jaanco66

I have four separate feature requests that I'd like to submit. I have created a separate post for each of them, and they are all posted here within the "Feature Requests & Feedback" section. I have included proposed Studio-type panels (or modifications of existing panels) in each of the posts.
3) Select Color Range using HSL-like Definition
I love that the HSL Adjustment panel now allows customized hue ranges. It's a really powerful addition. I would really like to see this sort of color range choice for some variant of the Select Color Range… menu choice. In addition to Select Reds, Select Greens, and Select Blues, I would love to be able to choose Select Custom… and be presented with the same color range chooser used in the HSL panel. The output of such a Select Custom… choice should be tailored in a similar fashion to the Refine Selection dialog; that is, allow the output to be a Selection, a Mask, a Layer, or a Layer with a Mask.

Hey, John and R C-R...
First of all, the link to that series of posts is:  https://forum.affinity.serif.com/index.php?/topic/76900-saturation-masks-a-simple-method/
Second, Apply Image really only needs a single image (in fact, a single layer) since there is a button near the top of the dialog box that says "Use Current Layer as Source." Clicking that lets you apply the layer to itself. Here is a screen shot where I swapped the Red and Green channels in a photo (original on the left, swapped channels on the right).

The more important point might be that your last question is easier to answer than Dave Straker's math makes it out to be. I have posted a series of macros which will (i) create Saturation masks and Vibrance masks (inverted Saturation masks); (ii) create greyscale visualization layers for those masks; and (iii) allow you to apply the masks to a layer stack. You can access those macros here: https://forum.affinity.serif.com/index.php?/topic/87004-macro-updates-for-v17/