We have touched on some of the most important, well established and
mature SP methods appropriate to the NII, but
a wide variety of special techniques can also be found in particular
applications.
Common examples include motion compensation in video compression,
where automatic extraction of motion in an image can permit significantly
improved compression, and related deblurring algorithms for improving
still images taken by or of moving objects. Worthy of mention also
are synchronization methods, noise removal and enhancement techniques
for improving the perceived quality of noisy speech and noisy images.
The applications of SP are too numerous to list,
but the depth and breadth of its impact are illustrated by several examples
relevant to the NII. In
Chapter 
we return to more detailed
consideration of a few of them.
Health Care Biomedical data acquisition and processing, including such sources as CAT scans, fetal heart monitors, EKGs, and high-resolution rendering from imaging devices. PET and SPECT illustrate associated inverse problems. Also, Picture Archival and Communications Systems (PACs) require all aspects of digital communications SP as well as prospective content-extraction algorithms.
Education The recent acquisition by NASA of the photos of comet fragments hitting Jupiter, and the dissemination of the data via the ethernet to scientists and grade students alike demonstrate the wide impact that image acquisition, storage, transmission, and display can have at all levels of education. Rapid access to new and old information through the NII can partially compensate for outdated textbooks and otherwise inadequate facilities.
Geographical Information Systems Huge databases are being generated for scientific, government, and commercial purposes that can be viewed as multidimensional maps of the earth and of the environment. Basic SP for communications and storage already makes these data more accessible, but enhanced SP tools will increase its utility for wider audiences.
Resource Exploration Oil and natural gas exploration commonly use DSP techniques to acquire and to process seismic signals. SP place a similar role in underwater and other geophysical signal analysis.
Modern Communication Networks Digital communications use DSP in modems, cellular telephones, commercial switching equipment, and teleconferencing.
Consumer Electronics Sophisticated DSP is used in compact disk players, audio processors, radios, computer graphics interfaces, and video games.
Automatic Navigation The older LORAN and more recent global positioning satellite (GPS) navigation systems are widely used for accurate navigation. Both systems use sophisticated SP algorithms to accurately estimate the user's position. Auto makers and publishers already offer prototype systems with on-line maps and travelers' directions.
Image Processing Image processing is used in many areas. For example, commercial silk screening now uses image processing algorithms to manipulate images, to separate colors, and to produce the masks used in the screening process. The fine arts have used SP analytic techniques to detect overpainting and to establish authorship and dating from radiographic images.
Entertainment SP is involved in many entertainment applications such as interactive video games and other multimedia applications incorporating sound, graphics, and imagery. Variations on some of these applications can support rather than detract from education. Multimedia access to information resources can be fun and can provide user-customized capabilities for motivation building, interactive measures of attentivity, and reward mechanisms for cooperative and successful behavior.
Business and Finance Videoconferencing enhances remote project planning, assessment, and collaboration. Multimedia methods are already used for remote processing by insurance companies, the real-estate industry, and direct marketing companies.
The previously described applications are already mature, although rapid and radical changes have occurred during the past decade.