How do I save scanned images in PDF format?

To save images in PDF format, you will need to change the specific profile settings in ScanSnap Home.

To change the profile settings:

1.  Open the [Edit profiles] window.
   
   
   
2. Select the profile you want to change.
3. Select [PDF (*.pdf)] for [File format] in [Scan settings].

For details:
ScanSnap Help
(Select the model name of the ScanSnap at the top of the page)