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Multimedia Information Retrieval (MMIR or MIR) is a research discipline of computer science that aims at extracting semantic information from multimedia data sources.〔H Eidenberger. " Fundamental Media Understanding ", atpress, 2011, p. 1.〕 Data sources include directly perceivable media such as audio, image and video, indirectly perceivable sources such as text, biosignals as well as not perceivable sources such as bioinformation, stock prices, etc. The methodology of MMIR can be organized in three groups: # Methods for the summarization of media content (feature extraction). The result of feature extraction is a description. # Methods for the filtering of media descriptions (for example, elimination of redundancy) # Methods for the categorization of media descriptions into classes. == Feature Extraction Methods == Feature extraction is motivated by the sheer size of multimedia objects as well as their redundancy and, possibly, noisiness.〔H Eidenberger. " Fundamental Media Understanding ", atpress, 2011, p. 2.〕 Generally, two possible goals can be achieved by feature extraction: * Summarization of media content. Methods for summarization include in the audio domain, for example, Mel Frequency Cepstral Coefficients, Zero Crossings Rate, Short-Time Energy. In the visual domain, color histograms〔A Del Bimbo. " Visual Information Retrieval ", Morgan Kaufmann, 1999.〕 such as the MPEG-7 Scalable Color Descriptor can be used for summarization. * Detection of patterns by auto-correlation and/or cross-correlation. Patterns are recurring media chunks that can either be detected by comparing chunks over the media dimensions (time, space, etc.) or comparing media chunks to templates (e.g. face templates, phrases). Typical methods include Linear Predictive Coding in the audio/biosignal domain,〔HG Kim , N Moreau, T Sikora. " MPEG-7 Audio and Beyond", Wiley, 2005.〕 texture description in the visual domain and n-grams in text information retrieval. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Multimedia Information Retrieval」の詳細全文を読む スポンサード リンク
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