flat_pdf.sh

#!/usr/bin/env bash
# flat_pdf.sh - Bake PDF annotations into page content (flatten)
# Usage: flat_pdf.sh input.pdf
# Output: input-flat.pdf

set -e

if [[ $# -ne 1 ]]; then
    echo "Usage: $0 input.pdf"
    exit 1
fi

INPUT="$1"
BASENAME="${INPUT%.pdf}"
OUTPUT="${BASENAME}-flat.pdf"

if [[ ! -f "$INPUT" ]]; then
    echo "Error: file not found: $INPUT"
    exit 1
fi

python3 - "$INPUT" "$OUTPUT" << 'EOF'
import sys
import fitz  # PyMuPDF

src_path, dst_path = sys.argv[1], sys.argv[2]

src = fitz.open(src_path)
dst = fitz.open()

for page in src:
    w, h = page.rect.width, page.rect.height
    mat = fitz.Matrix(6, 6)  # 432 DPI
    pix = page.get_pixmap(matrix=mat, alpha=False, annots=True)
    new_page = dst.new_page(width=w, height=h)
    new_page.insert_image(new_page.rect, pixmap=pix)

dst.save(dst_path, deflate=True)
print(f"Saved: {dst_path}")
EOF