{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,8,15]],"date-time":"2025-08-15T00:00:54Z","timestamp":1755216054604,"version":"3.43.0"},"reference-count":0,"publisher":"Walter de Gruyter GmbH","issue":"1","license":[{"start":{"date-parts":[[2015,1,1]],"date-time":"2015-01-01T00:00:00Z","timestamp":1420070400000},"content-version":"unspecified","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2015,1,1]]},"abstract":"<jats:title>Abstract<\/jats:title>\n               <jats:p>This paper presents a novel variance of subregions\nand discrete cosine transform based image-coding\nscheme. The proposed encoder divides the input image\ninto a number of non-overlapping blocks. The coefficients\nin each block are then transformed into their spatial frequencies\nusing a discrete cosine transform. Coefficients\nwith the same spatial frequency index at different blocks\nare put together generating a number of matrices, where\neach matrix contains coefficients of a particular spatial\nfrequency index. The matrix containing DC coefficients is\nlosslessly coded to preserve its visually important information.\nMatrices containing high frequency coefficients\nare coded using a variance of sub-regions based encoding\nalgorithm proposed in this paper. Perceptual weights\nare used to regulate the threshold value required in the\ncoding process of the high frequency matrices. An extension\nof the system to the progressive image transmission\nis also developed. The proposed coding scheme, JPEG and\nJPEG2000were applied to a number of test images. Results\nshow that the proposed coding scheme outperforms JPEG\nand JPEG2000 subjectively and objectively at low compression\nratios. Results also indicate that the proposed codec\ndecoded images exhibit superior subjective quality at high\ncompression ratios compared to that of JPEG, while offering\nsatisfactory results to that of JPEG2000.<\/jats:p>","DOI":"10.1515\/comp-2015-0003","type":"journal-article","created":{"date-parts":[[2015,8,11]],"date-time":"2015-08-11T13:01:38Z","timestamp":1439298098000},"page":"13-21","source":"Crossref","is-referenced-by-count":0,"title":["DCT image codec using variance of sub-regions"],"prefix":"10.1515","volume":"5","author":[{"given":"Pooneh Bagheri","family":"Zadeh","sequence":"first","affiliation":[{"name":"Bagheri Zadeh School of Computer Science and Informatics , De Montfort University , U.K."}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Akbar Sheikh","family":"Akbari","sequence":"additional","affiliation":[{"name":"School of Computing, Creative Technology and Engineering, Faculty of Arts, Environment and Technology , Leeds Beckett University , U.K."}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Tom","family":"Buggy","sequence":"additional","affiliation":[{"name":"Division of Communication, Network and Electronic Engineering, School of Engineering & Computing , Glasgow Caledonian University , 70 Cowcaddens Road, Glasgow G4 0BA, UK"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"374","published-online":{"date-parts":[[2015,8,11]]},"container-title":["Open Computer Science"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.degruyter.com\/view\/journals\/comp\/5\/1\/article-p13.xml","content-type":"text\/html","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/www.degruyterbrill.com\/document\/doi\/10.1515\/comp-2015-0003\/xml","content-type":"application\/xml","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/www.degruyterbrill.com\/document\/doi\/10.1515\/comp-2015-0003\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,8,3]],"date-time":"2025-08-03T01:13:46Z","timestamp":1754183626000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.degruyterbrill.com\/document\/doi\/10.1515\/comp-2015-0003\/html"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2015,1,1]]},"references-count":0,"journal-issue":{"issue":"1","published-online":{"date-parts":[[2015,8,11]]},"published-print":{"date-parts":[[2015,1,1]]}},"alternative-id":["10.1515\/comp-2015-0003"],"URL":"https:\/\/doi.org\/10.1515\/comp-2015-0003","relation":{},"ISSN":["2299-1093"],"issn-type":[{"type":"electronic","value":"2299-1093"}],"subject":[],"published":{"date-parts":[[2015,1,1]]}}}