National Imagery Transmission Format: format specification

The NITF (National Image Transition Format) format is a file format developed by the U.S. Government for storing imagery, e.g. from satellites.

According to the foreword of the specification:

The National Imagery Transmission Format Standard (NITFS) is the suite of standards for formatting digital imagery and imagery-related products and exchanging them among members of the Intelligence Community (IC) as defined by the Executive Order 12333, and other United States Government departments and agencies."

This implementation is set to version format (file_version) of 02.10 and standard_type of BF01. It was implemented by River Loop Security.

File extension

["ntf", "nitf", "ntf.r0", "ntf.r1", "ntf.r2", "ntf.r3", "ntf.r4", "ntf.r5"]

KS implementation details

License: MIT
Minimal Kaitai Struct required: 0.8

This page hosts a formal specification of National Imagery Transmission Format using Kaitai Struct. This specification can be automatically translated into a variety of programming languages to get a parsing library.

Block diagram

Format specification in Kaitai Struct YAML

meta:
  id: nitf
  title: National Imagery Transmission Format
  file-extension:
    - ntf
    - nitf
    - ntf.r0
    - ntf.r1
    - ntf.r2
    - ntf.r3
    - ntf.r4
    - ntf.r5
  ks-version: 0.8
  encoding: UTF-8
  endian: be
  license: MIT
doc: |
  The NITF (National Image Transition Format) format is a file format developed by the U.S. Government for
  storing imagery, e.g. from satellites.

  According to the [foreword of the specification](https://gwg.nga.mil/ntb/baseline/docs/2500c/2500C.pdf):
  > The National Imagery Transmission Format Standard (NITFS) is the suite of standards for formatting digital
  > imagery and imagery-related products and exchanging them among members of the Intelligence Community (IC) as
  > defined by the Executive Order 12333, and other United States Government departments and agencies."

