To speed download times, DjVu uses a progressive coding technique that brings up the initial version of the page very quickly and improves its visual quality as more bits arrive. For example, the text of a typical magazine page appears in just three seconds over a 56KBps modem connection. In another second or two, the first version of the picture and background appear. After a few more seconds, the final full quality version of the page is completed. A Comparison of DjVu with PDF Two major problem areas we have encountered using PDF for E-Reserves are file size and print speed.
Print speed appears to be most problematic for users who elect to print via a network printer.
These problems have prompted us to explore other avenues in providing an electronic reserve service. I recently conducted a comparison test of DjVu and PDF formats to determine if DjVu might be better suited for an electronic reserve initiative. The document links to the right can be used to compare the download performance of the two file formats.