DjVu (pronounced "déjà vu") a set of compression technologies, a file format, and a software platform for the delivery over the Web of digital documents, scanned documents, and high resolution images.
DjVu documents download and display extremely quickly, and look exactly the same on all platforms with no compatibility problems due to fonts, colors, etc. DjVu can be seen as a superior alternative to PDF and PostScript for digital documents, to TIFF (and PDF) for scanned bitonal documents, to JPEG and JPEG2000 for photographs and pictures, and to GIF for large palettized images. DjVu is the only Web format that is practical for distributing high-resolution scanned documents in color. No other format comes close.
Typical DjVu file sizes are as follows:
* bitonal scanned documents: 5 to 30KB per page at 300dpi (3 to 10 times smaller than PDF or TIFF)
* color scanned documents: 30 to 100KB per page at 300dpi (5 to 10 times smaller than JPEG).
* photos: 2 times smaller than JPEG, about the same as JPEG-2000, but the decoder/renderer is progressive and has minimal memory requirements.
* palettized images: 2 times smaller than GIF (up to 10 times if it's mostly text).
* digital (non scanned) documents: between 1 and 3 times smaller than PDF or gzipped PS (depending on the amount of pictures), but rendering, page flipping, zooming, panning are incomparably faster, and the image quality on screen desplays is much better (antialiased text, etc).
More importantly, all DjVu images render very quickly and can be smoothly zoomed and panned. Pages of a document can be turned instantly, with no annoying delay.
DjVu is used by hundreds of academic, commercial, governmental, and non-commercial web sites around the world to distribute scanned documents, digital documents, and high-resolution photos.
A short technical description of DjVu is available here.
Demos, and general information about DjVu can be found at DjVuZone.org, or at LizardTech.com.
DjVu was originally developped at AT&T Labs-Research. In March 2000, AT&T sold DjVu to LizardTech Inc. who now distributes Windows/CE/Mac plug-ins, and commercial encoders.
DjVuLibre is an open source implementation of DjVu. See the credits/history page for more details.
More Details : http://djvu.sourceforge.net/
Free Online DjVu-PDF Converter : http://www.djvu-pdf.com/
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