We treat the tag prediction task as a multi-label classification task.
given an image I, we first extract its features {v n } N n=1 ∈ R D from an intermediate layer of a CNN, and then feed {v n } N n=1 into a multi-label classification (MLC) network to generate a distribution over all of the L tags: where l ∈ R L is a tag vector, l i = 1/0 denote the presence and absence of the i-th tag respectively, and MLC i means the i-th output of the MLC network.