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An efficient retinex-like brightness normalization method for coding camera flashes and strong brightness variation in videos / Hoi-Kok Cheung in Signal processing. Image communication, Vol. 25 N° 3 (02 ex.) (Mars 2010) 

Public ISBD [article]  in Signal processing. Image communication > Vol. 25 N° 3 (02 ex.) (Mars 2010) . - pp. 143–162 Titre : An efficient retinex-like brightness normalization method for coding camera flashes and strong brightness variation in videos Type de document : texte imprimé Auteurs : Hoi-Kok Cheung, Auteur ; Wan-Chi Siu, Auteur ; Dagan Feng, Auteur Année de publication : 2010 Article en page(s) : pp. 143–162 Note générale : Electronique Langues : Anglais (eng) Mots-clés : Video  coding  Motion  estimation  Brightness  variation  Retinex  image Index. décimale : 621.382 Dispositifs électroniques utilisant les effets des corps solides. Dispositifs semi-conducteurs Résumé : Conventional hybrid video coding systems rely on the assumption that the brightness is constant. This does not take inter-frame brightness variations into consideration during motion estimation and compensation processes. Under the influence of inter-frame lighting variations like camera flashes, video motion activities are not accurately estimated and the pixel prediction is poor which directly increases the bits for prediction error coding. In this paper, we propose an efficient algorithm based on the retinex-like system which allows inter-frame brightness being normalized before applying the conventional motion estimation and compensation. Experimental results show that our approach is superior to all similar approaches in the literature and demonstrate that our proposed system is very robust against the inter-frame brightness variations. Further experimental works have been done using the verification models of the MPEG-4 and the H.264 on sequences with brightness variations, results of which show that our proposed system outperforms these coding systems, including the weighted prediction feature in H.264, which were specifically designed for this purpose. DEWEY : 361.382 ISSN : 0923-5965 En ligne : http://www.sciencedirect.com/science/article/pii/S0923596510000020 [article] An efficient retinex-like brightness normalization method for coding camera flashes and strong brightness variation in videos [texte imprimé] / Hoi-Kok Cheung, Auteur ; Wan-Chi Siu, Auteur ; Dagan Feng, Auteur . - 2010 . - pp. 143–162. Electronique Langues : Anglais (eng) in Signal processing. Image communication > Vol. 25 N° 3 (02 ex.) (Mars 2010) . - pp. 143–162 Mots-clés : Video  coding  Motion  estimation  Brightness  variation  Retinex  image Index. décimale : 621.382 Dispositifs électroniques utilisant les effets des corps solides. Dispositifs semi-conducteurs Résumé : Conventional hybrid video coding systems rely on the assumption that the brightness is constant. This does not take inter-frame brightness variations into consideration during motion estimation and compensation processes. Under the influence of inter-frame lighting variations like camera flashes, video motion activities are not accurately estimated and the pixel prediction is poor which directly increases the bits for prediction error coding. In this paper, we propose an efficient algorithm based on the retinex-like system which allows inter-frame brightness being normalized before applying the conventional motion estimation and compensation. Experimental results show that our approach is superior to all similar approaches in the literature and demonstrate that our proposed system is very robust against the inter-frame brightness variations. Further experimental works have been done using the verification models of the MPEG-4 and the H.264 on sequences with brightness variations, results of which show that our proposed system outperforms these coding systems, including the weighted prediction feature in H.264, which were specifically designed for this purpose. DEWEY : 361.382 ISSN : 0923-5965 En ligne : http://www.sciencedirect.com/science/article/pii/S0923596510000020