Finds differences between two PDF documents:
Compares the text layers of two PDF documents and outputs the bounding boxes of changed text in JSON. Rasterizes the changed pages in the PDFs to a PNG and draws red outlines around changed text.
The script is written in Python 3, and it relies on thepdftotext program.
libxml2 >= 2.7.0, libxslt >= 1.1.23, popplerRequirements installation for Ubuntu: sudo apt-get install python3-lxml poppler-utilsRequirements installation for OS X: brew install libxml2 libxslt popplerFrom PyPI:
From source:
sudo python3 setup.py installTurn two PDFs into one large PNG image showing the differences:
pdf-diff before.pdf after.pdf > comparison_output.pngTo deploy:
python3 -m pip install --user --upgrade setuptools wheel twinepython3 setup.py sdist bdist_wheelpython3 -m twine upload dist/*compute_changes│├── serialize_pdf (called twice)│ ├── pdf_to_bboxes│ ├── mark_eol_hyphens│ │ └── mark_eol_hyphen│ └── Processes bounding boxes and text│├── perform_diff│ └── Calls external `fast_diff_match_patch`│└── process_hunks ├── Iterates through diff hunks └── mark_difference (called multiple times)render_changes│├── simplify_changes├── make_pages_images│ └── pdftopng (converts PDF pages to images)├── realign_pages│ ├── Splits pages into sub-pages│ └── Adjusts box coordinates├── draw_red_boxes│ └── Annotates images with rectangles or lines└── zealous_crop └── Crops the image to reduce unnecessary marginsstack_pages│└── Combines processed images into a final output