the captured image was the plain right or left four fingers or 

the combination of the left and right thumbs. It specifies the quality score data assigned by a 

finger image segmentation algorithm that is used to locate the individual fingers within a plain 

image. It provides a measure of estimated correctness regarding the accuracy of the location of 

the segmented finger within an image. For each segmented finger, this field shall contain five 

information items to identify the finger number, a quality score, and the algorithm used to create 

the quality score. This information is useful to enable the recipient of this segmentation score to 

differentiate between segmentation scores generated by different segmentation algorithms and 

adjust for any differences in processing or analysis as necessary. 

The first information item is the finger number between one and ten as chosen from Table 6. The 

second information item is a quantitative prediction of the correctness of the determined offsets to 

a specific finger image. It contains the ASCII representation of the algorithm's score mapped to 

an integer image quality value between 1 and 100. Higher values indicate better quality. An 

entry of “-1” shall indicate a failed attempt to calculate a score. The third information item shall 

specify the alphanumeric ID value of the vendor of the segmentation algorithm. NIST will 

maintain a Vendor Registry that will map the values in this field to registered quality algorithm 

vendors. The Vendor ID shall be composed of ASCII printable characters up to 16 characters in 

length. The fourth information item shall specify a numeric product code assigned by the vendor 

of the quality algorithm. It indicates which of the vendor’s algorithms was used in the calculation 

of the quality score. This field contains the ASCII representation of the integer product code and 

should be within the range 1 to 65535. The final information item shall specify the version 

number of the quality algorithm used. The version number shall include a major number and 

minor number separated by a period. The major number and minor numbers should each be the 

ASCII representation of integer values in the range 0 to 255. 

Each of the five information items shall be separated from the next by the <US> separator 

character. This subfield is repeated for each segmented finger whose coordinates appear in field 

14.021. The <RS> character separates each set of five information items. For the case where 

more than one segmentation algorithm is applied to a multi-finger plain image, the set of 

segmentation information items for each finger shall be ordered corresponding to the entries in 

field 14.021. 

An example transaction for a quality score of 75 generated for each of the right four plain fingers 

using a segmentation algorithm with a product code of 64420, version 002.013, by a vendor with 

a Vendor ID of “NIST” is: 

 “10.023:2US75USNISTUS64420US002.013RS3US75USNISTUS64420US002.013RS4US75USNIST

US64420 US002.013 RS5US75USNIST US64420 US002.013 GS"