  This implementation is set to version format (`file_version`) of 02.10 and `standard_type` of `BF01`.
  It was implemented by [River Loop Security](https://riverloopsecurity.com).
doc-ref: https://gwg.nga.mil/ntb/baseline/docs/2500c/2500C.pdf
seq:
  - id: header
    type: header
  - id: image_segments
    type: image_segment(_index)
    repeat: expr
    repeat-expr: header.num_image_segments.to_i 
  - id: graphics_segments
    type: graphics_segment(_index)
    repeat: expr
    repeat-expr: header.num_graphics_segments.to_i
  - id: text_segments
    type: text_segment(_index)
    repeat: expr
    repeat-expr: header.num_text_files.to_i
  - id: data_extension_segments
    type: data_extension_segment(_index)
    repeat: expr
    repeat-expr: header.num_data_extension.to_i
  - id: reserved_extension_segments
    type: reserved_extension_segment(_index)
    repeat: expr
    repeat-expr: header.num_reserved_extension.to_i
types:
  header:
    seq:
      - id: file_profile_name
        -orig-id: fhdr
        contents: 'NITF'
      - id: file_version
        -orig-id: fver
        contents: '02.10'
      - id: complexity_level
        -orig-id: clevel
        size: 2
      - id: standard_type
        -orig-id: stype
        contents: 'BF01'
        doc: 'Value of BF01 indicates the file is formatted using ISO/IEC IS 12087-5.'
      - id: originating_station_id
        -orig-id: ostaid
        type: str
        size: 10
      - id: file_date_time
        -orig-id: fdt
        type: date_time
      - id: file_title
        -orig-id: ftitle
        type: str
        size: 80
      - id: file_security
        -orig-id: fclasnfo
        type: clasnfo
      - id: file_copy_number
        -orig-id: fscop
        type: str
        size: 5
      - id: file_num_of_copys
        -orig-id: fscpys
        type: str
        size: 5
      - id: encryption
        -orig-id: encryp
        type: encrypt
      - id: file_bg_color
        -orig-id: fbkgc
        size: 3
      - id: originator_name
        -orig-id: oname
        type: str
        size: 24
      - id: originator_phone
        -orig-id: ophone
        type: str
        size: 18
      - id: file_length
        -orig-id: fl
        type: str
        size: 12
      - id: file_header_length
        -orig-id: hl
        type: str
        size: 6
      - id: num_image_segments
        -orig-id: numi
        type: str
        size: 3
      - id: linfo
        type: length_image_info
        repeat: expr
        repeat-expr: num_image_segments.to_i
      - id: num_graphics_segments
        -orig-id: nums
        type: str
        size: 3
      - id: lnnfo
        type: length_graphic_info
        repeat: expr
        repeat-expr: num_graphics_segments.to_i
      - id: reserved_numx
        -orig-id: numx
        type: str
        size: 3
      - id: num_text_files
        -orig-id: numt
        type: str
        size: 3
      - id: ltnfo
        type: length_text_info
        repeat: expr
        repeat-expr: num_text_files.to_i
      - id: num_data_extension
        -orig-id: numdes
        type: str
        size: 3
      - id: ldnfo
        type: length_data_info
        repeat: expr
        repeat-expr: num_data_extension.to_i
      - id: num_reserved_extension
        -orig-id: numres
        type: str
        size: 3
      - id: lrnfo
        type: length_reserved_info
        repeat: expr
        repeat-expr: num_reserved_extension.to_i
      - id: user_defined_header
        type: tre_header
      - id: extended_header
        type: tre_header
  date_time:
    seq:
      - type: str
        size: 14
        doc: 'UTC time of image acquisition in the format CCYYMMDDhhmmss: CC century, YY last two digits of the year, MM month, DD day, hh hour, mm minute, ss second'
  encrypt:
    seq:
      - type: str
        size: 1
  clasnfo:
    seq:
      - id: security_class
        -orig-id: sclas
        type: str
        size: 1
      - id: security_system
        -orig-id: sclsy
        type: str
        size: 2
      - id: codewords
        -orig-id: scode
        type: str
        size: 11
      - id: control_and_handling
        -orig-id: sctlh
        type: str
        size: 2
      - id: releaseability
        -orig-id: srel
        type: str
        size: 20
      - id: declass_type
        -orig-id: sdctp
        type: str
        size: 2
      - id: declass_date
        -orig-id: sdcdt
        type: str
        size: 8
      - id: declass_exemption
        -orig-id: sdcxm
        type: str
        size: 4
      - id: downgrade
        -orig-id: sdg
        type: str
        size: 1
      - id: downgrade_date
        -orig-id: sdgdt
        type: str
        size: 8
      - id: class_text
        -orig-id: scltx
        type: str
        size: 43
      - id: class_authority_type
        -orig-id: scatp
        type: str
        size: 1
      - id: class_authority
        -orig-id: scaut
        type: str
        size: 40
      - id: class_reason
        -orig-id: scrsn
        type: str
        size: 1
      - id: source_date
        -orig-id: ssrdt
