This demonstration is very light for the client. The images are stored on
the server in the EDM (proprietary) format. On the access to the image
fragment, the server software decodes the image region of interest, converts
it to losless JPEG, and then sends to the client
(which is Internet browser). The server-side script (written in Perl) is used for image directory
navigation. Java applet is used for image navigation in the browser.
You may compare how much faster it
takes to decode and retrieve the image region instead of retrieval the
entire image. In principle, no JPEG conversion is required if the image
region can be sent directly to the client in the EDM compressed form and
subsequently decoded on the client side. It will be much faster to access
the image in such a case, however it will require installation of a more complex
client software, which we have decided not to include into our
demonstration.
Credits: server dynamic-page loading script and client browser (c) A.Kolesnikov
encoding/decoding software (c) E. Ageenko
JPEG software is based on standard JPEG library (GNU license)
Document
Imaging