Figure 3

Color mapping of spectral features in a baseline-corrected image. Labels indicate peaks representing prominent chemical features. (a) The spectral histogram shows a rainbow color map applied based on the peak height of the Amide I band (vertical white line). The peak height of Amide I is often assumed to correspond to tissue thickness and density in tissue samples. Note how the colors mix as individual spectra cross and overlap with changes in density and chemistry. Spatial images show the result of a (b) Gaussian and (c) linear ramp applied to the lasso.