Files
AI-Prototype/scripts/ocr_wardiaries.py
2026-05-13 10:03:38 -04:00

304 lines
10 KiB
Python

"""
ocr_wardiaries.py
-----------------
Converts war diary PDFs to plain text using the olmOCR model hosted on DeepInfra.
Bypasses the olmOCR pipeline GPU check by calling the API directly.
Output format: plain text only — no markdown, no HTML, no tables.
Each diary entry is transcribed as prose with a blank line between entries.
Requirements:
pip install requests pillow
Poppler must be on PATH (pdftoppm command must work).
Usage:
python ocr_wardiaries.py --input_dir "C:/path/to/pdfs" --output_dir "C:/path/to/output" --api_key "YOUR_KEY"
python ocr_wardiaries.py --single "C:/path/to/diary.pdf" --output_dir "C:/path/to/output" --api_key "YOUR_KEY"
"""
import argparse
import base64
import os
import subprocess
import sys
import tempfile
import time
from pathlib import Path
import requests
from PIL import Image
# ---------------------------------------------------------------------------
# Configuration
# ---------------------------------------------------------------------------
DEEPINFRA_API_URL = "https://api.deepinfra.com/v1/openai/chat/completions"
MODEL = "allenai/olmOCR-2-7B-1025"
DPI = 150 # Higher = better quality but slower/more expensive. 150 is good for typewritten text.
MAX_RETRIES = 3 # Retries per page on API error
RETRY_DELAY = 5 # Seconds between retries
# ---------------------------------------------------------------------------
# OCR prompt
# ---------------------------------------------------------------------------
# Plain text only — no markdown, no HTML.
# War diary pages are tabular (Place / Date / Hour / Summary).
# We transcribe each row as prose to avoid HTML table output
# which causes downstream parsing problems.
SYSTEM_PROMPT = """\
You are transcribing a scanned WWII Canadian Army war diary page.
Output plain text only. No markdown. No HTML. No tables. No formatting symbols.
Rules:
- Transcribe ALL text visible on the page. Every word, every field, every stamp, every notation.
- Do not decide what is important. Do not skip anything. Transcribe everything.
- Do not correct spelling, grammar, or abbreviations. Transcribe exactly as written.
- If the page has a table with columns (Place / Date / Hour / Summary), transcribe each row \
as continuous prose in this format:
[DATE] [PLACE]: [SUMMARY TEXT]
Example: 4 Sep 44 France, NEUVILLE Les DIEPPE MR 2468 Sheet: The main topic for the morning...
- Separate multiple diary entries with a single blank line.
- Keep grid references exactly as written (e.g. MR 2468, GR 442891, MR 0675 Sheet).
- Keep military abbreviations exactly as written (e.g. Bn, Bde, HQ, OR, C.O., R de Mais, RHC).
- Weather notes go on their own line starting with: Weather:
- Transcribe page headers, form titles, stamps, handwritten notes, signatures, \
and margin notations — all of it.
- If a page is genuinely blank with no text at all, output only: [NO DIARY CONTENT]
- Do not add commentary, explanations, confidence notes, or summaries.
- Do not output page numbers or headings.
- Do not use asterisks, hashes, pipes, underscores, or any other formatting characters.\
"""
USER_PROMPT = (
"Transcribe every word on this war diary page exactly as written. "
"Plain text only — include all text visible on the page, nothing omitted."
)
# ---------------------------------------------------------------------------
# Helpers
# ---------------------------------------------------------------------------
def pdf_to_images(pdf_path: Path, output_dir: Path, dpi: int = DPI,
first_page: int = None, last_page: int = None) -> list[Path]:
"""Render each page of a PDF to a PNG image using pdftoppm (poppler)."""
prefix = output_dir / pdf_path.stem
cmd = [
"pdftoppm",
"-r", str(dpi),
"-png",
]
if first_page is not None:
cmd += ["-f", str(first_page)]
if last_page is not None:
cmd += ["-l", str(last_page)]
cmd += [str(pdf_path), str(prefix)]
result = subprocess.run(cmd, capture_output=True, text=True)
if result.returncode != 0:
raise RuntimeError(f"pdftoppm failed for {pdf_path.name}:\n{result.stderr}")
images = sorted(output_dir.glob(f"{pdf_path.stem}-*.png"))
return images
def image_to_base64(image_path: Path) -> str:
"""Convert an image file to a base64 string."""
with open(image_path, "rb") as f:
return base64.b64encode(f.read()).decode("utf-8")
def ocr_page(image_path: Path, api_key: str, page_num: int) -> str:
"""Send one page image to DeepInfra olmOCR and return the extracted plain text."""
