JBP-2021.2 Joint BIIF Profile for imagery interchange

What it is

A profile of ISO/IEC BIIF for two format communities

JBP-2021.2, the Joint BIIF Profile, is a joint NATO and United States specification that profiles ISO/IEC 12087-5, the Basic Image Interchange Format (BIIF), for transmitting and storing electronic imagery. It supports both the NATO Secondary Imagery Format (NSIF), the format NATO nations use under STANAG 4545, and the United States National Imagery Transmission Format Standard (NITFS), so a system built to it can exchange imagery with either community without a separate implementation for each. It is jointly authored and maintained by the STANAG 4545 Custodial Support Team and the NITFS Technical Board, and is approved for use by NATO Command, Control, Communications and Intelligence systems and by every department and agency of the United States Department of Defense.

Its obligations are written against packing (producing) and unpacking (rendering) implementations rather than against an organisation directly. That distinction matters for a quality manager reading this page rather than a software architect: this is a specification a development team builds and tests against, and the evidence an assessor wants relates to what the software does, not to a management system.

How a JBP file is structured

A JBP file is a file header, with or without data segments. Where segments exist, they follow a fixed order - all image segments, then all graphic segments, then all text segments - and every segment is a subheader immediately followed by its own data. Every displayable item is positioned using a shared Common Coordinate System, with coordinates always positive and nothing permitted outside its positive quadrant. A complexity level, marked no lower than the most demanding feature the file actually contains, sets the outer bound of what that file may use.

Within an image segment, the profile fixes how pixel coordinates are addressed, requires the declared band count to match the image data, and sets rules for how look-up tables are structured and used for display. Blocked images must start each block on a byte boundary and pad out to it. Every image or graphic segment carries a unique display level, an attached segment inherits its parent's display level, and an overlay's display level must exceed its attachment level. Text segment lines are delimited by a carriage return and line feed.

Registering an extension with the NTB

Where an implementation needs a Support Data Extension - a Tagged Record Extension or a Data Extension Segment - beyond what the base profile defines, and that extension is controlled or registered, it has to be registered with the NSG GWG NITFS Technical Board (NTB), together with its name and purpose, before it can be used. One that is not registered is invalid, and an implementation that does not recognise a given extension has to ignore it and keep interpreting the rest of the file rather than fail. Reserved Extension Segments are documented as a structure but currently precluded from use in a JBP file altogether, because the NTB does not yet maintain a registry for them - worth knowing before a team designs around one.

Security marking

The file header's overall security classification must be at least as high as the highest classification marked on any segment inside it, and every security field must carry valid data. The document also says, outside its formal requirements, that an implementation should always extract and display the classification data carried in a file's headers, and should not rely on a graphic overlay alone to convey security or handling instructions, because panning or zooming can move it out of view.

What counts as conformance

A packing implementation has to have a means of ensuring every file it produces stays within the complexity level the file declares. An unpacking implementation has to present content as the originator intended, and where it meets something it does not recognise or a conformance issue, it has to keep functioning and alert a system operator or administrator rather than fail outright. In practice, an assessor or a conformance test is checking segment presence and ordering, valid or correctly-defaulted field data, a complexity-level marking that matches the file's real content, genuine NTB registration for any extension identifier in use, and graceful handling of the unexpected.

JBP-2021.2 does not cover the physical handling, storage or network transport of imagery, who is authorised to see classified imagery, or the wider tasking and dissemination processes around an imagery system. It also does not restate the content of the compression, graphics and coordinate standards it invokes for particular techniques; it names the applicable standard and leaves the technical detail to it.

Standards it references

• STANAG 5500Background
• STANAG 2211Background
• ADatP-03Background