        type: str
        size: 8
      - id: control_number
        -orig-id: sctln
        type: str
        size: 15
  length_image_info:
    seq:
      - id: length_image_subheader
        -orig-id: lish
        type: str
        size: 6
      - id: length_image_segment
        -orig-id: li
        type: str
        size: 10
  length_graphic_info:
    seq:
      - id: length_graphic_subheader
        -orig-id: lssh
        type: str
        size: 4
      - id: length_graphic_segment
        -orig-id: ls
        type: str
        size: 6
  length_text_info:
    seq:
      - id: length_text_subheader
        -orig-id: ltsh
        type: str
        size: 4
      - id: length_text_segment
        -orig-id: lt
        type: str
        size: 5
  length_data_info:
    seq:
      - id: length_data_extension_subheader
        -orig-id: ldsh
        type: str
        size: 4
      - id: length_data_extension_segment
        -orig-id: ld
        type: str
        size: 9
  length_reserved_info:
    seq:
      - id: length_reserved_extension_subheader
        -orig-id: lresh
        type: str
        size: 4
      - id: length_reserved_extension_segment
        -orig-id: lre
        type: str
        size: 7
  image_segment:
    params:
      - id: idx
        type: u2
    instances:
      has_mask:
        value: image_sub_header.img_compression.substring(0, 1) == 'M' or image_sub_header.img_compression.substring(1, 2) == 'M'
    seq:
      - id: image_sub_header
        type: image_sub_header
      - id: image_data_mask
        type: image_data_mask
        if: has_mask
      - id: image_data_field
        if: has_mask
        size: _parent.header.linfo[idx].length_image_segment.to_i - image_data_mask.total_size
  image_sub_header:
    seq:
      - id: file_part_type
        -orig-id: im
        contents: 'IM'
      - id: image_id_1
        -orig-id: iid1
        type: str
        size: 10
      - id: image_date_time
        -orig-id: idatim
        type: date_time
      - id: target_id
        -orig-id: tgtid
        type: str
        size: 17
      - id: image_id_2
        -orig-id: iid2
        type: str
        size: 80
      - id: image_security_classification
        -orig-id: iclasnfo
        type: clasnfo
      - id: encryption
        -orig-id: encryp
        type: encrypt
      - id: image_source
        -orig-id: isorce
        type: str
        size: 42
      - id: num_sig_rows
        -orig-id: nrows
        type: str
        size: 8
        doc: 'Total number of rows of significant pixels in the image; only rows indexed 0 to (NROWS - 1) of the image contain significant data.'
      - id: num_sig_cols
        -orig-id: ncols
        type: str
        size: 8
      - id: pixel_value_type
        -orig-id: pvtype
        type: str
        size: 3
      - id: image_representation
        -orig-id: irep
        type: str
        size: 8
        doc: 'MONO, RGB, RGB/LUT, MULTI, NODISPLY, NVECTOR, POLAR, VPH, YCbCr601'
      - id: image_category
        -orig-id: icat
        type: str
        size: 8
        doc: 'VIS, SL, TI, FL, RD, EO, OP, HR, HS,CP, BP, SAR, SARIQ, IR, MAP, MS, FP, MRI, XRAY, CAT, VD, PAT, LEG, DTEM, MATR, LOCG, BARO, CURRENT, DEPTH, WIND'
      - id: actual_bits_per_pixel_per_band
        -orig-id: abpp
        type: str
        size: 2
      - id: pixel_justification
        -orig-id: pjust
        type: str
        size: 1
      - id: image_coordinate_rep
        -orig-id: icords
        type: str
        size: 1
      - id: image_geo_loc
        -orig-id: igeolo
        type: str
        size: 60
      - id: num_img_comments
        -orig-id: nicom
        type: str
        size: 1
      - id: img_comments
        -orig-id: icom
        type: image_comment
        repeat: expr
        repeat-expr: num_img_comments.to_i
      - id: img_compression
        -orig-id: ic
        type: str
        size: 2
      - id: compression_rate_code
        -orig-id: comrat
        type: str
        size: 4
      - id: num_bands
        -orig-id: nbands
        type: str
        size: 1
      - id: num_multispectral_bands
        -orig-id: xbands
        type: str
        size: 5
        if: num_bands.to_i == 0
      - id: bands
        type: band_info
        repeat: expr
        repeat-expr: "num_bands.to_i != 0 ? num_bands.to_i : num_multispectral_bands.to_i"
      - id: img_sync_code
        -orig-id: isync
        type: str
        size: 1
        doc: 'Reserved for future use.'
      - id: img_mode
        -orig-id: imode
        type: str
        size: 1
        doc: 'B = Band Interleaved by Block, P = Band Interleaved by Pixel, R = Band Interleaved by Row, S = Band Sequential'
      - id: num_blocks_per_row
        -orig-id: nbpr
        type: str
        size: 4
      - id: num_blocks_per_col
        -orig-id: nbpc
        type: str
        size: 4
      - id: num_pixels_per_block_horz
        -orig-id: nppbh
        type: str
        size: 4
      - id: num_pixels_per_block_vert
        -orig-id: nppbv
        type: str
        size: 4
      - id: num_pixels_per_band
