1. An apparatus for imaging a biological sample, comprising: an input configured to receive at least one of imaging data acquired from and an image of the biological sample; and a processor configured to receive the at least one of the imaging data and the image from the input, enhance spectral signals associated with the at least one of the imaging data and the image, and apply a linear transform using estimated transmission data and training data to generate a representation of a reaction of the biological sample to a target chemical stain.