03-20-2025, 11:38 PM
(03-20-2025, 02:50 AM)exxo Wrote: I also have a question about channels so figured I'd add here.
Context:
I'm learning how to conduct image integrity checks on scientific articles. One way to check for duplications is to copy the 2 suspected duplicate images into a new file, one in the red channel and the other in green. Reducing opacity and overlaying them then makes it clear what matches and what doesn't.
Issue:
I have my two sections in separate layers on the same canvas but cannot figure out how to lock one into the green channel and the other into red. Each time it just changes the entire canvas and all layers to the selected channel. I've tried decomposing and selecting but cannot seem to get that to work either.
Any suggestions?
You can do like everyone does, set the top image to "difference" mode. If the images are identical you get black, otherwise you get something more visible.
If you still want to use color channels:
- You can replace each image by one of its channels using Colors > Component > Extract component
- Better solution:
- Put each image in a group
- A layer in the group above each image
- Bucket fill that layer with the channel you want to extract (red, green, blue...)
- Set the color layer to Multiply
- Put each image in a group