Conver PDF to Dark mode

README.md

pip3 install pymupdf

chmod +x pdf2dark.py

./pdf2dark.py inputfile.pdf -o output.pdf

pdf2dark.py

#!/usr/bin/env python3
import fitz  # PyMuPDF
import argparse
from pathlib import Path

def convert_to_dark_mode(input_path, output_path):
    """
    Convert a PDF to dark mode by rendering pages as images and reconstructing
    """
    try:
        # Open the input PDF
        pdf_document = fitz.open(input_path)
        
        # Create a new PDF for output
        out_doc = fitz.open()
        
        for page_num in range(len(pdf_document)):
            # Get the original page
            page = pdf_document[page_num]
            
            # Create a pixmap of the page with white text on black background
            # Using a higher zoom factor for better quality
            zoom = 3  # Increase this for higher quality, decrease for better performance
            mat = fitz.Matrix(zoom, zoom)
            pix = page.get_pixmap(matrix=mat)
            
            # Invert the colors
            pix.invert_irect(None)  # None means the entire image
            
            # Create a new page in the output PDF
            new_page = out_doc.new_page(width=page.rect.width, height=page.rect.height)
            
            # Insert the inverted image into the new page, scaling it back to original size
            new_page.insert_image(new_page.rect, pixmap=pix)
        
        # Save the modified PDF
        out_doc.save(
            output_path,
            garbage=4,
            deflate=True,
            clean=True
        )
        
        # Close documents
        out_doc.close()
        pdf_document.close()
        
        print(f"Successfully converted PDF to dark mode: {output_path}")
        return True
        
    except Exception as e:
        print(f"Error converting PDF: {str(e)}")
        return False

def main():
    parser = argparse.ArgumentParser(description='Convert a PDF to dark mode')
    parser.add_argument('input_pdf', help='Path to the input PDF file')
    parser.add_argument('-o', '--output', help='Path for the output PDF file (optional)')
    parser.add_argument(
        '-q', '--quality',
        type=int,
        choices=[1, 2, 3, 4],
        default=2,
        help='Quality level (1-4, default=2, higher is better but slower)'
    )
    
    args = parser.parse_args()
    input_path = Path(args.input_pdf)
    
    if args.output:
        output_path = Path(args.output)
    else:
        output_path = input_path.parent / f"{input_path.stem}_dark{input_path.suffix}"
    
    convert_to_dark_mode(str(input_path), str(output_path))

if __name__ == "__main__":
    main()