04-17-2024, 04:12 PM
(04-17-2024, 03:06 PM)rich2005 Wrote: It would still be beneficial for a clip from your problem image, 16 bit grayscale in Gimp .xcf format. The forum has a 2 MB file size limit.
However, this might work (or not) with your large image, it will consume a lot of resources.
This is a 30 second animation of the sequence. https://i.imgur.com/nlSe0rA.mp4
I have base layer (your image) which contains 2 areas of just-off pure black sp1 hex 000002 and sp2 hex 000004
Add this to a layer group and put a black layer over it and change the layer mode to divide.
Now in the layer group colour select the black. That is your selection, delete the black layer, merge the layer group.
So I have uploaded a small area from the whole.
But when I put the Black layer in Divide mode it goes a bit weird, or at least not the same as what I expected.
It might be the notation throwing me, so I am trying to select up to RGB(1.0,1.0,1.0) and lessor shade down to 0, which seems to equate to hex 030303.
Did I get that right?