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I'm am aware that the filter/other/hsl-hsb filter can be used to turn the red channel into one representing the hue (on a grey scale 0-255).
But what I would realy like, as a diagnostics tool, is a method that will convert a color image into one where both saturation and lightness/brightness are stadardised for all pixels (to e.g. 50%), so that the resulting images reflects only the variations in hue across the image.
Any suggestions?
BR
Karsten
#huemap
Thanks Dave, I think this will do the trick for me - and also thanks for making me aware of the caveat 🙂
BR Karsten
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You could try something like this :
Add a colour fill layer set to S = 50 (the H and B do not matter)
Add a second colour fill layer set to Luminosity 50 (or whatever you want as standard) in Lab then set Blend mode to Luminosity
Finally add your image with Blend mode set to Hue
The issue will be that where saturation is zero, so a perfect grey, the Hue could be any value at all as it is not used. So I'm not sure of the value in doing this.
Dave
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Thanks Dave, I think this will do the trick for me - and also thanks for making me aware of the caveat 🙂
BR Karsten
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Since, in Lab Color:
Lightness is separate from Color and the color channels control Saturation,
you may also consider doing all the work in Curves, on a single layer in that Mode. The method takes longer to describe than to execute.
First, though, after changing the file’s mode to Lab Color and choosing Image> Adjustments> Curves, it is recommended that you change the grid to 10x10 and choose Pigment/Ink% (so that the scales run from light to dark, rather than from dark to light).
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Thanks Norman, definately an interesting approach, and thanks for the clear and careful explanation 🙂
BR Karsten