Nearest neighbor techniques representation

K-nearest neighbors (KNN) is the name of a classification method that is unsupervised in the sense that class membership is not used to train the technique, but that makes predictions of class membership. The principle behind KNN is an appealingly common sense one objects that are close together in the descriptor space are expected to show similar behavior in their response. Figure 7.5 shows a two-dimensional representation of the way that KNN operates. 

Temporal-independent techniques neglect the information in the temporal domain. They summarize all of the frames for an observed sequence into a single representation, subsequently performing activity recognition for each frame. The main techniques in this category include fc-nearest neighbors (KNN) and support vector machines (SVMs). 

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