DjVu[a] is a computer file format designed primarily to store scanned documents, especially those containing a combination of text, line drawings, indexed color images, and photographs.
The DjVu technology was originally developed by Yann LeCun, Léon Bottou, Patrick Haffner, Paul G. Howard, Patrice Simard, and Yoshua Bengio at AT&T Labs from 1996 to 2001.
Independent technologist Brewster Kahle in a 2004 talk on IT Conversations discussed the benefits of allowing easier access to DjVu files.
During a number of years, significantly overlapping with the period when DjVu was being developed, there were no PDF viewers for free operating systems—a particular stumbling block was the rendering of vectorised fonts, which are essential for combining small file size with high resolution in PDF.
In the 2000s, with the growth of the World Wide Web and before widespread adoption of broadband, DjVu was often adopted by digital libraries as their format of choice, thanks to its integration with software like Greenstone[11] and the Internet Archive,[12] browser plugins which allowed advanced online browsing, smaller file size for comparable quality of book scans and other image-heavy documents[13] and support for embedding and searching full text from OCR.
Following is a single FORM chunk with a secondary identifier of either DJVU or DJVM for a single-page or a multi-page document, respectively.
The JB2 encoding method identifies nearly identical shapes on the page, such as multiple occurrences of a particular character in a given font, style, and size.
Optionally, these shapes may be mapped to UTF-8 codes (either by hand or potentially by a text recognition system) and stored in the DjVu file.
[1] Thus the DjView viewing application can't warn the user that glyph substitutions might have occurred, neither when opening a lossy compressed file, nor in the Information or Metadata dialogue boxes.
[3] The original authors distribute an open-source implementation named "DjVuLibre" under the GNU General Public License and a patent grant.
[22] The rights to the commercial development of the encoding software have been transferred to different companies over the years, including AT&T Corporation, LizardTech,[23] Celartem[24] and ePapyrus Solutions K.K.