{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,13]],"date-time":"2026-10-13T17:02:16Z","timestamp":1791910936350,"version":"4.3.4"},"reference-count":45,"publisher":"MDPI AG","issue":"6","license":[{"start":{"date-parts":[[2018,6,6]],"date-time":"2018-06-06T00:00:00Z","timestamp":1528243200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100005416","name":"Research Council of Norway","doi-asserted-by":"publisher","award":["247689"],"award-info":[{"award-number":["247689"]}],"id":[{"id":"10.13039\/501100005416","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["J. Imaging"],"abstract":"<jats:p>Capsule endoscopy, which uses a wireless camera to take images of the digestive tract, is emerging as an alternative to traditional colonoscopy. The diagnostic values of these images depend on the quality of revealed underlying tissue surfaces. In this paper, we consider the problem of enhancing the visibility of detail and shadowed tissue surfaces for capsule endoscopy images. Using concentric circles at each pixel for random walks combined with stochastic sampling, the proposed method enhances the details of vessel and tissue surfaces. The framework decomposes the image into two detailed layers that contain shadowed tissue surfaces and detail features. The target pixel value is recalculated for the smooth layer using similarity of the target pixel to neighboring pixels by weighting against the total gradient variation and intensity differences. In order to evaluate the diagnostic image quality of the proposed method, we used clinical subjective evaluation with a rank order on selected KID image database and compared it to state-of-the-art enhancement methods. The result showed that the proposed method provides a better result in terms of diagnostic image quality and objective quality contrast metrics and structural similarity index.<\/jats:p>","DOI":"10.3390\/jimaging4060075","type":"journal-article","created":{"date-parts":[[2018,6,6]],"date-time":"2018-06-06T07:38:15Z","timestamp":1528270695000},"page":"75","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":16,"title":["Stochastic Capsule Endoscopy Image Enhancement"],"prefix":"10.3390","volume":"4","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-3074-3000","authenticated-orcid":false,"given":"Ahmed","family":"Mohammed","sequence":"first","affiliation":[{"name":"Department of Computer Science, Norwegian University of Science and Technology, 2815 Gj\u00f8vik, Norway"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3473-1138","authenticated-orcid":false,"given":"Ivar","family":"Farup","sequence":"additional","affiliation":[{"name":"Department of Computer Science, Norwegian University of Science and Technology, 2815 Gj\u00f8vik, Norway"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Marius","family":"Pedersen","sequence":"additional","affiliation":[{"name":"Department of Computer Science, Norwegian University of Science and Technology, 2815 Gj\u00f8vik, Norway"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4662-4153","authenticated-orcid":false,"given":"\u00d8istein","family":"Hovde","sequence":"additional","affiliation":[{"name":"Department of Gastroenterology, Innlandet Hospital Trust, Institute of Clinical Medicine, University of Oslo, 0315 Oslo, Norway"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1982-6609","authenticated-orcid":false,"given":"Sule","family":"Yildirim Yayilgan","sequence":"additional","affiliation":[{"name":"Department of Information Security and Communication Technology Norwegian University of Science and Technology, 2815 Gj\u00f8vik, Norway"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2018,6,6]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"E615","DOI":"10.1055\/s-0034-1393063","article-title":"Is virtual chromoendoscopy useful in the evaluation of subtle ulcerative small-bowel lesions detected by video capsule endoscopy?","volume":"3","author":"Negreanu","year":"2015","journal-title":"Endosc. Int. Open"},{"key":"ref_2","doi-asserted-by":"crossref","unstructured":"Sakai, E., Endo, H., Kato, S., Matsuura, T., Tomeno, W., Taniguchi, L., Uchiyama, T., Hata, Y., Yamada, E., and Ohkubo, H. (2012). Capsule endoscopy with flexible spectral imaging color enhancement reduces the bile pigment effect and improves the detectability of small bowel lesions. BMC Gastroenterol., 12.","DOI":"10.1186\/1471-230X-12-83"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"449","DOI":"10.1100\/tsw.2007.99","article-title":"Narrow-band imaging in digestive endoscopy","volume":"7","author":"Lambert","year":"2007","journal-title":"Sci. World J."