Packwood, Roger Andrew (1986) Progressive transmission and display of static images. PhD thesis, University of Warwick.

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Abstract

Progressive image transmission has been studied for some time in association with image displays connected to remote image sources, by communications channels of insufficient data rate to give subjectively near instantaneous transmission. Part of the work presented in this thesis addresses the progressive transmission problem constrained that the final displayed image is exactly identical to the source image with no redundant data transmitted. The remainder of the work presented is concerned with producing the subjectively best image for display from the information transmitted throughout the progression. Quad-tree and binary-tree based progressive transmission techniques are reviewed, especially an exactly invertible table based binary-tree technique. An algorithm is presented that replaces the table look-up in this technique, typically reducing implementation cost, and results are presented for the subjective improvement using interpolation of the display images. The relevance of the interpolation technique to focusing the progressive sequence on some part of the image is also discussed.

Some aspects of transform coding for progressive transmission are reviewed, intermediate image resolution and most importantly problems associated with the coding being exactly invertible. Starting with the two-dimensional case, an algorithm is developed, that judged by the progressive display image can mimic the behaviour of a linear transform while also being exactly invertible (no quantisation). This leads to a mean/difference transform similar to the binary-tree technique. The mimic algorithm is developed to operate on n-dimensions and used to mimic an eight-dimensional cosine transform. Photographic and numerical results of the application of this algorithm to image data are presented. An area transform, interpolation to disguise block boundaries and bit allocation to coefficients, based on the cosine mimic transform are developed and results presented.

Item Type:	Thesis (PhD)
Subjects:	Q Science > QA Mathematics T Technology > TA Engineering (General). Civil engineering (General) T Technology > TK Electrical engineering. Electronics Nuclear engineering
Library of Congress Subject Headings (LCSH):	Image analysis, Image transmission, Coding theory
Official Date:	September 1986
Dates:	Date Event September 1986 UNSPECIFIED
Institution:	University of Warwick
Theses Department:	Department of Computer Science
Thesis Type:	PhD
Publication Status:	Unpublished
Supervisor(s)/Advisor:	Martin, George
Sponsors:	Science and Engineering Research Council (Great Britain)
Extent:	209 leaves : illustrations, photographs
Language:	eng

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