Browse Prior Art Database

Lossy Coding of Multi-band Continuous Tone Image Data

IP.com Disclosure Number: IPCOM000108478D
Original Publication Date: 1992-Jun-01
Included in the Prior Art Database: 2005-Mar-22
Document File: 2 page(s) / 60K

Publishing Venue

IBM

Related People

Feig, E: AUTHOR

Abstract

Disclosed is a lossy coding method for data compression of multi-band continuous tone image data, such as data obtained from remote sensing instruments as HIRIS, AVIRIS and other radar imaging tools, which accounts for the correlation among the various images.

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This is the abbreviated version, containing approximately 62% of the total text.

Lossy Coding of Multi-band Continuous Tone Image Data

       Disclosed is a lossy coding method for data compression
of multi-band continuous tone image data, such as data obtained from
remote sensing instruments as HIRIS, AVIRIS and other radar imaging
tools, which accounts for the correlation among the various images.

      Images are sectioned into blocks (say, 128 by 128, 64 by 64, or
any other size - not necessarily square or of sizes which are powers
of two).  Corresponding blocks of the various different bands are
handled simultaneously.  Some number K of prototypical images for the
block are chosen. The number K depends on the statistics of the
images, and has to be determined in each individual case.

      In a preferred embodiment with K = 1, the prototypical image is
the average of the corresponding blocks with some of the least
significant bits dropped off.  This prototypical image will be
denoted by P1.  For each image Ij, two constants aj,1 and bj,1 are
computed.  These are the approximate solutions (that is, a fixed bit
accuracy of the actual solution) to the matrix-vector equation

                            (Image Omitted)

where Ij(k) and P1(k) are the respective pixel values of the images
Ij and P1, and N is the total number of pixels in each image.
Difference images are then formed

                            (Image Omitted)

In a preferred embodiment with K = 2, two prototypical ima...