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PART|II Multimodal Signal Processing and Modelling
to the ease of accessing and processing match scores (compared
to the raw data or the feature set extracted from the data). Fusion
methods at this level can be broadly classified into three cate-
gories [1]: density-based schemes [23,24] (generative approach),
classifier-based schemes (discriminative approach) [25] and
transformation-based schemes [26] (see also Section 8.4).
4. Rank-level fusion: In HCI applications, the output of the system
can be viewed as a ranking of plausible hypotheses. In other
words, the output indicates the set of possible hypotheses sorted
in decreasing order of confidence. ...