I have extracted faces from a video and I clustered them in big groups (each group contains faces from the same person, I did this using change of background detection). Now I want to cluster those groups into a smaller number of groups and to have, at the end, one cluster per person appearing in the video.
At the moment I managed to cluster those groups using histograms of colors and K-means. The problem is that when skin and hair color are too close for two different people, the clusters are bad. Which other features can I use for this? I tried DAISY descriptors but the results were not interesting. Also I would like to make those clusters without having to specify the number of clusters I want to have at the end.