Direct Component Selector

The YOUTUBE tutorial can be found HERE.

Highly developed approaches can be unsatisfying and a direct approach may be preferred. The tool is a simple interactive endmember selection tool.
If one clicks once on a pixel in the SAM window its spectrum is shown in the Spectra window. If one double clicks on it, it is selected as an endmember and added to the table in the main window. At the same time the pixels associated to it based on spectral angle are calculated. The spectral range for this is selected in the lowest button row of the Main widget. There also the maximum spectral angle of the endmember can be selected here. In the histogram window the solid line shows the cosine distance of all pixels to the selected endmember(s). The dashed line only that not associated with another endmember.
“SaveImages” saves the current content of the plot windows.
The second row from the bottom decides on the properties of the Spectra window, i.e. If endmembers or average spectra are shown, if the legend is shown and if correct units or channel numbers are used.
In the row above mostly the display in the SAM window is edited, i.e. if the RGB image and the Rule image are shown or not or if the RGB image should be replaced by one with optimized contrast. The crosses indicate the location of the endmembers.
The Checkbox “Auto Compute” decides if the SAM map is recalculated once any parameter is changed or not. Especially for large data sets the GUI is slowed down strongly, if this option is selected. If the box is un-checked the “Compute Rule” button enforces a single calculation of the SAM.
In the top row of buttons one can, beside forcing a SAM computation, “Load” a raw data set, “Del”ete the selected endmembers, but also load Endmembers from an external file. One can save the results and select the color for the selected endmembers.

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This tool was devloped for verfying the data published below, to which should be referred when the tool is used.
Reference: L. de Viguerie, S. Rochut, M. Alfeld, P. Walter, S. Astier, V. Gontero, F. Boulc’h, "XRF and reflectance hyperspectral imaging on a 15th century illuminated manuscript: combining imaging and quantitative analysis to understand the artist’s technique" , Herit. Sci. 6 (2018) 11. https://doi.org/10.1186/s40494-018-0177-2.