        -orig-id: nbpp
        type: str
        size: 2
      - id: img_display_level
        -orig-id: idlvl
        type: str
        size: 3
      - id: attachment_level
        -orig-id: ialvl
        type: str
        size: 3
      - id: img_location
        -orig-id: iloc
        type: str
        size: 10
      - id: img_magnification
        -orig-id: imag
        type: str
        size: 4
      - id: user_def_img_data_len
        -orig-id: udidl
        type: str
        size: 5
      - id: user_def_overflow
        -orig-id: udofl
        type: str
        size: 3
        if: user_def_img_data_len.to_i != 0
      - id: user_def_img_data
        -orig-id: udid
        type: u1
        if: user_def_img_data_len.to_i > 2
        repeat: expr
        repeat-expr: user_def_img_data_len.to_i - 3
      - id: image_extended_sub_header
        type: tre_header
  band_info:
    seq:
      - id: representation
        -orig-id: irepband
        type: str
        size: 2
        doc: 'Indicates processing required to display the nth band of image w.r.t. the general image type recorded by IREP field'
      - id: subcategory
        -orig-id: isubcat
        type: str
        size: 6
      - id: img_filter_condition
        -orig-id: ifc
        contents: 'N'
      - id: img_filter_code
        -orig-id: imflt
        type: str
        size: 3
        doc: 'Reserved'
      - id: num_luts
        -orig-id: nluts
        type: str
        size: 1
      - id: num_lut_entries
        -orig-id: nelut
        type: str
        size: 5
        if: num_luts.to_i != 0
        doc: 'Number of entries in each of the LUTs for the nth image band'
      - id: luts
        -orig-id: lutd
        size: num_lut_entries.to_i
        repeat: expr
        repeat-expr: num_luts.to_i
  image_comment:
    seq:
      - type: str
        size: 80
  image_data_mask:
    instances:
      tpxcd_size:
        value: "(tpxcdlnth % 8 == 0 ? tpxcdlnth : tpxcdlnth + (8 - tpxcdlnth % 8)) / 8"
      bmrtmr_count:
        value: >
          _parent.image_sub_header.num_blocks_per_row.to_i * _parent.image_sub_header.num_blocks_per_col.to_i * 
          (_parent.image_sub_header.img_mode != 'S' ? 
            1 :  
            (_parent.image_sub_header.num_bands.to_i != 0 ?
              _parent.image_sub_header.num_bands.to_i : 
              _parent.image_sub_header.num_multispectral_bands.to_i))
      has_bmr:
        value: bmrlnth != 0
      has_tmr:
        value: tmrlnth != 0
      bmrbnd_size: 
        value: "has_bmr ? bmrtmr_count * 4 : 0"
      tmrbnd_size:
        value: "has_tmr ? bmrtmr_count * 4 : 0"
      total_size:
        value: 4 + 2 + 2 + 2 + tpxcd_size + bmrbnd_size + tmrbnd_size
    seq:
      - id: blocked_img_data_offset
        -orig-id: imdatoff
        type: u4
      - id: bmrlnth
        type: u2
        doc: 'Block Mask Record Length'
      - id: tmrlnth
        type: u2
        doc: 'Pad Pixel Mask Record Length'
      - id: tpxcdlnth
        type: u2
        doc: 'Pad Output Pixel Code Length'
      - id: tpxcd
        size: tpxcd_size
        doc: 'Pad Output Pixel Code'
      - id: bmrbnd
        type: u4
        repeat: expr
        repeat-expr: bmrtmr_count
        if: has_bmr
        doc: 'Block n, Band m Offset'
      - id: tmrbnd
        type: u4
        repeat: expr
        repeat-expr: bmrtmr_count
        if: has_tmr
        doc: 'Pad Pixel n, Band m'
  graphics_segment:
    params:
      - id: idx
        type: u2
    seq:
      - id: graphic_sub_header
        type: graphic_sub_header
      - id: graphic_data_field
        size: _parent.header.lnnfo[idx].length_graphic_segment.to_i
  graphic_sub_header:
    seq:
      - id: file_part_type_sy
        -orig-id: sy
        contents: 'SY'
      - id: graphic_id
        -orig-id: sid
        type: str
        size: 10
      - id: graphic_name
        -orig-id: sname
        type: str
        size: 20
      - id: graphic_classification
        -orig-id: sclasnfo
        type: clasnfo
      - id: encryption
        -orig-id: encryp
        type: encrypt
      - id: graphic_type
        -orig-id: sfmt
        contents: 'C'
      - id: reserved1
        -orig-id: sstruct
        type: str
        size: 13
        doc: 'Reserved'
      - id: graphic_display_level
        -orig-id: sdlvl
        type: str
        size: 3
      - id: graphic_attachment_level
        -orig-id: salvl
        type: str
        size: 3
      - id: graphic_location
        -orig-id: sloc
        type: str
        size: 10
      - id: first_graphic_bound_loc
        -orig-id: sbnd1
        type: str
        size: 10
      - id: graphic_color
        -orig-id: scolor
        type: str
        size: 1
      - id: second_graphic_bound_loc
        -orig-id: sbnd2
        type: str
        size: 10
      - id: reserved2
        -orig-id: sres2
        type: str
        size: 2
        doc: 'Reserved'
      - id: graphics_extended_sub_header
        type: tre_header
  tre_header:
    seq:
      - id: header_data_length
        -orig-id: hdl
        type: str
        size: 5