},{"key":"ref_4","doi-asserted-by":"crossref","unstructured":"Ramaraj, M., Raghavan, S., and Khan, W.A. (2013, January 26\u201328). Homomorphic filtering techniques for WCE image enhancement. Proceedings of the 2013 Computational Intelligence and Computing Research (ICCIC), Enathi, India.","DOI":"10.1109\/ICCIC.2013.6724282"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"1752","DOI":"10.1109\/TCE.2007.4429280","article-title":"Brightness preserving dynamic histogram equalization for image contrast enhancement","volume":"53","author":"Ibrahim","year":"2007","journal-title":"IEEE Trans. Consum. Electr."},{"key":"ref_6","doi-asserted-by":"crossref","unstructured":"Okuhata, H., Nakamura, H., Hara, S., Tsutsui, H., and Onoye, T. (2013, January 3\u20137). Application of the real-time Retinex image enhancement for endoscopic images. Proceedings of the 35th Annual International Conference of the Engineering in Medicine and Biology Society (EMBC), Osaka, Japan.","DOI":"10.1109\/EMBC.2013.6610273"},{"key":"ref_7","doi-asserted-by":"crossref","unstructured":"Provenzi, E. (2017). Computational Color Science: Variational Retinex-Like Methods, John Wiley & Sons.","DOI":"10.1002\/9781119407416"},{"key":"ref_8","doi-asserted-by":"crossref","unstructured":"Gopi, V.P., Palanisamy, P., and Niwas, S.I. (2012). Capsule endoscopic colour image denoising using complex wavelet transform. Wireless Networks and Computational Intelligence, Springer.","DOI":"10.1007\/978-3-642-31686-9_26"},{"key":"ref_9","doi-asserted-by":"crossref","unstructured":"Liu, H., Lu, W.S., and Meng, M.Q.H. (2011, January 23\u201326). De-blurring wireless capsule endoscopy images by total variation minimization. Proceedings of the 2011 IEEE Pacific Rim Conference on Communications, Computers and Signal Processing (PacRim), Victoria, BC, Canada.","DOI":"10.1109\/PACRIM.2011.6032875"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"2419","DOI":"10.1109\/TIP.2009.2028250","article-title":"Fast gradient-based algorithms for constrained total variation image denoising and deblurring problems","volume":"18","author":"Beck","year":"2009","journal-title":"IEEE Trans. Image Process."},{"key":"ref_11","doi-asserted-by":"crossref","unstructured":"Vu, H., Echigo, T., Yagi, K., Okazaki, H., Fujiwara, Y., Yagi, Y., and Arakawa, T. (2011, January 14). Image-Enhanced capsule endoscopy preserving the original color tones. Proceedings of the International MICCAI Workshop on Computational and Clinical Challenges in Abdominal Imaging, Cambridge, MA, USA.","DOI":"10.1007\/978-3-642-28557-8_5"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"3905","DOI":"10.1155\/2015\/607407","article-title":"Color enhancement in endoscopic images using adaptive sigmoid function and space variant color reproduction","volume":"2015","author":"Imtiaz","year":"2015","journal-title":"Comput. Math. Methods Med."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"222","DOI":"10.1016\/j.jvcir.2011.10.002","article-title":"Wireless capsule endoscopy images enhancement via adaptive contrast diffusion","volume":"23","author":"Li","year":"2012","journal-title":"J. Vis. Commun. Image Represent."},{"key":"ref_14","doi-asserted-by":"crossref","unstructured":"Attar, A., Xie, X., Zhang, C., Wang, Z., and Yue, S. (2014, January 26\u201330). Wireless Micro-Ball endoscopic image enhancement using histogram information. Proceedings of the 2014 36th Annual International Conference of the Engineering in Medicine and Biology Society (EMBC), Chicago, IL, USA.","DOI":"10.1109\/EMBC.2014.6944337"},{"key":"ref_15","doi-asserted-by":"crossref","unstructured":"Srivastava, R., Gupta, J., Parthasarthy, H., and Srivastava, S. (2009, January 19\u201321). PDE based unsharp masking, crispening and high boost filtering of digital images. Proceedings of the International Conference on Contemporary Computing, Aachen, Germany.","DOI":"10.1007\/978-3-642-03547-0_2"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"2475","DOI":"10.1109\/TCE.2010.5681130","article-title":"Brightness preserving dynamic fuzzy histogram equalization","volume":"56","author":"Sheet","year":"2010","journal-title":"IEEE Trans. Consum. Electr."