Re: [Gimp-developer] deriving transform by comparing image before/after edit

[Liam R E Quin <liam holoweb net>]

On Mon, 2020-12-28 at 10:21 +0100, Adalbert Hanßen via gimp-developer-
list wrote:
> Bill,
>
> unfortunately the result of a convolution operation can not always be
> inverted. 

It turns out that inversion is not needed. In cases like the example
shown, colour grading was probably all that was done (i didn't check
carefully). The term "matrix" in the post was i think perhaps not to be
taken literally.

For colour mapping/grading, there's a plugin included in gimp i think
that will take the colour from  one layer and apply it to another,
which might go a long way. And i think Produkine mentioned a script 
someone wrote that tries to deduce a set of curves for colour/levels.

Many other transformations are much harder or even impossible, as
Adalbert states.

> Try my background removal operation with the appended example file,

Attachments do not get passed through the mailing list.


liam


-- 
Liam Quin - web slave for https://www.fromoldbooks.org/

full-time slave in voluntary servitude