NIST Record Types

A NIST file has up to 16 Records, each of which have fields with subfields that hold data. At each level there are different separator characters as shown below.

FILE
RECORD
Field
SubfieldUSSubfieldUS
RSFieldRS
GSRECORDGS
FS

Each file is separated by the FS "file separator" character, which is represented in

Each record is separated by the GS "Group Separator" character, which is represented in

Each Field is separated by the RS "Record Separator" character, which is represented in

Each subfield is separated by the US "Unit Separator" character, which is represented in

Each Record holds a different type of data.

1 - Transaction Information

This record contains the number of fingerprint, palmprint, facial/mugshot, or SMT images available for processing; lists all other records included in the file, and indicates the source of the physical record.

The Type-1 logical record is mandatory, must be first and alone, and is encoded in ASCII. There are eight mandatory fields and two optional fields.

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Note: each of the following logical records include an Image Designation Character (IDC), which relates items in the file contents field of the Type-1 record to each record. The IDC identifies and links logical records on the same subject matter. The IDC's value starts from zero and increments by one. Different records that deal with the same subject matter will have the same IDC - for example, a high-resolution image record of a specific fingerprint and the corresponding minutiae record for the same finger would carry the same IDC number.

2 - Descriptive Text (User-defined)

The Type-2 record is composed of user-defined textual fields providing identification and descriptive information about the subject of the fingerprint information.

The first two fields are mandatory, after which there can be up to 997 user-defined optional fields.

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3 - Fingerprint Image Data (Low-resolution grayscale)

Type-3 logical records contain low-resolution grayscale fingerprints that were subsampled, scaled down, or interpolated from higher-quality scans.

Typically, there are ten rolled impressions of the individual fingers, two plain impressions of the thumbs, and two "slaps". There can be up to 13 images in a file, each of which uses a separate Type-3 logical record.

The Type-3 record has 9 ordered, unnumbered fields, the first 8 of which contain information about the image data stored in the 9th field. All the values are stored in binary.

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4 - Fingerprint Image Data (High-resolution grayscale)

Type-4 logical records contain high-resolution grayscale fingerprints.

Typically, there are ten rolled impressions of the individual fingers, two plain impressions of the thumbs, and two "slaps".

The files, which can be compressed, are stored in binary.

The Type-4 record has 9 ordered, unnumbered fields, the first 8 of which contain information about the image data stored in the 9th field. All the values are stored in binary.

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5 - Fingerprint Image Data (Low-resolution binary)

Type-5 logical records contain low-resolution binary fingerprint image data, scanned at least at the minimum scanning resolution and then subsampled, scaled down, or interpolated.

Typically, there are ten rolled impressions of the individual fingers, two plain impressions of the thumbs, and two "slaps".

The Type-5 record has 9 ordered, unnumbered fields, the first 8 of which contain information about the image data stored in the 9th field. The values, which can be compressed, are stored in binary.

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6 - Fingerprint Image Data (High-resolution binary)

Type-6 logical records contain high-resolution binary fingerprints.

Typically, there are ten rolled impressions of the individual fingers, two plain impressions of the thumbs, and two "slaps".

The Type-6 record has 9 ordered, unnumbered fields, the first 8 of which contain information about the image data stored in the 9th field. The values, which can be compressed, are stored in binary.

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7 - Image Data (User-defined)

Type-7 logical records contain user-defined image data that is not elsewhere specified or described.

This record type handles miscellaneous images such as wrists, toes, soles, etc. It does not store any ASCII data - use a type-16 record for data that needs to be tagged with text. With the exception of the length and IDC fields, the format, parameters, and types of images to be exchanged are undefined and will be agreed upon between the sender and recipient.

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8 - Signature Image Data

Type-8 logical records contain scanned high-resolution binary or vectored images representing the signature of the person being fingerprinted or of the official taking the fingerprint.

If scanned, the resolution of the image data must be at least the minimum scanning resolution. If the resolution exceeds the bounds of the transmitting resolutions, then the scanned image will need to be subsampled, scaled down, or interpolated. If vectored, the signature data is expressed as a series of binary numbers.

Typically, there may be up to two of these Type-8 signature records in a file - the subject, the official processing the subject, or both.

When there are one or two Type-8 logical records, each record has 8 unnumbered, ordered fields. The first 7 fields total twelve bytes and provide information about the image stored in the 8th field. The size of field eight is determined from the LEN field of the record itself.

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9 - Minutiae Data

Type-9 logical records contain geometric and topological minutiae information encoded from a fingerprint, palm, or latent image.

Each record represents the processed image data from which the location and orientation descriptors of extracted minutiae characteristics are listed. The primary use of this record type shall be for remote searching of latent prints.