},{"key":"ref_17","doi-asserted-by":"crossref","unstructured":"Rukundo, O., Pedersen, M., and Hovde, \u00d8. (2017). Advanced Image Enhancement Method for Distant Vessels and Structures in Capsule Endoscopy. Comput. Math. Methods Med., 2017.","DOI":"10.1155\/2017\/9813165"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"40503-1","DOI":"10.2352\/J.ImagingSci.Technol.2011.55.4.040503","article-title":"Spatio-temporal Retinex-inspired envelope with stochastic sampling: A framework for spatial color algorithms","volume":"55","author":"Farup","year":"2011","journal-title":"J. Imag. Sci. Technol."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"421","DOI":"10.1109\/83.661192","article-title":"Robust anisotropic diffusion","volume":"7","author":"Black","year":"1998","journal-title":"IEEE Trans. Image Process."},{"key":"ref_20","doi-asserted-by":"crossref","unstructured":"Estrada, F.J., Fleet, D.J., and Jepson, A.D. (2009, January 7\u201310). Stochastic Image Denoising. Proceedings of the British Machine Vision Conference, London, UK.","DOI":"10.5244\/C.23.117"},{"key":"ref_21","doi-asserted-by":"crossref","unstructured":"Azzabou, N., Paragios, N., and Guichard, F. (2006). Random Walks, Constrained Multiple Hypothesis Testing and Image Enhancement, Springer.","DOI":"10.1007\/11744023_30"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"147","DOI":"10.1145\/1618452.1618493","article-title":"Edge-preserving multiscale image decomposition based on local extrema","volume":"28","author":"Subr","year":"2009","journal-title":"ACM Trans. Graph."},{"key":"ref_23","doi-asserted-by":"crossref","unstructured":"Wang, Z., Wang, H., Sun, X., and Zheng, X. (2015). An Image Enhancement Method Based on Edge Preserving Random Walk Filter, Springer.","DOI":"10.1007\/978-3-319-22180-9_42"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"629","DOI":"10.1109\/34.56205","article-title":"Scale-space and edge detection using anisotropic diffusion","volume":"12","author":"Perona","year":"1990","journal-title":"IEEE Trans. Patt. Anal. Mach. Intell."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"260","DOI":"10.1109\/TIP.2008.2008070","article-title":"Shearlet-based total variation diffusion for denoising","volume":"18","author":"Easley","year":"2009","journal-title":"IEEE Trans. Image Process."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"466","DOI":"10.1109\/TIP.2003.809017","article-title":"A new iterated two-band diffusion equation: theory and its application","volume":"12","author":"Shih","year":"2003","journal-title":"IEEE Trans. Image Process."},{"key":"ref_27","doi-asserted-by":"crossref","unstructured":"Rajpoot, K., Rajpoot, N., and Noble, J.A. (2008). Discrete Wavelet Diffusion for Image Denoising, Springer.","DOI":"10.1007\/978-3-540-69905-7_3"},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"51","DOI":"10.1145\/1276377.1276441","article-title":"Multiscale shape and detail enhancement from multi-light image collections","volume":"26","author":"Fattal","year":"2007","journal-title":"ACM Trans. Graph."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"67","DOI":"10.1145\/1360612.1360666","article-title":"Edge-preserving decompositions for multi-scale tone and detail manipulation","volume":"27","author":"Farbman","year":"2008","journal-title":"ACM Trans. Graph."},{"key":"ref_30","doi-asserted-by":"crossref","unstructured":"Holm, J., Tastl, I., and Johnson, T. (2006, January 6\u201310). Definition & use of the ISO 12640-3 reference color gamut. Proceedings of the Color and Imaging Conference Society for Imaging Science and Technology, Scottsdale, AZ, USA.","DOI":"10.2352\/CIC.2006.14.1.art00012"},{"key":"ref_31","unstructured":"Koulaouzidis, A., and Iakovidis, D. (2015, January 25\u201329). KID: Towards a Reference Database for Intelligent Capsule Endoscopy. Proceedings of the IEEE Engineering in Medicine and Biology Conference (EMBC), Milan, Italy."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"010502","DOI":"10.1117\/1.2181547","article-title":"Empirical formula for creating error bars for the method of paired comparison","volume":"15","author":"Montag","year":"2006","journal-title":"J. Electr. Imag."