1. A method performed by a computing system comprising a processor and a memory, for identifying tissue structures in a microscope image of a tissue sample, the method comprising: preparing a histology slide comprising a tissue sample, including staining the tissue sample with haematoxylin and eosin; receiving digitized microscope image data from a microscope defining a microscope slide image of the haematoxylin and eosin stained tissue sample, wherein the digitized microscope slide image data comprises a plurality of image pixels; receiving digitized descriptor data indicating a type of tissue from which the tissue sample originates, the descriptor data comprising a machine-readable identifier of tissue type; using the descriptor data, selecting from data stored in the computer memory an image operation configured to transform the digitized image data; transforming the digitized image data, using the selected image operation to obtain a transformed image and identifying a number of discrete spatial regions of the digitized image, wherein said transformed image can be obtained by intensity transformation, morphological transformation or histogram equalization; selecting, from data stored in the computer memory, a set of quantitative image metrics based on the descriptor data, computing, for each identified discrete spatial region, a sample region data value for each of the set of quantitative image metrics based on the subset of image data associated with each discrete spatial region, using the descriptor data, selecting from data stored in the computer memory, at least one comparator set comprising tissue model data values, wherein each comparator set is associated with a different tissue structure, and each comparator set comprises data values of a set of quantitative image metrics for the associated tissue structure; comparing the sample region data value for each discrete spatial region with the at least one comparator set; and where the sample region data value for each discrete spatial region matches the comparator set, providing a map of the image data indicating that the discrete spatial region comprises the matching comparator tissue structure.