Files
pdf_signature_extraction/yolo_full_scan.py
T
gbanyan 939a348da4 Add Paper A (IEEE TAI) complete draft with Firm A-calibrated dual-method classification
Paper draft includes all sections (Abstract through Conclusion), 36 references,
and supporting scripts. Key methodology: Cosine similarity + dHash dual-method
verification with thresholds calibrated against known-replication firm (Firm A).

Includes:
- 8 section markdown files (paper_a_*.md)
- Ablation study script (ResNet-50 vs VGG-16 vs EfficientNet-B0)
- Recalibrated classification script (84,386 PDFs, 5-tier system)
- Figure generation and Word export scripts
- Citation renumbering script ([1]-[36])
- Signature analysis pipeline (12 steps)
- YOLO extraction scripts

Three rounds of AI review completed (GPT-5.4, Claude Opus 4.6, Gemini 3 Pro).

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
2026-04-06 23:05:33 +08:00

386 lines
13 KiB
Python

#!/usr/bin/env python3
"""
YOLO Full PDF Signature Scanner
Scans all PDFs to detect handwritten signatures using a trained YOLOv11n model.
Supports multi-process GPU acceleration and checkpoint resumption.
Features:
- Skip first page of each PDF
- Stop scanning once signature is found
- Extract and save signature crops with red stamp removal
- Progress checkpoint for resumption
- Detailed statistics report
"""
import argparse
import csv
import json
import os
import sys
import time
from concurrent.futures import ProcessPoolExecutor, as_completed
from datetime import datetime
from pathlib import Path
from typing import Optional
import cv2
import fitz # PyMuPDF
import numpy as np
# Will be imported in worker processes
# from ultralytics import YOLO
# Configuration
DPI = 150 # Lower DPI for faster processing (150 vs 300)
CONFIDENCE_THRESHOLD = 0.5
PROGRESS_SAVE_INTERVAL = 100 # Save progress every N files
def remove_red_stamp(image: np.ndarray) -> np.ndarray:
"""Remove red stamp pixels from an image by replacing them with white."""
hsv = cv2.cvtColor(image, cv2.COLOR_RGB2HSV)
# Red color ranges in HSV
lower_red1 = np.array([0, 50, 50])
upper_red1 = np.array([10, 255, 255])
lower_red2 = np.array([160, 50, 50])
upper_red2 = np.array([180, 255, 255])
mask1 = cv2.inRange(hsv, lower_red1, upper_red1)
mask2 = cv2.inRange(hsv, lower_red2, upper_red2)
red_mask = cv2.bitwise_or(mask1, mask2)
kernel = np.ones((3, 3), np.uint8)
red_mask = cv2.dilate(red_mask, kernel, iterations=1)
result = image.copy()
result[red_mask > 0] = [255, 255, 255]
return result
def render_pdf_page(doc, page_num: int, dpi: int = DPI) -> Optional[np.ndarray]:
"""Render a PDF page to an image array."""
try:
page = doc[page_num]
mat = fitz.Matrix(dpi / 72, dpi / 72)
pix = page.get_pixmap(matrix=mat, alpha=False)
image = np.frombuffer(pix.samples, dtype=np.uint8)
image = image.reshape(pix.height, pix.width, pix.n)
return image
except Exception:
return None
def scan_single_pdf(args: tuple) -> dict:
"""
Scan a single PDF for signatures.
Args:
args: Tuple of (pdf_path, model_path, output_dir, conf_threshold)
Returns:
Result dictionary with signature info
"""
pdf_path, model_path, output_dir, conf_threshold = args
# Import here to avoid issues with multiprocessing
from ultralytics import YOLO
result = {
'filename': os.path.basename(pdf_path),
'source_dir': os.path.basename(os.path.dirname(pdf_path)),
'has_signature': False,
'page': None,
'num_signatures': 0,
'confidence_avg': 0.0,
'error': None
}
try:
# Load model (each worker loads its own)
model = YOLO(model_path)
doc = fitz.open(pdf_path)
num_pages = len(doc)
# Skip first page, scan remaining pages
for page_num in range(1, num_pages): # Start from page 2 (index 1)
image = render_pdf_page(doc, page_num)
if image is None:
continue
# Run YOLO detection
results = model(image, conf=conf_threshold, verbose=False)
signatures = []
for r in results:
for box in r.boxes:
x1, y1, x2, y2 = map(int, box.xyxy[0].cpu().numpy())
conf = float(box.conf[0].cpu().numpy())