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"491","DOI":"10.1016\/j.jvcir.2012.01.008","article-title":"Measuring perceptual contrast in digital images","volume":"23","author":"Simone","year":"2012","journal-title":"J. Vis. Commun. Image Represent."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"600","DOI":"10.1109\/TIP.2003.819861","article-title":"Image quality assessment: from error visibility to structural similarity","volume":"13","author":"Wang","year":"2004","journal-title":"IEEE Trans. Image Process."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"2378","DOI":"10.1109\/TIP.2011.2109730","article-title":"FSIM: A feature similarity index for image quality assessment","volume":"20","author":"Zhang","year":"2011","journal-title":"IEEE Trans. Image Proces."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"1185","DOI":"10.1109\/TIP.2010.2092435","article-title":"Information content weighting for perceptual image quality assessment","volume":"20","author":"Wang","year":"2011","journal-title":"IEEE Trans. Image Process."},{"key":"ref_37","doi-asserted-by":"crossref","unstructured":"Zuiderveld, K. (1994). Contrast limited adaptive histogram equalization. Graphics Gems, Academic Press Inc.","DOI":"10.1016\/B978-0-12-336156-1.50061-6"},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"174","DOI":"10.1145\/2070781.2024208","article-title":"Image smoothing via L 0 gradient minimization","volume":"30","author":"Xu","year":"2011","journal-title":"ACM Trans. Graph."},{"key":"ref_39","unstructured":"Tomasi, C., and Manduchi, R. (1998, January 7). Bilateral filtering for gray and color images. Proceedings of the Sixth International Conference on Computer Vision, Bombay, India."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"148","DOI":"10.5946\/ce.2017.030","article-title":"Quality indicators for small bowel capsule endoscopy","volume":"50","author":"Shim","year":"2017","journal-title":"Clin. Endosc."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"1133","DOI":"10.3109\/00365521.2011.584899","article-title":"Improved detectability of small-bowel lesions via capsule endoscopy with computed virtual chromoendoscopy: a pilot study","volume":"46","author":"Imagawa","year":"2011","journal-title":"Scand. J. Gastroenterol."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"218","DOI":"10.5009\/gnl.2012.6.2.218","article-title":"Role of enhanced visibility in evaluating polyposis syndromes using a newly developed contrast image capsule endoscope","volume":"6","author":"Hatogai","year":"2012","journal-title":"Gut liver"},{"key":"ref_43","unstructured":"Xu, L., Ren, J., Yan, Q., Liao, R., and Jia, J. (2015, January 6\u201311). Deep edge-aware filters. Proceedings of the 32nd International Conference on Machine Learning, Lille, France."},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"792","DOI":"10.1016\/j.asoc.2016.01.003","article-title":"Image smoothing with generalized random walks: Algorithm and applications","volume":"46","author":"Wang","year":"2016","journal-title":"Appl. Soft Comput."},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"1768","DOI":"10.1109\/TPAMI.2006.233","article-title":"Random walks for image segmentation","volume":"28","author":"Grady","year":"2006","journal-title":"IEEE Trans. Patt. Anal. Mach. Intell."}],"container-title":["Journal of Imaging"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2313-433X\/4\/6\/75\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T15:07:32Z","timestamp":1760195252000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2313-433X\/4\/6\/75"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2018,6,6]]},"references-count":45,"journal-issue":{"issue":"6","published-online":{"date-parts":[[2018,6]]}},"alternative-id":["jimaging4060075"],"URL":"https:\/\/doi.org\/10.3390\/jimaging4060075","relation":{"has-preprint":[{"id-type":"doi","id":"10.20944\/preprints201804.0333.v2","asserted-by":"object"},{"id-type":"doi","id":"10.20944\/preprints201804.0333.v1","asserted-by":"object"}]},"ISSN":["2313-433X"],"issn-type":[{"value":"2313-433X","type":"electronic"}],"subject":[],"published":{"date-parts":[[2018,6,6]]}}}