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Perceptual Image Compression in TelemedicineThe next era of space exploration, especially the "Mission to Planet Earth" will generate immense quantities of image data. For example, the Earth Observing System (EOS) is expected to generate in excess of one terabyte/day. NASA confronts a major technical challenge in managing this great flow of imagery: in collection, pre-processing, transmission to earth, archiving, and distribution to scientists at remote locations. Expected requirements in most of these areas clearly exceed current technology. Part of the solution to this problem lies in efficient image compression techniques. For much of this imagery, the ultimate consumer is the human eye. In this case image compression should be designed to match the visual capacities of the human observer. We have developed three techniques for optimizing image compression for the human viewer. The first consists of a formula, developed jointly with IBM and based on psychophysical measurements, that computes a DCT quantization matrix for any specified combination of viewing distance, display resolution, and display brightness. This DCT quantization matrix is used in most recent standards for digital image compression (JPEG, MPEG, CCITT H.261). The second technique optimizes the DCT quantization matrix for each individual image, based on the contents of the image. This is accomplished by means of a model of visual sensitivity to compression artifacts. The third technique extends the first two techniques to the realm of wavelet compression. Together these two techniques will allow systematic perceptual optimization of image compression in NASA imaging systems. Many of the image management challenges faced by NASA are mirrored in the field of telemedicine. Here too there are severe demands for transmission and archiving of large image databases, and the imagery is ultimately used primarily by human observers, such as radiologists. In this presentation I will describe some of our preliminary explorations of the applications of our technology to the special problems of telemedicine.
Document ID
20020040846
Acquisition Source
Ames Research Center
Document Type
Conference Paper
Authors
Watson, Andrew B.
(NASA Ames Research Center Moffett Field, CA United States)
Ahumada, Albert J., Jr.
(NASA Ames Research Center Moffett Field, CA United States)
Eckstein, Miguel
(Cedars-Sinai Medical Center Los Angeles, CA United States)
Null, Cynthia H.
Date Acquired
August 20, 2013
Publication Date
January 1, 1996
Subject Category
Aerospace Medicine
Meeting Information
Meeting: Technology 2006, Telemedicine Workshop
Country: Unknown
Start Date: October 29, 1996
End Date: October 31, 1996
Funding Number(s)
PROJECT: RTOP 199-06-12
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.

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