signatures.append({
'box': (x1, y1, x2 - x1, y2 - y1),
'xyxy': (x1, y1, x2, y2),
'confidence': conf
})
if signatures:
# Found signatures! Record and stop scanning
result['has_signature'] = True
result['page'] = page_num + 1 # 1-indexed
result['num_signatures'] = len(signatures)
result['confidence_avg'] = sum(s['confidence'] for s in signatures) / len(signatures)
# Extract and save signature crops
base_name = Path(pdf_path).stem
for i, sig in enumerate(signatures):
x, y, w, h = sig['box']
x = max(0, x)
y = max(0, y)
x2 = min(image.shape[1], x + w)
y2 = min(image.shape[0], y + h)
crop = image[y:y2, x:x2]
crop_no_stamp = remove_red_stamp(crop)
# Save to output directory
crop_filename = f"{base_name}_page{page_num + 1}_sig{i + 1}.png"
crop_path = os.path.join(output_dir, "images", crop_filename)
cv2.imwrite(crop_path, cv2.cvtColor(crop_no_stamp, cv2.COLOR_RGB2BGR))
doc.close()
return result
doc.close()
except Exception as e:
result['error'] = str(e)
return result
def collect_pdf_files(input_dirs: list[str]) -> list[str]:
"""Collect all PDF files from input directories."""
pdf_files = []
for input_dir in input_dirs:
input_path = Path(input_dir)
if not input_path.exists():
print(f"Warning: Directory not found: {input_dir}")
continue
# Check for batch subdirectories
batch_dirs = list(input_path.glob("batch_*"))
if batch_dirs:
# Has batch subdirectories
for batch_dir in sorted(batch_dirs):
for pdf_file in batch_dir.glob("*.pdf"):
pdf_files.append(str(pdf_file))
else:
# Flat directory
for pdf_file in input_path.glob("*.pdf"):
pdf_files.append(str(pdf_file))
return sorted(pdf_files)
def load_progress(progress_file: str) -> set:
"""Load completed files from progress checkpoint."""
if os.path.exists(progress_file):
try:
with open(progress_file, 'r') as f:
data = json.load(f)
return set(data.get('completed_files', []))
except Exception:
pass
return set()
def save_progress(progress_file: str, completed: set, total: int, start_time: float):
"""Save progress checkpoint."""
elapsed = time.time() - start_time
data = {
'last_updated': datetime.now().isoformat(),
'total_pdfs': total,
'processed': len(completed),
'remaining': total - len(completed),
'elapsed_seconds': elapsed,
'completed_files': list(completed)
}
with open(progress_file, 'w') as f:
json.dump(data, f)
def main():
parser = argparse.ArgumentParser(description='YOLO Full PDF Signature Scanner')
parser.add_argument('--input', nargs='+', required=True, help='Input directories containing PDFs')
parser.add_argument('--output', required=True, help='Output directory for results')
parser.add_argument('--model', default='best.pt', help='Path to YOLO model')
parser.add_argument('--workers', type=int, default=4, help='Number of parallel workers')
parser.add_argument('--conf', type=float, default=0.5, help='Confidence threshold')
parser.add_argument('--resume', action='store_true', help='Resume from checkpoint')
args = parser.parse_args()
# Setup output directories
output_dir = Path(args.output)
output_dir.mkdir(parents=True, exist_ok=True)
(output_dir / "images").mkdir(exist_ok=True)
progress_file = str(output_dir / "progress.json")
csv_file = str(output_dir / "yolo_signatures.csv")
report_file = str(output_dir / "scan_report.json")
print("=" * 70)
print("YOLO Full PDF Signature Scanner")
print("=" * 70)
print(f"Input directories: {args.input}")
print(f"Output directory: {args.output}")
print(f"Model: {args.model}")
print(f"Workers: {args.workers}")
print(f"Confidence threshold: {args.conf}")
print(f"Resume mode: {args.resume}")
print("=" * 70)
# Collect all PDF files
print("\nCollecting PDF files...")
all_pdfs = collect_pdf_files(args.input)
total_pdfs = len(all_pdfs)
print(f"Found {total_pdfs} PDF files")
# Load progress if resuming
completed_files = set()
if args.resume:
completed_files = load_progress(progress_file)
print(f"Resuming from checkpoint: {len(completed_files)} files already processed")
