1. A method, comprising: applying a first stain to a first sample having a plurality of regions, wherein the first stain selectively binds to only a first subset of the regions of the first sample; applying a second stain to the first sample, wherein the second stain binds to a second set of regions of the first sample; obtaining an image of the first sample, and analyzing the image to obtain a first component image corresponding substantially only to spectral contributions from the first stain, and a second component image corresponding substantially only to spectral contributions from the second stain; and training a classifier to identify regions of a second sample based on information derived from the first and second component images, the identified regions corresponding to the first subset of regions of the first sample.