Script-fu How Write Colors-Auto-White Balance

[James Parkinson]

I have not found a way to write Colors-Auto-White Balance within Script-fu. Please advise how to do this.

[Ofnuts]

Why do you need to write it since it is already written? Or you need to reproduce it? As far as I can tell the core is (gimp-drawable-color-balance drawable transfer-mode preserve-lum cyan-red magenta-green yellow-blue) with some heuristics (possibly using (gimp-drawable-histogram drawable channel start-range end-range) on each RGB channel) to determine how to change the color balance.

[James Parkinson]

(12-02-2022, 06:16 PM)Ofnuts Wrote: Why do you need to write it since it is already written? Or you need to reproduce it? As far as I can tell the core is (gimp-drawable-color-balance drawable transfer-mode preserve-lum cyan-red magenta-green yellow-blue) with some heuristics (possibly using  (gimp-drawable-histogram drawable channel start-range end-range) on each RGB channel) to determine how to change the color balance.

Much thanks for sharing your knowledge.

I was needing to process batches of photos. The GIMP interactive is too slow.

The Colors-Auto-White Balance is not understood by myself. You have an understanding of what Auto-White Balance in detail is doing, which I don't possess.

If convinent please breakdown your script and explain its parts.

[rich2005]

It is difficult for Gimp new-comers to get into scripting. In all the years I have used Gimp, I think I only once got a script-fu batch to work

There is a GUI option BIMP see: https://alessandrofrancesconi.it/projects/bimp/  There is a Windows installer. Read the info on the site, examples are shown.

You can add a folder of images

   

Use other Gimp procedure and search for auto. It say it is deprecated but works anyway

   

Always best to export to another folder "just in case"

   

Set it going, BIMP does not break any speed records but better than one-at-a-time

However, if you need a script-fu procedure, I am sure Ofnuts will assist.

[James Parkinson]

I am familar with BIMP.

The Auto-White Balance at its details is a mystery, in otherwords propriatary information. I need to understand how it works to replicate it with script-fu.

I will make it a project to be completed someday.

Much thanks for your help.

[tmanni]

Gimp is a free software, so everything is freely available online, there is no "propriatary information".

The description of what happens is in the documentation : https://docs.gimp.org/en/gimp-layer-white-balance.html
The implementation of the algorithm is here and deeper here.