Identical shapes on the page, such as multiple occurrences of a The JB2 encoding method identifies nearly The mask image is compressed using a method called JB2 Images are then compressed using a wavelet-based compression algorithm Image is a high-resolution bilevel image (e.g., 300 dpi) and is Typically lower-resolution color images (e.g., 100 dpi) the mask Is first separated into three images: a background image, a foreground PDF file can contain both vector and raster graphics.ĭjVu divides a single image into many different images, thenĬompresses them separately. The main differenceīetween DjVu and PDF is that DjVu is a pure raster file format while a Here are some relevant excerpts from Wikipedia:ĭjVu has been promoted as an alternative to PDF, promising smallerįiles than PDF for most scanned documents. You can read about the djvu file format here (with focus on the compression here), but the main difference is how the two formats compress the data. Especially on a page with characters (not selectable text associated with the characters) combined with images DjVu easily gets 20x smaller files at similar lossy quality.
The primary difference, apart from algorithms used for compression, is that an image in a DjVu file consists of multiple layers, each compressed separately, with optimized algorithms for the layer's data (monotone, color etc.), and recombined for display/printing. So in general, unless the DjVu file is compressed inefficiently to start with, you will always get a bigger PDF file, or you get a much worse quality image. The longer answer is that the possible storage of image data in PDF files is done in a less efficient way than is possible in the way DjVu does. The only reason that it is often used for doing so, is that it is one of the few formats (the other more well known ones are DjVu and TIFF), that allow you to store multiple (scanned) images in a single file. Even transfer it to your mobile device or other OS.The short answer is: PDF is not a good format for storing image data. Just open PDF in Preview.| – You get PDF that you can read in way that is most comfortable to you. So there is two advantages for converter:| – You don’t have to wait every time you open DjVu file. And lets say it, those PDF viewers are less comfortable than Mac’s Preview app. After conversion document can be opened with any reader supporting PDF (even mobile or portable).| | Why use converter instead of reader? Most of the readers are actually converters with integrated PDF viewer. DjVu To PDF Converter is an app that lets you easily convert any DjVu file to PDF document.DjVu To PDF Converter – DjVu To PDF Converter is an app that lets you easily convert any DjVu file to PDF document.
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