Wednesday, January 13, 2021

Ofn Luminosity Masks Ver.1.3

 Ofn Luminosity Masks []

Author: Ofnuts
In menu:  

Select / Luminosity / Custom / Sample curve
Select / Luminosity / Raw luminosity
Select / Luminosity / Patdavid / Lights / L
Select / Luminosity / Patdavid / Lights / LL
Select / Luminosity / Patdavid / Lights / LLL
Select / Luminosity / Patdavid / Darks / D
Select / Luminosity / Patdavid / Darks / DD
Select / Luminosity / Patdavid / Darks / DDD
Select / Luminosity / Patdavid / MidTones / M
Select / Luminosity / Patdavid / MidTones / MM
Select / Luminosity / Patdavid / MidTones / MMM

Website author here.

The rules of use are contained in the files Doc - just a fragment here:


This plug-in creates a selection mask based on the luminosity of pixels.

These selection masks are called "Luminosity masks" and are a very powerful technique to perform smooth and natural color changes in a picture. This technique is very well explained in PatDavid's canonical tutorial on the subject.

This plug-in creates the masks shown in the tutorial, among others

Unlike the tutorial, and unlike most Gimp scripts based on this tutorial,

  • The script creates only one mask at a time.
  • The mask is not created by addition/composition of other masks, but by applying directly the equivalent curve with the Curves tool.
  • The script creates a mask using the current state of the layer. The tutorial and the scripts create all the masks once, usually on the initial state of the image, so when the masks are used successively, the pixels remain selected based on their initial luminosity and not on the luminosity they reached following the previous edits (unless you redo all the masks of course).

A side benefit of the single-mask approach is that the selection can be automatically set from the mask and this saves a few mouse clicks."....


 Image created by Ofnuts.

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