1. A method for generating thumbnail images from video signals, comprising: receiving a sequence of images in an input video signal; detecting a subset of images each depicting one or more character faces in the sequence of images; applying one or more auto clustering algorithms to the subset of images to generate a plurality of image clusters; determining a cluster distance for each image in each image cluster in the plurality of image clusters; determining a quality metric for each image in each image cluster in the plurality of image clusters; assigning a weighted score to each image in each image cluster in the plurality of image clusters, based on an individual cluster distance for each such image and an individual quality metric for each such image; based on an individual weighted score for each image in each image cluster in the plurality of image clusters, selecting a subset of image clusters from the plurality of image clusters; causing one or more thumbnail images generated from one or more images in the subset of image clusters to be rendered on a display device to a viewer.