pdf-wtf

PDF - what the file format ...

PDF files parsing and data extraction

Work in progress ...

Built on top of

pikepdf

• PDF manipulation and content editing
• https://pikepdf.readthedocs.io/en/latest/installation.html

PyMuPDF

• PDF processing, text/image extraction, rendering
• https://pymupdf.readthedocs.io/en/latest/installation.html

ocrmypdf

• OCR wrapper (uses Tesseract + Ghostscript)
• https://ocrmypdf.readthedocs.io/en/latest/installation.html

External non-Python dependencies

Tesseract OCR

• required by OCRmyPDF and PyMuPDF
• https://github.com/UB-Mannheim/tesseract

Ghostscript

• required by OCRmyPDF
• https://www.ghostscript.com/releases/gsdnld.html

unpaper

• required by OCRmyPDF with some params: --clean etc.
• https://github.com/unpaper/unpaper

pngquant

• required by OCRmyPDF with optimize > 0
• https://pngquant.org/

Local dev installation

Prerequisites: Python 3.12+, Git

Open terminal/command line

• create the repo dir
• go to the dir

1. Clone the repo:

   git clone https://github.com/filak/pdf-wtf

2. Install uv package manager and create the virtual environment:

   pip install uv
   
   uv venv
   

3. Activate the environment:

   .venv\Scripts\activate
   

4. Install dependecies:

   uv sync
   

5. Test - run:

   pytest
   

Updating the deps

uv add <package>==<version>

Using unpaper on Windows

OCRmyPDF requires unpaper installed to be able to use --clean and --clean_final params

Install and start Docker Desktop

Build the Docker image - run:

 docker build -t unpaper-alpine -f .Dockerfile-unpaper .

Test run:

 docker run --rm unpaper-alpine --version

Create ENV vars:

 setx PDFWTF_HOME_DIR d:\Decko\pdf-wtf
 setx PDFWTF_TEMP_DIR %PDFWTF_HOME_DIR%\instance\temp

Add %PDFWTF_HOME_DIR% to PATH so OCRmyPDF can find the unpaper.cmd

Check:

 echo  %PDFWTF_HOME_DIR%  %PDFWTF_TEMP_DIR%

 unpaper.cmd --version

Patch for ocrmypdf to use unpaper on Windows using Docker

\.venv\Lib\site-packages\ocrmypdf\subprocess\_windows.py#180  

def fix_windows_args():
...
# Patch for Windows - ".\\unpaper"
if sys.platform.startswith("win"):
    if args[0].startswith(".\\unpaper."):
        args[0] = args[0].lstrip(".\\")

If you reinstall the package - you MUST insert the patch again !