Cartoon of XRF discovery of hidden van Gogh painting

Cartoon of a scanning XRF experiment to investigate a hidden painting by van Gogh of the head of a peasant woman under the known painting “Patch of Grass” (1887). The program uses the function colormix from the Matlab File Exchange at https://ch.mathworks.com/matlabcentral/fileexchange/41595-colormix. Acknowledgements go to the enigmatically named “Jurgen” for this. The program uses five image files which are downloadable below. For more information about the original experiment, see: article by Dik et al., http://doi.org/10.1021/ac800965g).