{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,28]],"date-time":"2026-03-28T17:58:48Z","timestamp":1774720728527,"version":"3.50.1"},"reference-count":22,"publisher":"Hindawi Limited","license":[{"start":{"date-parts":[[2012,1,1]],"date-time":"2012-01-01T00:00:00Z","timestamp":1325376000000},"content-version":"unspecified","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/3.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Computational and Mathematical Methods in Medicine"],"published-print":{"date-parts":[[2012]]},"abstract":"<jats:p>The nonlocal means (NLM) filter has been proven to be an efficient feature-preserved denoising method and can be applied to remove noise in the magnetic resonance (MR) images. To suppress noise more efficiently, we present a novel NLM filter based on the discrete cosine transform (DCT). Instead of computing similarity weights using the gray level information directly, the proposed method calculates similarity weights in the DCT subspace of neighborhood. Due to promising characteristics of DCT, such as low data correlation and high energy compaction, the proposed filter is naturally endowed with more accurate estimation of weights thus enhances denoising effectively. The performance of the proposed filter is evaluated qualitatively and quantitatively together with two other NLM filters, namely, the original NLM filter and the unbiased NLM (UNLM) filter. Experimental results demonstrate that the proposed filter achieves better denoising performance in MRI compared to the others.<\/jats:p>","DOI":"10.1155\/2012\/232685","type":"journal-article","created":{"date-parts":[[2012,3,7]],"date-time":"2012-03-07T16:00:46Z","timestamp":1331136046000},"page":"1-14","source":"Crossref","is-referenced-by-count":39,"title":["Improved DCT-Based Nonlocal Means Filter for MR Images Denoising"],"prefix":"10.1155","volume":"2012","author":[{"given":"Jinrong","family":"Hu","sequence":"first","affiliation":[{"name":"College of Computer Science, Sichuan University, Chengdu 610064, China"},{"name":"College of Computer Science, Sichuan University, Chengdu 610065, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yifei","family":"Pu","sequence":"additional","affiliation":[{"name":"College of Computer Science, Sichuan University, Chengdu 610064, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Xi","family":"Wu","sequence":"additional","affiliation":[{"name":"College of Electronic and Information Engineering, Sichuan University, Chengdu 610064, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yi","family":"Zhang","sequence":"additional","affiliation":[{"name":"College of Computer Science, Sichuan University, Chengdu 610064, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jiliu","family":"Zhou","sequence":"additional","affiliation":[{"name":"College of Computer Science, Sichuan University, Chengdu 610064, China"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"98","reference":[{"key":"1","doi-asserted-by":"publisher","DOI":"10.1109\/79.560324"},{"key":"2","doi-asserted-by":"publisher","DOI":"10.1109\/34.56205"},{"key":"3","doi-asserted-by":"publisher","DOI":"10.1109\/42.141646"},{"key":"5","doi-asserted-by":"publisher","DOI":"10.1002\/mrm.1910210213"},{"key":"6","doi-asserted-by":"publisher","DOI":"10.1109\/18.382009"},{"key":"7","doi-asserted-by":"publisher","DOI":"10.1109\/83.791966"},{"key":"8","doi-asserted-by":"publisher","DOI":"10.1016\/S0730-725X(99)00100-9"},{"key":"9","doi-asserted-by":"publisher","DOI":"10.1016\/S0730-725X(99)00128-9"},{"key":"10","doi-asserted-by":"publisher","DOI":"10.1016\/j.mri.2010.03.013"},{"key":"11","doi-asserted-by":"publisher","DOI":"10.1137\/040616024"},{"key":"14","doi-asserted-by":"publisher","DOI":"10.1109\/TMI.2007.906087"},{"key":"15","doi-asserted-by":"publisher","DOI":"10.1016\/j.media.2008.02.004"},{"key":"17","doi-asserted-by":"publisher","DOI":"10.1109\/TMI.2008.927338"},{"key":"18","doi-asserted-by":"publisher","DOI":"10.1002\/jmri.22003"},{"key":"19","doi-asserted-by":"publisher","DOI":"10.1016\/j.mri.2010.06.023"},{"key":"20","doi-asserted-by":"publisher","DOI":"10.1109\/T-C.1974.223784"},{"issue":"6","key":"21","doi-asserted-by":"crossref","first-page":"359","DOI":"10.1049\/ip-f-1.1981.0061","volume":"128","year":"1981","journal-title":"Communications, Radar and Signal Processing, IEE Proceedings F"},{"key":"22","year":"2003"},{"key":"25","doi-asserted-by":"publisher","DOI":"10.1002\/mrm.1910340618"},{"issue":"2","key":"26","doi-asserted-by":"crossref","first-page":"331","DOI":"10.1002\/mrm.1910360222","volume":"36","year":"1996","journal-title":"Magnetic Resonance in Medicine"},{"key":"32","doi-asserted-by":"publisher","DOI":"10.1109\/42.816072"},{"issue":"3","key":"33","doi-asserted-by":"crossref","first-page":"463","DOI":"10.1109\/42.712135","volume":"17","year":"1998","journal-title":"IEEE Transactions on Medical Imaging"}],"container-title":["Computational and Mathematical Methods in Medicine"],"original-title":[],"language":"en","link":[{"URL":"http:\/\/downloads.hindawi.com\/journals\/cmmm\/2012\/232685.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"http:\/\/downloads.hindawi.com\/journals\/cmmm\/2012\/232685.xml","content-type":"application\/xml","content-version":"vor","intended-application":"text-mining"},{"URL":"http:\/\/downloads.hindawi.com\/journals\/cmmm\/2012\/232685.pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2017,6,20]],"date-time":"2017-06-20T11:19:28Z","timestamp":1497957568000},"score":1,"resource":{"primary":{"URL":"http:\/\/www.hindawi.com\/journals\/cmmm\/2012\/232685\/"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2012]]},"references-count":22,"alternative-id":["232685","232685"],"URL":"https:\/\/doi.org\/10.1155\/2012\/232685","relation":{},"ISSN":["1748-670X","1748-6718"],"issn-type":[{"value":"1748-670X","type":"print"},{"value":"1748-6718","type":"electronic"}],"subject":[],"published":{"date-parts":[[2012]]}}}