1. A computer system comprising: one or more processors; one or more non-transitory computer-readable storage media storing instructions which, when executed using the one or more processors, cause the one or more processors to perform: receiving a first plurality of images of a first type; receiving a second plurality of images of a second type; generating a feature set dictionary comprising mappings from features of the first plurality of images to features of the second plurality of images; receiving a first particular image of the first type; generating a second particular image of the second type using the first particular image and the feature set dictionary.