gbanyan 980295d5bd Update §IV v3.3: soften §IV-D/E framing + rename §IV-I + add §IV-M
- §IV-D opening: note that the accountant-level dip rejection is
  fully explained by between-firm composition + integer ties per
  §III-I.4 (Scripts 39b-e), no longer "the empirical justification
  for fitting a mixture model"
- §IV-E Tables VII/VIII: K=2/K=3 component labels changed from
  "hand-leaning / mixed / replicated" to position-on-plane labels
  per §III-J recasting
- §IV-I retitled "Inter-CPA Pair-Level Coincidence Rate"; v3.x's
  "FAR" terminology retroactively reframed; references §IV-M for
  the v4 Big-4 spike (Script 40b)
- New §IV-M (7 tables XIX-XXV): v4-new anchor-based ICCR
  calibration results consolidated — composition decomposition
  (Scripts 39b-e), pair-level ICCR sweep (Script 40b), pool-
  normalised per-signature ICCR (Script 43), document-level
  ICCR by alarm definition (Script 45), firm-heterogeneity
  logistic regression + cross-firm hit matrix (Script 44),
  alert-rate sensitivity (Script 46)
- Header bumped to v3.3 (post codex rounds 21-34)

Companion to §III v7 commit 723a3f6 and Phase 4 prose v3 commit
b33e20d.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-05-13 18:18:59 +08:00

PDF Signature Extraction System

Automated extraction of handwritten Chinese signatures from PDF documents using hybrid VLM + Computer Vision approach.

Quick Start

Step 1: Extract Pages from CSV

cd /Volumes/NV2/pdf_recognize
source venv/bin/activate
python extract_pages_from_csv.py

Step 2: Extract Signatures

python extract_signatures_hybrid.py

Documentation

Current Performance

Test Dataset: 5 PDF pages

  • Signatures expected: 10
  • Signatures found: 7
  • Precision: 100% (no false positives)
  • Recall: 70%

Key Features

Hybrid Approach: VLM name extraction + CV detection + VLM verification Name-Based: Signatures saved as signature_周寶蓮.png No False Positives: Name-specific verification filters out dates, text, stamps Duplicate Prevention: Only one signature per person Handles Both: PDFs with/without text layer

File Structure

extract_pages_from_csv.py          # Step 1: Extract pages
extract_signatures_hybrid.py       # Step 2: Extract signatures (CURRENT)
README.md                          # This file
PROJECT_DOCUMENTATION.md           # Complete documentation
README_page_extraction.md          # Page extraction guide
README_hybrid_extraction.md        # Signature extraction guide

Requirements

Data

  • Input: /Volumes/NV2/PDF-Processing/master_signatures.csv (86,073 rows)
  • PDFs: /Volumes/NV2/PDF-Processing/total-pdf/batch_*/
  • Output: /Volumes/NV2/PDF-Processing/signature-image-output/

Status

Page extraction: Tested with 100 files, working Signature extraction: Tested with 5 files, 70% recall, 100% precision Large-scale testing: Pending Full dataset (86K files): Pending

See PROJECT_DOCUMENTATION.md for complete details.

S
Description
Automated extraction of handwritten Chinese signatures from PDF documents using hybrid VLM + Computer Vision approach. 70% recall, 100% precision.
Readme 6.9 MiB
Languages
Python 100%