Cosine transform priors for enhanced decoding of compressed images

A Storkey*, M Allan

*Corresponding author for this work

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

Image compression methods such as JPEG use quantisation of discrete cosine transform (DCT) coefficients of image blocks to produce lossy compression. During decoding, an inverse DCT of the quantised values is used to obtain the lossy image. These methods suffer from blocky effects from the region boundaries, and can produce poor representations of regions containing sharp edges. Such problems can be obvious artefacts in compressed images but also cause significant problems for many super-resolution algorithms. Prior information about the DCT coefficients of an image and the continuity between image blocks can be used to improve the decoding using the same compressed image information. This paper analyses empirical priors for DCT coefficients, and shows how they can be combined with block edge contiguity information to produce decoding methods which reduce the blockiness of images. We show that the use of DCT priors is generic can be useful in many other circumstances.

Original languageEnglish
Title of host publicationINTELLIGENT DAA ENGINEERING AND AUTOMATED LEARNING IDEAL 2004, PROCEEDINGS
EditorsZR Yang, R Everson, H Yin
Place of PublicationBERLIN
PublisherSpringer-Verlag Berlin Heidelberg
Pages533-539
Number of pages7
ISBN (Print)3-540-22881-0
DOIs
Publication statusPublished - 2004
Event5th International Conference on Intelligent Data Engineering and Automated Learning (IDEAL 2004) - Execter, United Kingdom
Duration: 25 Aug 200427 Aug 2004

Publication series

NameLECTURE NOTES IN COMPUTER SCIENCE
PublisherSPRINGER-VERLAG BERLIN
Volume3177
ISSN (Print)0302-9743

Conference

Conference5th International Conference on Intelligent Data Engineering and Automated Learning (IDEAL 2004)
CountryUnited Kingdom
Period25/08/0427/08/04

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