Bag-Based Classification Methods

In bag-based multi-instance methods, the main learning process occurs at the level of bags. In this chapter, we analyze two important subcategories of bag-based MIL classifiers. On the one hand, in Sect. 5.2, we examine classifiers that define a distance or similarity measure between bags to work directly in the original bag space. On the other hand, Sect. 5.3 is devoted to mapping-based classifiers that transform each bag to a single-instance representation such that the learner can train any single-instance classifier to label new bags.