Character Identification in TV-series via Non-local Cost Aggregation.

We propose a non-local cost aggregation algorithm to recognize the identity of face and person tracks in a TV-series. In our approach, the fundamental element for identification is a track node, which is built on top of face and person tracks. Track nodes with temporal dependency are grouped into a knot. These knots then serve as the basic units in the construction of a k-knot graph for exploring the video structure. We build the minimum-distance spanning tree (MST) from the k-knot graph such that track nodes of similar appearance are adjacent to each other in MST. Non-local cost aggregation is performed on MST, which ensures information from face and person tracks is utilized as a whole to improve the identification performance. The identification task is performed by minimizing the cost of each knot, which takes into account the unique presence of a subject in a venue. Experimental results demonstrate the effectiveness of our method.