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+--- Thread: ofn-luminosity-masks (/Thread-ofn-luminosity-masks)
RE: ofn-luminosity-masks - Ofnuts - 11-16-2019
(11-16-2019, 11:09 PM)Krikor Wrote:(11-16-2019, 06:14 PM)Ofnuts Wrote: Uploaded a new version. Added feature; define your own mask(s) in a side file. Enjoy.
Ofnuts,
But what if the curve also has points on other RGB channels?
The image shows the configuration of my curve. If I only use the values from line # 9 after Points 34, would it be enough for the mask to represent the curve?
The curve applies to a channel, so normally to a grayscale image with a single channel.
A possible technique
- Create the "L" selection
- In the channels list:
- Add a channel, tick the "initialize from selection" (this works arounf the current bug on channels)
- Select the channel and make it visible
- Make sure the original L channel is not visible and not selected
- Add a channel, tick the "initialize from selection" (this works arounf the current bug on channels)
- In the image Window, start the Curves tool, it applies to the channel
- Adjust the curve so that the parts you are interested in remain visible (the rest turns white)
- Apply the curve and make a test
RE: ofn-luminosity-masks - Blighty - 11-17-2019
Thanks Ofnuts
I made a DDDD, useful for lifting shadows.
Very quick and easy (once I had read the docs on how to refresh the ini).
RE: ofn-luminosity-masks - Krikor - 11-17-2019
(11-16-2019, 11:59 PM)Ofnuts Wrote: The curve applies to a channel, so normally to a grayscale image with a single channel.
A possible technique
- Create the "L" selection
- In the channels list:
- Add a channel, tick the "initialize from selection" (this works arounf the current bug on channels)
- Select the channel and make it visible
- Make sure the original L channel is not visible and not selected
- In the image Window, start the Curves tool, it applies to the channel
- Adjust the curve so that the parts you are interested in remain visible (the rest turns white)
- Apply the curve and make a test
I followed the steps above, and ok, but give the same result I had already displayed at https://www.gimp-forum.net/Thread-ofn-luminosity-masks?pid=15576#pid15576
I was trying something impossible a priori.
I should know that masks and channels only work with the Value channel.
It took me a while to understand why my curve generates a mask that is virtually identical to the L-mask (PatDavid-Lights-L).
BTW I learned a lot of new things by following the steps above, Thx Ofnuts.
RE: ofn-luminosity-masks - Ofnuts - 11-19-2019
Small update, mostly to the documentation. Added a "Raw luminosity" mask (identical to L, but L could change later).
The doc explains how to create your mask and curve from the quickmask.
RE: ofn-luminosity-masks - Krikor - 11-19-2019
The script lets you use curves to create our own masks.
But ... would it be possible to create my own masks using the channels I created?
Is there a way to create curves of the desired channels?
Channels Created
RE: ofn-luminosity-masks - Ofnuts - 11-19-2019
Yes, but it's going to be a bit manual:
- Copy the channel to a layer, scale to 1000px wide
- Take out the pointer dialog, set one coilumn to RGB(%)
- Move your mouse across the layer see where the change points are (with the pointer dialog you can easily tell where/when you hit 0% or 100%.
- Divide x by 1000 to get the X coordinate, and by 100 any of the RGB value to get the Y coordinate, and add to the curve.
RE: ofn-luminosity-masks - Krikor - 11-19-2019
(11-19-2019, 05:40 PM)Ofnuts Wrote: Yes, but it's going to be a bit manual:
- Copy the channel to a layer, scale to 1000px wide
- Take out the pointer dialog, set one coilumn to RGB(%)
- Move your mouse across the layer see where the change points are (with the pointer dialog you can easily tell where/when you hit 0% or 100%.
- Divide x by 1000 to get the X coordinate, and by 100 any of the RGB value to get the Y coordinate, and add to the curve.
In Portuguese, we say "this is not my beach" when we are dealing with something that is unfamiliar to us. A bit like "A fish out of water".
But voilà my doubt.
To try to understand better, I used the coordinates of the existing DD and L masks.
DD = 0.00 1.00 0.50 0.00 1.00 0.00
L = 0.00 0.00 1.00 1.00
For the DD copy I found:
X = 0 at 0% at the extreme left point;
X = 500 at 0%;
X = 1000 by 100%
What I would create generating points 0.00 0.00 0.50 00 1.00 1.00 (but as seen above in bold is not the case)
For copy L I found:
x = 0 at 100% first point left;
x = 1000 at 0%.
I would then have: 0.00 1.00 1.00 0.00 (equally different from the expected 0.00 0.00 1.00 1.00).
What am I failing to understand?
Thx.
RE: ofn-luminosity-masks - Ofnuts - 11-19-2019
I think you are looking at them in the wrong direction.
- The input is dark to light from left to right (like in Curves or Levels)
- The output "whiteness" indicates selection: black is no selection, white is full selection.
RE: ofn-luminosity-masks - Krikor - 11-20-2019
(11-19-2019, 05:40 PM)Ofnuts Wrote: - Move your mouse across the layer see where the change points are (with the pointer dialog you can easily tell where/when you hit 0% or 100%.
- Divide x by 1000 to get the X coordinate, and by 100 any of the RGB value to get the Y coordinate, and add to the curve.
By following these steps, I was able to reproduce the points for the MMM channel.
But for L and DD channels (possibly for others too) it doesn't work.
The 1000x scaled image from the L channel to the points where X changes.
https://imgur.com/a/Kf5nTxv
RE: ofn-luminosity-masks - Ofnuts - 11-20-2019
What you are showing is not the L mask but the D mask. The L mask has the white on the right. See my previous answer.