I have used larch some for XRF maps. I like the feature for defining ROI's and then looking at the statistics of the data. I have some samples that are an intimate mix of two or more phases and I would like to extract pixels based on a criteria- like high Sr or low Fe, etc, from across a whole map region. I wonder if this feature is available, or would be easy to create on larch?
Like you say, this is not currently available in the Mapviewer GUI. But it's a good suggestion and might be possible to do with a small amount of code.
Would it work for you to say "Make an Area with all pixels where Sr Counts is above some value"? I think that would be easy to generalize from "Sr Counts" to
"Ratio of ROI Counts" (or "analyzed concentration" once I get that done - a work in progress). If that's right, I think it would be "not hard to add".
--Matt