{
  "fileFormatID": 993,
  "formatName": "DjVu File Format",
  "version": null,
  "formatDescription": "The DjVu file format is an image file format used primarily for storing scanned documents. The format, developed by AT&T Labs, is based on the Interchange File format. There are three elements that comprise a DjVu encoded image file: the mask which is encoded using the JB2 algorithm; the background encoded using the wavelet-based compression IW44; and the foreground, containing the colour of the text and the line drawings, also encoding using IW44. The background and foreground are usually lower resolution (100 dpi) colour images with the mask at a higher level resolution (e.g. 300 dpi).",
  "releaseDate": null,
  "binaryFileFormat": "Text",
  "formatNote": null,
  "lastUpdatedDate": "02 Sep 2026",
  "formatProvenance": "v.120- Updated description as part of PRONOM Research Week 2024. Submitted by the Digital Research Alliance of Canada - Federated Research Data Repository / Alliance de recherche num\u00e9rique du Canada - D\u00e9p\u00f4t f\u00e9d\u00e9r\u00e9 de donn\u00e9es de recherche; v.125- Updated description to correct definition due to previous mistake. Submitted by the Digital Research Alliance of Canada - Federated Research Data Repository / Alliance de recherche num\u00e9rique du Canada - D\u00e9p\u00f4t f\u00e9d\u00e9r\u00e9 de donn\u00e9es de recherche",
  "formatSourceDate": "08 Jan 2010",
  "formatDisclosure": null,
  "formatEnvironment": null,
  "formatRisk": null,
  "formatAliases": null,
  "formatTypes": "Image (Raster)",
  "formatFamilies": null,
  "identifiers": [
    {
      "identifierText": "fmt/255",
      "identifierType": "PUID"
    },
    {
      "identifierText": "image/vnd.djvu",
      "identifierType": "MIME"
    },
    {
      "identifierText": "image/x-djvu",
      "identifierType": "MIME"
    }
  ],
  "internalSignatures": [
    {
      "signatureID": 411,
      "name": "DjVu File Format",
      "note": "Header ASCII: AT&T  followed by container Chunk FORM, then either DJVMDIRM or DJVUINFO as secondary identifiers to DjVu document type. This is a generic signature which will identify all DjVu files up to DjVu specifications v3. No distinction is made between single or multi page documents, or any internal image encoding.",
      "byteSequences": [
        {
          "positionType": "Absolute from BOF",
          "offset": 0,
          "maxOffset": null,
          "byteSequence": "41542654464F524D{4}(444A564D4449524D|444A5655494E464F)",
          "endianness": null,
          "byteSequenceID": 517
        }
      ],
      "provenance": "Ongoing DROID research work, following request from National Library Board Singapore."
    }
  ],
  "externalSignatures": [
    {
      "externalSignature": "djvu",
      "signatureType": "File extension"
    },
    {
      "externalSignature": "djv",
      "signatureType": "File extension"
    }
  ],
  "relationships": [],
  "supportedBy": [
    151
  ],
  "developedBy": [
    151
  ],
  "containerSignatures": [],
  "submittedBy": [
    149
  ]
}