Figure 6
From: Automatic multiple zebrafish tracking based on improved HOG features

Initial tracklets selection to train the classifier. Assuming that the tracklets disconnected on frame t, each colourful tracklet belongs to one identity, and the black tracklets denote the tracklets with unclear identities. The tracklet group before the crossing is denoted as A and the group after the crossing is denoted as B. There are 3 identities in each group. Group A is selected as the training set, and group B serves as the test set as min(NF)A> min(NF)B.