1. A method comprising: identifying, by one or more processors, a caption associated with an image included in a document in a cluster of documents; generating, by one or more processors, a first score for the image based on a size of the image; generating, by the one or more processors, a second score for the image based on a distance between the image and a title of the document; generating, by the one or more processors, a third score for the image based on the caption associated with the image; generating, by the one or more processors, an overall score for the image based on the first score, the second score, and the third score; identifying, by one or more processors, the image for being representative of the cluster based on the overall score; and associating, by one or more processors, the image with the cluster as being a representative image of the cluster.