gbanyan cb77f481ec Paper A v3.18.1: address remaining partner red-pen prose clarity items
Three targeted fixes per partner's red-pen audit (residue from v3.18 cleanup):

1. III-D 92.6% match rate -- partner red-circled the bare figure ("不太懂改善線").
   Add explicit explanation of the unmatched 7.4% (13,573 signatures): they
   could not be matched to a registered CPA name (deviation from two-signature
   layout, OCR-name mismatch) and are excluded from same-CPA pairwise analyses
   for definitional reasons, not discarded as noise.

2. III-I.1 Hartigan dip-test wording -- partner wrote "?所以為何?" next to the
   "rejecting unimodality is consistent with but does not directly establish
   bimodality" sentence. Replace with a direct three-line explanation: the
   test asks "is the distribution single-peaked?", a non-significant p means
   we cannot reject single-peak, a significant p means more than one peak
   (could be 2/3/...). Removes the partner's confusion without losing rigor.

3. IV-G validation lead-in -- partner wrote "不太懂為何陳述?" on the
   tangled "consistency check / threshold-free / operational classifier"
   triple. Rewrite as a three-bullet structure that names the *informative
   quantity* in each subsection (temporal trend / concentration ratio /
   cross-firm gap) and states explicitly why each is robust to cutoff choice.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-04-27 17:48:59 +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%