Abstract

The multimodal information can be assimilated at three levels 1) early fusion, 2) intermediate fusion, and 3) late fusion. Early fusion can be performed at the sensor or signal level. Intermediate fusion can be at the feature level, and late fusion may be done at the decision level. Apart from that, some more fusion techniques are rank-based, adaptive, etc. This chapter provides an extensive review of studies based on fusion and reported noticeable work herewith. Eventually, we discussed the challenges associated with multimodal fusion.