A script to watch a directory and automatically combine pairs of PDF files with interleaved pages, ideal for reconstructing double-sided documents scanned on a simplex (single-sided) ADF scanner. Utilizes PDFtk

• Linux (e.g., Ubuntu)
• PDFtk
• inotify-tools

Install prerequisites on Ubuntu:

sudo apt-get -y install pdftk inotify-tools

The scanmultipage script is designed to monitor a specified directory for pairs of PDF files, then automatically combine them into a single, correctly ordered, double-sided document. This is particularly useful for users with a simplex (single-sided) scanner that can only scan one side at a time. By scanning the odd and even pages separately, and then using this script, users can create properly ordered double-sided PDFs.

1. Watch Folder Setup:

   • The script monitors a designated "watch folder" for incoming PDF files.
   • Each time two new PDF files are detected, the script assumes that:
     • The first file contains the odd-numbered pages.
     • The second file contains the even-numbered pages in reverse order.

2. Combining Files:

   • The script processes each pair of PDF files by:
     1. Reversing the pages in the even-numbered PDF file so they are in the correct order.
     2. Interleaving pages from the odd and reversed even PDFs to create a combined, properly ordered, double-sided document.
   • The final PDF is saved in a specified output directory with a timestamped filename for easy identification.

• PDF Processing Tools: The script relies on pdftk for reversing and interleaving pages.
• inotify-tools: The script uses inotifywait to monitor the watch folder for new files.

To run scanmultipage.sh, provide the paths for the watch folder and output folder as command-line arguments. This setup allows flexibility, enabling multiple instances of the script to run with different folder configurations.

Example:

./scanmultipage.sh /path/to/watch_folder /path/to/output_folder

1. Clone the repository and copy files:

git clone https://github.com/efnats/scanmultipage
cd scanmultipage
sudo cp ./scanmultipage.sh /usr/local/bin
sudo chmod +x /usr/local/bin/scanmutipage.sh
sudo cp ./scanmultipage.service /etc/systemd/system/

2. Adjust the service file by adjusting file paths according to your needs

3. Setup the service:

sudo systemctl daemon-reload
sudo systemctl enable scanmultipage.service
sudo systemctl start scanmultipage.service