For a tenprint search transaction, there may be up to ten Type-9 records in a file, each for a different finger. There may be up to six of these records for palmprint searches.

The first twelve ASCII fields of the Type-9 logical record encode minutiae using a generic encoding method detailed in the Minutia Type Information specification. using a variety of methods, so that AFIS vendors can customize the encoding of minutiae by reserving a block of uniquely numbered fields. All implementations must contain the first four fields described below, but Field-5 through Field-12 are vendor-dependent and not required.

10 Facial & SMT Image Data

Type-10 records contain mugshots, photographs, and textual information about the subject.

The source of the image data can be from scanning a photograph, an image captured with a digital camera, or a digitized "freeze-frame" from a video camera.

A Type-10 logical record has numbered fields, the first two of which are ordered and mandatory. The last field in the record should contain the image.

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11 - Reserved for Future Use

12 - Reserved for Future Use

13 - Latent Image Data (Variable-resolution)

Type-13 tagged-field image records contain variable-resolution latent fingerprint and palmprint image data together with fixed and user-defined textual information.

It is strongly recommended that the minimum scanning resolution (or effective scanning resolution) and transmission rate for latent images be 39.38 ppmm plus or minus 0.40 ppmm (1000 ppi plus or minus 10 ppi). However, in all cases the scanning resolution used to capture a latent image shall be at least as great as the minimum scanning resolution of 19.69 ppmm (500 ppi).

The variable-resolution latent image data contained in the Type-13 logical record must be uncompressed or may be the output from a lossless compression algorithm. There is no limit on the number of these latent records that may be present in a transaction.

14 - Tenprint fingerprint Impressions (Variable-resolution)

Type-14 tagged-field image records contain variable-resolution tenprint fingerprint image data together with fixed and user-defined textual information fields.

Fingerprint images can be either rolled or plain impressions. The scanning resolution is not specified for this record type. While the Type-14 record may be used for the exchange of 19.69 ppmm (500 ppi) images, it is strongly recommended that the minimum scanning resolution (or effective scanning resolution) for tenprint images be 39.38 ppmm plus or minus 0.40 ppmm (1000 ppi plus or minus 10 ppi). It should be noted that as the resolution is increased, more detailed ridge and structure information becomes available in the image. However, in all cases the scanning resolution used to capture a tenprint image shall be at least as great as the minimum scanning resolution of 19.69 ppmm (500ppi).

The variable-resolution tenprint image data contained in the Type-14 logical record may be in a compressed form. Typically, there may be up to 14 of these Type-14 records in a file; ten rolled impressions of the individual fingers, two plain impressions of the thumbs and two plain impressions of the four simultaneously obtained remaining fingers of each hand.

15 - Palmprint Image Data (Variable-resolution)

Type-15 tagged-field image records contain variable-resolution palmprint image data together with fixed and user-defined textual information fields.

Image data contained in this record may be the full palm impression, the upper half of the palm, the lower half of the palm, or the writer's palmprint impression. The scanning resolution is not specified for this record type. While the Type-15 record may be used for the exchange of 19.69 ppmm (500 ppi) images, it is strongly recommended that the minimum scanning resolution (or effective scanning resolution) for palmprint images be 39.38 ppmm plus or minus 0.40 ppmm (1000 ppi plus or minus 10 ppi). It should be noted that as the resolution is increased, more detailed ridge and structure information becomes available in the image. However, in all cases the scanning resolution used to capture a tenprint image shall be at least as great as the minimum scanning resolution of 19.69 ppmm (500ppi).

The variable-resolution palmprint image data contained in the Type-15 logical record may be in a compressed form. Typically, there may be up to 6 of these Type-15 records in a file; two full palmprints or four partial palms, and two writer?s palms.

16 - User-defined Testing Image Data (Variable-resolution)

The Type-16 record, a tagged-field version of the Type-7 record, contains miscellaneous images not elsewhere specified or described, together with textual information fields. It is designed for development and testing.

The scanning resolution is not specified for this record type but must be at least as great as the minimum scanning resolution (19.69 ppmm, or 500ppi). Increases in the resolution used for capturing images should follow the recommended migration path to 39.38 ppmm (1000 ppi), 78.76 ppmm (2000 ppi), etc. It should be noted that as the resolution is increased, more detailed ridge and structure information becomes available in the image.

The variable-resolution image data contained in the Type-16 logical record may be in a compressed form.

With the exception of the first two tagged fields and the descriptors for the image data, the remaining details of the Type-16 record are undefined by this standard and will be agreed upon between the sender and recipient.