1. A method for processing images, the method comprising using a processing module in a computer system for: identifying clusters of first features identified in a first image, wherein each cluster in the clusters comprises a first group of features from the first features; identifying a transformation for registering each cluster in the clusters with a corresponding cluster comprising a second group of features from second features identified in a second image using an initial correspondence between the first features in the first image and the second features in the second image; identifying a set of clusters from the clusters of the first features using the transformation identified for each cluster; adding a cluster in the clusters to the set of clusters when a projection error for the transformation identified for the cluster is less than a selected threshold; and identifying a final transformation for registering the first image with the second image using the set of clusters.