In conventional x-ray mapping, energy regions are defined to straddle the N x-ray spectral peaks of interest. At each pixel position in the digital image, counts are recorded from each energy region and thus give rise to N element maps of intensity distributions over the field of view. Fig. 1 shows an example set of x-ray maps from a polished test sample. It is clear from the images that there are circular regions of differing composition but it is not immediately obvious which regions have the same composition. Furthermore, in a real sample, phases are unlikely to appear in such regular patterns so the correlations between maps are in general much more difficult to notice.

It is possible to choose two x-ray maps and generate a 2D scatter plot showing the intensity values in both maps for all pixels in the image.