スポーツ映像からのコミック風コマ割りダイジェスト画像の 自動生成

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Vol.2012-DCC-1 No.15
2012/5/18
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Automatic Generation of an Image Digest with a Comic-like Layout
from a Sports Video
SHINJI MIZUNO† TOMOYUKI USUGI††
A digest of a long sports match video is useful to catch the progress of the match in a short time. Video digests which include
important scenes are often used in sports news programs. However, image digests are useful in sports papers and web pages. In
this paper, we propose a method to generate an image digest from a sports match video. An image digest generated by our
method has a comic-like layout, and it is easy to catch the progress of the match from the image digest intuitively. The process of
the proposed method is extracting important scenes, generating images which represent the scenes, and arranging the images in a
comic-like layout. We use videos from soccer TV programs in experiments and evaluate our method.
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1) ƹŎǝ», {ƧƔ, Á‘þ, ìĶ‘: ĕŠMwu&ƨĹ"W
sUcĈÓ;ţǖŠ}ƉS@NBOYś&Ɨ­ŢďŐ, Ī•
ĈÓkX?>ã‰ēƟÓÅ, 28(71), pp. 27-30 (2004).
2) éïƜÄ, ÜǛÈÝ: LUFw­Ť%
7Ť•žš%47
]@o@YŢď, Ī•ĈÓkX?>ã‰ēƟÓÅ, 35(8), pp. 17-19
(2011).
3) Myodo, E., Ueno, S., Takagi, K., Sakazawa, S.: Automatic
Comic-like Image Layout System Preserving Image Order and
Important Region, Proc. of the 19th ACM International Conference on
Multimedia, pp. 795-796 (2011).
4) Calic, J., Gibson, D.P., Campbell, N.W.: "Efficient Layout of
Comic-like Video Summaries", IEEE Transactions on Circuits and
Systems for Video Technology, Vol. 17, No. 7, pp. 931-936 (2007).
5) ǘÎĬı, éŇâĥ, ƹ¹®Ɛ: ǂùÙ¯&²ƴć%ŲŬ
XQqbĿŸđŐ, ǡßĈÓNJ‘ã‰Ƌ¿Ü‰ƶŗƵĥǠ,1996
÷, ĈÓvMOWj(2), p. 403 (1996).
2012 Information Processing Society of Japan
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