b64 = image_to_base64(image_path)
headers = {
"Content-Type": "application/json",
"Authorization": f"Bearer {api_key}",
}
payload = {
"model": MODEL,
"messages": [
{
"role": "system",
"content": SYSTEM_PROMPT,
},
{
"role": "user",
"content": [
{
"type": "image_url",
"image_url": {
"url": f"data:image/png;base64,{b64}"
},
},
{
"type": "text",
"text": USER_PROMPT,
},
],
}
],
"max_tokens": 4096,
"temperature": 0.0,
}
for attempt in range(1, MAX_RETRIES + 1):
try:
response = requests.post(
DEEPINFRA_API_URL,
headers=headers,
json=payload,
timeout=120,
)
response.raise_for_status()
data = response.json()
return data["choices"][0]["message"]["content"]
except requests.exceptions.HTTPError as e:
print(f" HTTP error on page {page_num}, attempt {attempt}/{MAX_RETRIES}: {e}")
if attempt < MAX_RETRIES:
time.sleep(RETRY_DELAY)
else:
return f"[OCR FAILED - page {page_num} - HTTP error: {e}]"
except Exception as e:
print(f" Error on page {page_num}, attempt {attempt}/{MAX_RETRIES}: {e}")
if attempt < MAX_RETRIES:
time.sleep(RETRY_DELAY)
else:
return f"[OCR FAILED - page {page_num} - Error: {e}]"
def ocr_pdf(pdf_path: Path, output_dir: Path, api_key: str, max_pages: int = None) -> Path:
"""OCR a single PDF and write output to a plain text file."""
print(f"\n{'='*60}")
print(f"Processing: {pdf_path.name}")
print(f"{'='*60}")
output_md = output_dir / f"{pdf_path.stem}_olmocr.md"
# Skip if already done
if output_md.exists():
print(f" Already processed — skipping.")
print(f" Delete {output_md.name} to reprocess.")
return output_md
with tempfile.TemporaryDirectory() as tmp_dir:
tmp_path = Path(tmp_dir)
# Render PDF pages to images
print(f" Rendering PDF pages to images at {DPI} DPI...")
try:
images = pdf_to_images(pdf_path, tmp_path, last_page=max_pages)
except RuntimeError as e:
print(f" ERROR: {e}")
return output_md
total_pages = len(images)
print(f" Found {total_pages} pages to process.")
# File header — plain text, no markdown
all_text = [
f"# {pdf_path.stem}",
f"OCR by olmOCR ({MODEL}) via DeepInfra",
f"Source: {pdf_path.name}{len(images)} page(s) processed",
"",
]
for i, image_path in enumerate(images, start=1):
print(f" Page {i}/{total_pages}...", end=" ", flush=True)
page_text = ocr_page(image_path, api_key, i)
# Each page is separated by a ## Page N marker so the viewer
# can split pages correctly. The content itself is plain text.
all_text.append(f"## Page {i}")
all_text.append("")
all_text.append(page_text.strip())
all_text.append("")
print("done")
# Small delay to avoid hammering the API
if i < total_pages:
time.sleep(0.5)
# Write output
output_dir.mkdir(parents=True, exist_ok=True)
with open(output_md, "w", encoding="utf-8") as f:
f.write("\n".join(all_text))
print(f" Saved: {output_md}")
return output_md
# ---------------------------------------------------------------------------
# Main
# ---------------------------------------------------------------------------
def main():
parser = argparse.ArgumentParser(
description="OCR war diary PDFs to plain text using olmOCR via DeepInfra."
)
parser.add_argument(
"--input_dir",
default=None,
help="Folder containing PDF files to process.",
)
parser.add_argument(
"--output_dir",
required=True,
help="Folder to write output files.",
)
parser.add_argument(
"--api_key",
required=True,
help="Your DeepInfra API key.",
)
parser.add_argument(
"--single",
default=None,
help="Process a single PDF file instead of a whole folder.",
)
parser.add_argument(
"--max_pages",
type=int,
default=None,
help="Only process the first N pages of each PDF (useful for testing).",
)
args = parser.parse_args()
output_dir = Path(args.output_dir)
output_dir.mkdir(parents=True, exist_ok=True)
if args.single:
pdfs = [Path(args.single)]
elif args.input_dir:
pdfs = sorted(Path(args.input_dir).glob("*.pdf"))
else:
print("Error: provide --input_dir or --single")
sys.exit(1)
if not pdfs:
print(f"No PDF files found.")
sys.exit(1)
print(f"Found {len(pdfs)} PDF(s) to process.")
print(f"Output directory: {output_dir}")
print(f"Model: {MODEL}")
print(f"DPI: {DPI}")
results = []
for pdf_path in pdfs:
output_md = ocr_pdf(pdf_path, output_dir, args.api_key, max_pages=args.max_pages)
results.append(output_md)
print(f"\n{'='*60}")
print(f"Complete. {len(results)} file(s) processed.")
print("Output files:")
for r in results:
print(f" {r}")
if __name__ == "__main__":
main()