Equations/Details of the Color Transformations

[tmanni]

As far as I know, there is no "mathematical" documentation of the algorithms. But If reading the C code don't scare you, it's available online.
For gimp tools (like brightness-contrast, color balance) it's here :

https://gitlab.gnome.org/GNOME/gimp/-/tr...operations

For other filters (GEGL operations) it's here:

https://gitlab.gnome.org/GNOME/gegl/-/tr...operations