- If images are not in grayscale, convert to grayscale
- Open all three images
- Select all on one image, then copy
- File –> New
- Choose black background by clicking arrow (this will ensure RGB)
- Click on red channel, and paste in red image (as grayscale)
- Click on green channel and past in green image (as grayscale)
- Click on blue channel and past in blue image (as grayscale)
- Images must be aligned. This is best done while zoomed in.
- When alignment seems complete, toggle channels on and off to confirm their alignment and make final adjustments.