# Filter out already processed files
pdfs_to_process = [p for p in all_pdfs if os.path.basename(p) not in completed_files]
print(f"PDFs to process: {len(pdfs_to_process)}")
if not pdfs_to_process:
print("All files already processed!")
return
# Prepare arguments for workers
work_args = [
(pdf_path, args.model, str(output_dir), args.conf)
for pdf_path in pdfs_to_process
]
# Statistics
results_with_sig = []
results_without_sig = []
errors = []
source_stats = {}
start_time = time.time()
processed_count = len(completed_files)
# Process with multiprocessing
print(f"\nStarting scan with {args.workers} workers...")
print("-" * 70)
with ProcessPoolExecutor(max_workers=args.workers) as executor:
futures = {executor.submit(scan_single_pdf, arg): arg[0] for arg in work_args}
for future in as_completed(futures):
pdf_path = futures[future]
filename = os.path.basename(pdf_path)
try:
result = future.result()
# Update statistics
source_dir = result['source_dir']
if source_dir not in source_stats:
source_stats[source_dir] = {'scanned': 0, 'with_sig': 0}
source_stats[source_dir]['scanned'] += 1
if result['error']:
errors.append(result)
elif result['has_signature']:
results_with_sig.append(result)
source_stats[source_dir]['with_sig'] += 1
else:
results_without_sig.append(result)
# Track completion
completed_files.add(filename)
processed_count += 1
# Progress output
elapsed = time.time() - start_time
rate = (processed_count - len(load_progress(progress_file) if args.resume else set())) / elapsed if elapsed > 0 else 0
eta = (total_pdfs - processed_count) / rate / 3600 if rate > 0 else 0
status = "SIG" if result['has_signature'] else "---"
print(f"[{processed_count}/{total_pdfs}] {status} {filename[:50]:50s} "
f"({rate:.1f}/s, ETA: {eta:.1f}h)")
# Save progress periodically
if processed_count % PROGRESS_SAVE_INTERVAL == 0:
save_progress(progress_file, completed_files, total_pdfs, start_time)
except Exception as e:
print(f"Error processing {filename}: {e}")
errors.append({'filename': filename, 'error': str(e)})
# Final progress save
save_progress(progress_file, completed_files, total_pdfs, start_time)
# Write CSV index
print("\nWriting CSV index...")
with open(csv_file, 'w', newline='') as f:
writer = csv.DictWriter(f, fieldnames=['filename', 'page', 'num_signatures', 'confidence_avg'])
writer.writeheader()
for result in results_with_sig:
writer.writerow({
'filename': result['filename'],
'page': result['page'],
'num_signatures': result['num_signatures'],
'confidence_avg': round(result['confidence_avg'], 4)
})
# Generate report
elapsed_total = time.time() - start_time
report = {
'scan_date': datetime.now().isoformat(),
'total_pdfs': total_pdfs,
'with_signature': len(results_with_sig),
'without_signature': len(results_without_sig),
'errors': len(errors),
'signature_rate': f"{len(results_with_sig) / total_pdfs * 100:.2f}%" if total_pdfs > 0 else "0%",
'total_signatures_extracted': sum(r['num_signatures'] for r in results_with_sig),
'processing_time_hours': round(elapsed_total / 3600, 2),
'processing_rate_per_second': round(len(pdfs_to_process) / elapsed_total, 2) if elapsed_total > 0 else 0,
'source_breakdown': source_stats,
'model': args.model,
'confidence_threshold': args.conf,
'workers': args.workers
}
with open(report_file, 'w') as f:
json.dump(report, f, indent=2)
# Print summary
print("\n" + "=" * 70)
print("SCAN COMPLETE")
print("=" * 70)
print(f"Total PDFs scanned: {total_pdfs}")
print(f"With signature: {len(results_with_sig)} ({len(results_with_sig)/total_pdfs*100:.1f}%)")
print(f"Without signature: {len(results_without_sig)} ({len(results_without_sig)/total_pdfs*100:.1f}%)")
print(f"Errors: {len(errors)}")
print(f"Total signatures: {sum(r['num_signatures'] for r in results_with_sig)}")
print(f"Processing time: {elapsed_total/3600:.2f} hours")
print(f"Processing rate: {len(pdfs_to_process)/elapsed_total:.1f} PDFs/second")
print("-" * 70)
print(f"Results saved to: {output_dir}")
print("=" * 70)
if __name__ == "__main__":
main()