The transmission of digital imagery can impose significant demands on the resources of clients, servers, and the networks that connect them. With the explosive growth of the internet, the need for mechanisms that support rapid browsing of on-line imagery has become critical. This is particularly evident in scientific imagery. | Image Databases Search and Retrieval of Digital Imagery Edited by Vittorio Castelli Lawrence D. Bergman Copyright 2002 John Wiley Sons Inc. ISBNs 0-471-32116-8 Hardback 0-471-22463-4 Electronic 9 Transmission of Digital Imagery JEFFREY W. PERCIVAL University of Wisconsin Madison Wisconsin VITTORIO CASTELLI IBM . Watson Research Center Yorktown Heights New York INTRODUCTION The transmission of digital imagery can impose significant demands on the resources of clients servers and the networks that connect them. With the explosive growth of the internet the need for mechanisms that support rapid browsing of on-line imagery has become critical. This is particularly evident in scientific imagery. The increase in availability of publicly accessible scientific data archives on the Internet has changed the typical scientist s expectations about access to data. In the past scientific procedures produced proprietary Pl-owned data sets that if exchanged at all were usually exchanged through magnetic tape. Now the approach is to generate large online data archives using standardized data formats and allow direct access by researchers. For example NASA s Planetary Data System is a network of archive sites serving data from a number of solar system missions. The Earth-Observing System will use eight Distributed Active Archive Centers to provide access to the very large volume of data to be acquired. Although transmission bandwidth has been increasing with faster modems for personal networking upgrades to the Internet and the introduction of new networks such as Internet 2 and the Next Generation Internet there are still a number of reasons because of which bandwidth for image-transmission will continue to be a limited resource into the foreseeable future. Perhaps the most striking of these factors is the rapid increase in the resolution of digital imagery and hence the size of images to be transmitted. A case in point is the rapid increase in both pixel count and .
