pdfmerge

TL;DR
A docker-container that watches for incoming files (incrond) and merges them together (using qpdf) if needed.

The reason I created this project, is a scanner (HP OfficeJet) whose duplex unit sucks. It can’t handle folded sheets well (paperjam in 8 out of 10 cases). So I need to scan the odd and even pages separately and merge them together afterwards.
The docker-container is running on my NAS (QNAP TS-251+) and watches for new files in a mounted volume, in which the scanner saves it files. The files are prefixed based on scan-profiles and merged based on these prefixes.
For convenience I reverse the order of the even pages and rotate them by 180 degree during the merge process. Doing that I can simply take the scanned pages from the output tray and put them back to the input feeder without the need to rotate and reorder them.

Example usage:

> docker pull rverst/pdfmerge
> docker run -v /scan_folder:/input \
             -v /scan_folder:/output \
             rverst/pdfmerge:latest

Note that the script runs as UID 1000 and GID 1000 by default. These may be altered with the PUID and PGID environment variables.

Environment variables:

• PUID - UID to use
• GUID - GID to use
• WAIT_TIMEOUT - timeout in sec. the script waits for a file to close. Should not be to short since some scanners create the file at the beginning of the scan.
• ROTATE_ODD - rotate the odd pages
• ROTATE_EVEN - rotate the even pages
• REVERSE_EVEN - reverse the order of the even pages

Alternatives:

• docker-mergepdf - Inspiration for this little project.