Occasionally I have to sign some document (old style, with a pen) and send it electronically. Sometimes those are multi-page documents. Since it is uncommon to send it back as multiple image files after scanning, and multi-page image formats are uncommon as well, I’d like to send them as PDF file. Before I discovered this method, I used to insert the scanned images into OpenOffice Writer, and then create the PDF with it. This works, but it is a bit cumbersome to tell OpenOffice Writer to maximise the images (eliminating page borders, etc.), especially when there are a lot of pages. It just doesn’t feel like a real solution.

So, here we go:

Prerequisites:

• GIMP (I’m currently at version 2.6.8, but this will probably work with older versions as well)
• GraphicsMagick (tested with 1.3.8) or ImageMagick (tested with 6.5.8.8)

Procedure:

1. Get the scanned pages opened as layers of one image in GIMP. If they are available as files already, you can use File / Open as Layers….
2. Make sure that the layers are ordered in the following way: Page 1 must be the bottom layer, the last page must be the top layer. You can reorder them via the “Layers” dialogue (activate it via the Windows / Dockable Dialogues menu if you don’t see it)
3. Save As… and choose “MNG animation” or just add “.mng” to the filename. (In case you are wondering, MNG is the animated counterpart to PNG).
   A dialogue window saying “MNG plug-in can only handle layers as animation frames” will come up – choose “Save as Animation” here and press the Export button. In the next dialogue you don’t need to make any changes to the defaults, just press the Save button.
4. Now, open a console window and simply enter
   convert document.mng document.pdf