1. A computer-implemented method comprising: obtaining an image query, the image query being a query for image search results; obtaining ranked image search results responsive to the image query, the image search results each including an identification of a corresponding image resource; generating a similarity matrix for images identified by the image search results; generating a hierarchical grouping of the images using the similarity matrix; identifying a canonical image for each of a plurality of groups in the hierarchical grouping using a ranking measure; and providing a visual representation of the image search results based on the hierarchical grouping and the identified canonical images using a representation of one or more of the identified canonical images to represent one or more corresponding groups of images in the visual representation, and wherein the visual representation includes one or more first canonical images having a first size representing higher level image clusters and one or more second canonical images having a second smaller size and each second canonical image being associated with a respective first canonical image.