Format
JPEG Network Graphics
Summary
- Name
- JPEG Network Graphics
- Identifiers
-
- PUID: fmt/529
- MIME: image/x-jng
- Format type
- Image (Raster)
- Description
- JPEG Network Graphics (JNG) is a JPEG-based graphics file format which is closely related to PNG: it uses the PNG file structure (with a different signature) as a container format to wrap JPEG encoded image data. JNG was created as an adjunct to the MNG animation format, but may be used as a stand-alone format. JNG files embed an 8-bit or 12-bit JPEG datastream in order to store color data, and may embed another datastream (1, 2, 4, 8, 16 bit PNG, or 8 bit JPEG grayscale image) for transparency information. However, a JNG may contain two separate JPEG datastreams for color information (one eight-bit and one twelve-bit) to permit decoders that are unable to (or do not wish to) handle twelve-bit datastreams to display the eight-bit datastream instead, if one is present.
- File extensions
-
jng - Source
- Digital Preservation Department / The National Archives
Internal signatures
JNG
- Note
- BOF ‹JNG........JHDR EOF IEND®B`‚
Byte sequences
- Min Frag Length
- Absolute from BOF
- Offset
- 0
- Max offset
- 0
- Byte Sequence
8B4A4E470D0A1A0A000000104A484452- Endianness
- None
- Min Frag Length
- Absolute from EOF
- Offset
- 0
- Max offset
- 0
- Byte Sequence
49454E44AE426082- Endianness
- None