      - id: header_overflow
        -orig-id: ofl
        type: str
        size: 3
        if: header_data_length.to_i != 0
      - id: header_data
        type: u1
        if: header_data_length.to_i > 2
        repeat: expr
        repeat-expr: header_data_length.to_i - 3
  text_segment:
    params:
      - id: idx
        type: u2
    seq:
      - id: text_sub_header
        size: 1
      - id: text_data_field
        size: _parent.header.ltnfo[idx].length_text_segment.to_i
  text_sub_header:
    seq:
      - id: text_date_time
        -orig-id: txtdt
        type: str
        size: 14
      - id: text_title
        -orig-id: txtitl
        type: str
        size: 80
      - id: text_security_class
        -orig-id: tclasnfo
        type: clasnfo
      - id: encryp
        type: encrypt
      - id: text_format
        -orig-id: txtfmt
        type: str
        size: 3
        doc: 'MTF (USMTF see MIL-STD-6040), STA (indicates BCS), UT1 (indicates ECS), U8S'
      - id: text_extended_sub_header
        type: tre_header
  data_extension_segment:
    params:
      - id: idx
        type: u2
    seq:
      - id: data_sub_header
        type: data_sub_header
        size: _parent.header.ldnfo[idx].length_data_extension_subheader.to_i
      - id: data_data_field
        size: _parent.header.ldnfo[idx].length_data_extension_segment.to_i
  data_sub_header_base:
    seq:
      - id: file_part_type_de
        -orig-id: de
        contents: 'DE'
        doc: 'File Part Type desigantor for Data Extension'
      - id: desid
        type: str
        size: 25
      - id: data_definition_version
        -orig-id: desver
        type: str
        size: 2
      - id: declasnfo
        type: clasnfo
  data_sub_header:
    instances:
      tre_ofl:
        value: des_base.desid == 'TRE_OVERFLOW'
    seq:
      - id: des_base
        type: data_sub_header_base
      - id: overflowed_header_type
        -orig-id: desoflw
        type: str
        size: 6
        if: tre_ofl
      - id: data_item_overflowed
        -orig-id: desitem
        type: str
        size: 3
        if: tre_ofl
      - id: des_defined_subheader_fields_len
        -orig-id: desshl
        type: str
        size: 4
      - id: desshf
        type: str
        size: des_defined_subheader_fields_len.to_i
      - id: des_defined_data_field
        -orig-id: desdata
        type: str
        size-eos: true
  data_sub_header_tre:
    seq:
      - id: des_base
        type: data_sub_header_base
      - id: overflowed_header_type
        -orig-id: desoflw
        type: str
        size: 6
        if: des_base.desid == 'TRE_OVERFLOW'
      - id: data_item_overflowed
        -orig-id: desitem
        type: str
        size: 3
        if: des_base.desid == 'TRE_OVERFLOW'
      - id: des_defined_subheader_fields_len
        -orig-id: desshl
        type: str
        size: 4
      - id: des_defined_data_field
        -orig-id: desdata
        type: str
        size: des_defined_subheader_fields_len.to_i
  data_sub_header_streaming:
    seq:
      - id: des_base
        type: data_sub_header_base
      - id: des_defined_subheader_fields_len
        -orig-id: desshl
        type: str
        size: 4
      - id: sfh_l1
        type: str
        size: 7
        doc: 'SFH Length 1: number of bytes in sfh_dr field'
      - id: sfh_delim1
        type: u4
        doc: 'Shall contain the value 0x0A6E1D97.'
      - id: sfh_dr
        type: u1
        repeat: expr
        repeat-expr: sfh_l1.to_i
      - id: sfh_delim2
        type: u4
        doc: 'Shall contain the value 0x0ECA14BF.'
      - id: sfh_l2
        type: str
        size: 7
        doc: 'A repeat of sfh_l1.'
    doc: 'Streaming file Header Data Extension Segment Subheader'
  reserved_extension_segment:
    params:
      - id: idx
        type: u2
    seq:
      - id: reserved_sub_header
        type: reserved_sub_header
        size: _parent.header.lrnfo[idx].length_reserved_extension_subheader.to_i
      - id: reserved_data_field
        size: _parent.header.lrnfo[idx].length_reserved_extension_segment.to_i
  reserved_sub_header:
    seq:
      - id: file_part_type_re
        -orig-id: re
        contents: 'RE'
      - id: res_type_id
        -orig-id: resid
        type: str
        size: 25
      - id: res_version
        -orig-id: resver
        type: str
        size: 2
      - id: reclasnfo
        type: clasnfo
      - id: res_user_defined_subheader_length
        -orig-id: resshl
        type: str
        size: 4
      - id: res_user_defined_subheader_fields
        -orig-id: resshf
        type: str
        size: res_user_defined_subheader_length.to_i
      - id: res_user_defined_data
        -orig-id: resdata
        type: str
        size-eos: true
  tre:
    seq:
      - id: extension_type_id
        -orig-id: etag
        type: str
        size: 6
        doc: 'RETAG or CETAG'
      - id: edata_length
        -orig-id: el
        type: str
        size: 5
        doc: 'REL or CEL'
      - id: edata
        type: str
        size: edata_length.to_i
        doc: 'REDATA or CEDATA'