2) the converter from pdf to djvu, the program does not open PDF.
#Djvu to pdf small size license
It seems like the program is free, but it’s dangerous to use it, for any organization you can find a license with inappropriate restrictions. You already decide what license you are distributing? In the end, once the project is abandoned, write one central license !!! What a not serious approach. In the installer, gnu gpl is written, in the properties of the sourceforge gnu agpl project, in the program folder there is a doc directory, and there are still a bunch of licenses, including apache license v2. 1) With licenses nothing is clear at all, they are just rubbish there. A long bunch of authors are listed on a site that hasn’t existed for a long time (according to the web archive), but it feels like the school’s students created the program. I have never used it myself though.Not worth the attention. The letter "e" once (as a compressed bit image) and then records everyĪs for converting a djvu to a pdf without increasing the size, there is a program that claims it can do so called Scientific and Technical Document Utility (it is not free). Thus, instead ofĬompressing a letter "e" in a given font multiple times, it compresses Locations where each shape appears on the page. The bitmap of each unique shape separately, and then encodes the Particular character in a given font, style, and size. 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. The short answer is: PDF is not a good format for storing image data.