What you have to do:

1. Remove the staples of your leaflet.
2. Create a new folder for your images to scan.
3. Scan the batch of leaflet pages as PNG image files.
4. First scan the outer pages starting with the cover.
5. Then scan the inner pages starting with the cover.
6. Run the script convert.sh (see above) in the folder containing the *.PNG images.
7. Staple the leaflet again.