04-25-2020, 09:12 AM
Quote: How can a I make a palette colour transparent?
Not possible with Gimp, there are utilities such as gifsicle which can assign a colormap colour as transparency but it will screw up your image anyway.
A re-make as Ofnuts post will give a better result, however it might be possible:
I did need the gimp_gmic_qt plugin http://www.gmic.eu and it went something like this:
Use the quickmask to select all the individual icons
Copy then paste as a new image
Use gmic to (1) extract the icons to individual layers (2) rotate the layers 180 deg.
Put the new image back in original and rotate 180 deg
The inevitable demo video, four and a half minutes: https://youtu.be/TfGIncp0pJg
Hope you do not have hundreds of these to process
