Was using this image for a bit of troubleshooting some DT issues (editing look vs exported look) and it cleaned up quite quickly and nicely. Figure I let everyone else have some fun with it.
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Looks like radar interferometry 
DSC07825_01.ARW.xmp (16,5 KB)
DSC07825.ARW.xmp (17.1 KB)
Yep, I’ve never understood the meaning of the RGB settings “Frequency” and “Phase Shift” as they relate to the slider positions
Even less in the HSL option
DSC07825.ARW.arp (13.7 KB)
DSC07825.ARW.xmp (20.7 KB)
DT 5.1 nice capture made my job easy.
DSC07825.ARW.xmp (20.6 KB)
And I still can’t help myself. Only a few days before I return to the grind. Nice to be able to play without having to think I will have to go to work the next day. lol
Finally got that after considerable research:
new_value = 0.5 + 0.5 * sin(frequency * (2Ď€ * v / 255) + phase)
Where v = the channel level 0-255 on the map x-axis and Frequency (GIMP) is 0-20.
So three tone maps are used - one for each channel where the Frequency tone-to-tone transfer characteristic is sinusoidal not just a simple curve and the Phase moves the sinusoid from side-to-side.
