1. A method for generating a superpixel cluster for an image, the method comprising: generating an initial cluster of superpixels from an initial cluster center; determining, within said initial cluster, one or more further cluster centers different from said initial cluster center; generating one or more further clusters of superpixels from the one or more further cluster centers; and grouping the superpixels of the initial cluster with the superpixels of the one or more further superpixel clusters to obtain the superpixel cluster for the image.