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DjVu ( , like (フランス語:déjà vu) (:deʒavy)) 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. It uses technologies such as image layer separation of text and background/images, progressive loading, arithmetic coding, and lossy compression for bitonal (monochrome) images. This allows for high-quality, readable images to be stored in a minimum of space, so that they can be made available on the web. DjVu has been promoted as an alternative to PDF, promising smaller files than PDF for most scanned documents. 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. Like PDF, DjVu can contain an OCR text layer, making it easy to perform copy and paste and text search operations. Free browser plug-ins and desktop viewers from different developers are available from the djvu.org website. DjVu is supported by a number of multi-format document viewers and e-book reader software on Linux (Okular, Evince) and Windows (SumatraPDF). == History == The Djvu technology was originally developed〔 by Yann LeCun, Léon Bottou, Patrick Haffner, and Paul G. Howard at AT&T Labs from 1996 to 2001. Due to its declared higher compression ratio (and thus smaller file size) and the ease of converting large volumes of text into Djvu format, and because it is an open file format, some independent technologists (such as Brewster Kahle) have historically considered it superior to PDF. The DjVu library distributed as part of the open source package ''DjVuLibre'' has become the reference implementation for the DjVu format. DjVuLibre has been maintained and updated by the original developers of DjVu since 2002.〔http://djvu.sourceforge.net/〕 The DjVu file format specification has gone through a number of revisions: 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「DjVu」の詳細全文を読む スポンサード リンク
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