McColl, R. W. and Martin, Graham R. (1987) Quantisation of digitised colour images. University of Warwick. Department of Computer Science. (Department of Computer Science research report). (Unpublished)

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Abstract

Schemes for the quantisation of digitised colour images are investigated, in order to reduce their storage requirements. The schemes involve transforming the RGB vectors into CIE XYZ format, from which the luminance Y and chromaticity x,y values are drawn. The x, y values are further transformed to chromaticity vectors ζ, η in the MacAdam domain. Histograms are found for both the luminance and chromaticity data, and clustering algorithms are used to create the codebooks used to quantise the image. Careful attention is required to ensure that the quantised Y ζ η vectors do not lie outside the RGB space. Compression ratios of around 6:1 are achieved, with the chromaticity component requiring less than 1 bit-per-pel.

Item Type:	Report
Subjects:	T Technology > TA Engineering (General). Civil engineering (General)
Divisions:	Faculty of Science, Engineering and Medicine > Science > Computer Science
Library of Congress Subject Headings (LCSH):	Image compression
Series Name:	Department of Computer Science research report
Publisher:	University of Warwick. Department of Computer Science
Official Date:	November 1987
Dates:	Date Event November 1987 Completion
Number:	Number 112
Number of Pages:	25
DOI:	CS-RR-112
Institution:	University of Warwick
Theses Department:	Department of Computer Science
Status:	Not Peer Reviewed
Publication Status:	Unpublished
Funder:	Alvey Programme (Great Britain)
Grant number:	MMI085 (Alvey)
Related URLs:	Organisation

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