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1- WHAT IS DJVU.
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================
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DjVu (pronounced "d<>j<EFBFBD> vu") a set of compression technologies, a file format,
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and a software platform for the delivery over the Web of digital documents,
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scanned documents, and high resolution images.
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DjVu documents download and display extremely quickly, and look exactly the
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same on all platforms. DjVu can be seen as superior alternative to PDF and
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Postscript for digital documents, to TIFF (and PDF) for scanned documents, to
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JPEG for photographs and pictures, and to GIF for large palettized
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images. DjVu is the only Web format that is practical for distributing
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high-resolution scanned documents in color. No other format comes close.
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Typical DjVu file sizes are as follows:
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- Bitonal scanned documents:
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5 to 30KB per page at 300dpi,
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3 to 10 times smaller than PDF or TIFF.
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- Color scanned documents:
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30 to 100KB per page at 300dpi,
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5 to 10 times smaller than JPEG.
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- Photos:
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2 times smaller than JPEG,
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about the same as JPEG-2000.
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- Palettized images:
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2 times smaller than GIF,
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up to 10 times if there is text.
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DjVu is used by hundreds of commercial, governmental, and non-commercial web
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sites around the world to distribute scanned documents, digital documents, and
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high-resolution photos.
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Demos, and general information about DjVu can be found at
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http://www.djvuzone.org, or at http://www.lizardtech.com.
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DjVu was originally developed at AT&T Labs-Research. AT&T sold DjVu to
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LizardTech Inc. in March 2000.
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2- WHAT IS DJVULIBRE?
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=====================
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In an effort to promote DjVu as a Web standard, LizardTech's management was
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enlightened enough to release the reference implementation of DjVu under the
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GNU GPL in October 2000. DjVuLibre (pronounced like the French "d<>j<EFBFBD> vu
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libre"), is an enhanced version of that code maintained by the original
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inventors of DjVu. It is compatible with LizardTech's DjVu software v3.5.
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DjVuLibre includes:
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- A standalone DjVu viewer for Unix under X11 (based on the Qt library).
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- A browser plugin that works with most Unix browsers, including:
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Netscape-4.x, Netscape-6.x, Mozilla, Galeon, Konqueror, and Opera.
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- A full-fledged wavelet-based compressor for pictures.
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- A simple compressor for bitonal (black and white) scanned pages.
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- A compressor for palettized images (a la GIF).
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- A full set of utilities to manipulate and assemble DjVu images and documents.
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- A set of decoders to convert DjVu to a number of other formats.
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- An up-to-date version of the C++ DjVu Reference Library
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Windows and Mac versions of the viewer/plug-in, as well as commercial versions
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of the compressors and OCR engines are available from LizardTech Inc.. The
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compressors provided here are slower, produce larger files, and sometimes
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lower quality images than the commercial compressors, but they do the job.
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A variety of free web-based conversion services are also available, including
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any2djvu.djvuzone.org, bib2web.djvuzone.org, and openlib.djvuzone.org.
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