Why Djvu and not PDF?

/ ManyRoads, Site / / 5 Comments

As many of you have probably noticed, I am in the process of uploading, and making available, documents that use a DJVU file format.  Perhaps a brief explanation of the rationale is in order. To quote the authors of DJVU:

Many products and technologies are available today for storing and distributing digital images. However, most of these technologies are slow and inconvenient for distributing high-resolution color photos, and woefully impractical for delivering high-resolution scanned documents in B&W and color, because the files they produce are prohibitively large, and the viewing software memory hungry.

With its ability to attain very high compression ratios while preserving crisp and legible text, DJVU has no rival when it comes to distributing scanned documents, particularly color documents. For this kind of applications, there is quite simply no practical alternative to DJVU.

DJVU is also an excellent format for distributing high-resolution photos, because its wavelet-based continuous tone image compression technology produces small files with very fast progressive display, seamless zooming and panning, and requires minimal memory in the client.

Although I have yet to convert any/all of our maps etc. I can say this about the speed of opening and closing large electronic “print” documents.  It can be as much as 1000% faster.  The reason is simple.  If the document is generated as an ‘indirect bundle document’ rather than as a ‘bundled document’ the pages load singly rather than ‘all at once’.  If your documents are large this can provide a huge time savings to the reader not to mention how it saves bandwidth on your web site.

Additionally, in my genealogy research I found that many of the sites I rely upon are heavy users of DJVU.  This especially applies to universities and other large archives, most notably in my case DLibra in Poland and GenWiki in Germany.

Recognizing that not everyone has the plugins necessary to  read DJVU documents,I have included an easy download for them.  Additionally I have included pointers on the installation and use of DJVU see the following:

You may also wish to view the DJVU Resources web page for more plugin options, etc.

Please let me know if you run into any serious difficulties with this archive and document presentation approach.