Create pdf2png.py

pdf2png.py

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+# /// script
+# requires-python = ">=3.10"
+# dependencies = ["pypdfium2>=4.30", "pillow>=10"]
+# ///
+r"""Render every page of every PDF under INPUT to PNG under OUTPUT, one folder per PDF:
+
+    INPUT/1850s/vol1.pdf  ->  OUTPUT/1850s/vol1/page-0001.png, page-0002.png, ...
+
+PDFs finished on an earlier run are skipped, so a run that stops partway
+(e.g. a job hitting its timeout) can simply be started again.
+
+    uv run pdf2png.py ./pdfs ./pages
+
+    hf jobs uv run --flavor cpu-upgrade --timeout 2h \
+        -v hf://datasets/USER/pdfs:/in -v hf://buckets/USER/pages:/out \
+        -- https://huggingface.co/datasets/USER/scripts/resolve/main/pdf2png.py /in /out
+"""
+
+import argparse
+import os
+import sys
+from concurrent.futures import ProcessPoolExecutor, as_completed
+from pathlib import Path
+
+import pypdfium2 as pdfium
+
+DONE = ".done"  # written into a PDF's output folder once all of its pages are saved
+
+
+def convert(pdf_path: Path, out_dir: Path, dpi: int, grayscale: bool) -> int:
+    pdf = pdfium.PdfDocument(pdf_path)
+    try:
+        pdf.init_forms()  # so filled-in form fields render as they do in a viewer
+        n = len(pdf)
+        width = max(4, len(str(n)))
+        out_dir.mkdir(parents=True, exist_ok=True)
+        for i in range(n):
+            page = pdf[i]
+            image = page.render(scale=dpi / 72, grayscale=grayscale).to_pil()
+            # still lossless; ~3x faster than the default level on scans, files ~10% larger
+            image.save(out_dir / f"page-{i + 1:0{width}d}.png", compress_level=1)
+            page.close()
+    finally:
+        pdf.close()
+    (out_dir / DONE).touch()
+    return n
+
+
+def main() -> None:
+    parser = argparse.ArgumentParser(description=__doc__, formatter_class=argparse.RawDescriptionHelpFormatter)
+    parser.add_argument("input", type=Path, help="folder of PDFs (searched recursively), or a single PDF")
+    parser.add_argument("output", type=Path, help="folder to write the PNGs to")
+    parser.add_argument("--dpi", type=int, default=300, help="render resolution (default: 300)")
+    parser.add_argument("--grayscale", action="store_true", help="8-bit grayscale PNGs: smaller files, faster")
+    parser.add_argument("--workers", type=int, default=int(os.environ.get("CPU_CORES") or os.cpu_count() or 1),
+                        help="parallel processes (default: one per CPU core)")
+    args = parser.parse_args()
+
+    if args.input.is_file():
+        root, pdfs = args.input.parent, [args.input]
+    else:
+        root = args.input
+        pdfs = sorted(p for p in root.rglob("*") if p.suffix.lower() == ".pdf" and p.is_file())
+    todo = {}
+    for pdf in pdfs:
+        out_dir = args.output / pdf.relative_to(root).with_suffix("")
+        if not (out_dir / DONE).exists():
+            todo[pdf] = out_dir
+    print(f"{len(pdfs)} PDFs found, {len(pdfs) - len(todo)} already done, {len(todo)} to convert", flush=True)
+    if not todo:
+        return
+
+    failed = []
+    with ProcessPoolExecutor(min(args.workers, len(todo))) as pool:
+        futures = {pool.submit(convert, pdf, out, args.dpi, args.grayscale): pdf for pdf, out in todo.items()}
+        for i, future in enumerate(as_completed(futures), 1):
+            name = futures[future].relative_to(root)
+            try:
+                print(f"[{i}/{len(todo)}] {name}: {future.result()} pages", flush=True)
+            except Exception as e:
+                failed.append(str(name))
+                print(f"[{i}/{len(todo)}] {name}: FAILED ({e})", flush=True)
+    if failed:
+        sys.exit(f"{len(failed)} PDF(s) failed: {', '.join(failed)}")
+
+
+if __name__ == "__main__":
+    main()