The DjVu library distributed as part of the open-source package DjVuLibre has become the reference implementation for the DjVu format. Independent technologist Brewster Kahle in a 2004 talk on IT Conversations discussed the benefits of allowing easier access to DjVu files. The declared higher compression ratio (and thus smaller file size), and the claimed ease of converting large volumes of text into DjVu format, were other arguments for DjVu's superiority over PDF in the technology landscape of 2004. Prior to the standardization of PDF in 2008, DjVu had been considered superior due to it being an open file format in contrast to the proprietary nature of PDF at the time. Howard, Patrice Simard, and Yoshua Bengio at AT&T Labs from 1996 to 2001. The DjVu technology was originally developed by Yann LeCun, Léon Bottou, Patrick Haffner, Paul G. DjVu is supported by a number of multi-format document viewers and e-book reader software on Linux ( Okular, Evince, Zathura), Windows ( Okular, SumatraPDF), and Android ( Document Viewer, FBReader, EBookDroid, PocketBook). Like PDF, DjVu can contain an OCR text layer, making it easy to perform copy and paste and text search operations.įree creators, manipulators, converters, Web browser plug-ins, and desktop viewers are available. The DjVu developers report that color magazine pages compress to 40–70 kB, black-and-white technical papers compress to 15–40 kB, and ancient manuscripts compress to around 100 kB a satisfactory JPEG image typically requires 500 kB. This allows high-quality, readable images to be stored in a minimum of space, so that they can be made available on the web.ĭjVu has been promoted as providing smaller files than PDF for most scanned documents. It uses technologies such as image layer separation of text and background/images, progressive loading, arithmetic coding, and lossy compression for bitonal ( monochrome) images. They do not encode information that is specific to the application software, hardware, or operating system used to create or view the document.DjVu ( / ˌ d eɪ ʒ ɑː ˈ v uː/ DAY-zhah- VOO, like French " déjà vu" ) 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. A PDF file can be any length, contain any number of fonts and images and is designed to enable the creation and transfer of printer-ready output.Įach PDF file encapsulates a complete description of a 2D document (and, with the advent of Acrobat 3D, embedded 3D documents) that includes the text, fonts, images and 2D vector graphics that compose the document. PDF is a file format developed by Adobe Systems for representing documents in a manner that is separate from the original operating system, application or hardware from where it was originally created. Ultimately this results in dramatically reduced file sizes. The background and foreground images are compressed using an algorithm named IW44 with the mask image compressed using JB2. DjVu files are typically seperated into three images - the background and foreground (around 100 dpi) and the mask image which is higher resolution (e.g. It promises smaller files sizes than standard PDF's and is therefore perceived to be superior to PDF's primarily due to it's higher compression ratio. There are a whole host of DjVu viewers, browser plugins, encoders and decoders available on both Mac and Windows.ĭjVu was initially developed by Yann LeCun, L�on Bottou, Patrick Haffner, and Paul G. It allows for scanned documents, photographs and very high resolution images to be distributed via the internet. DjVu was initially developed by AT&T and is used as an image compression technology that is an open sourced alternative to PDF.
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