Sci-Figure — Scientific Figure Extractor
Precisely extract figures and sub-figures from academic PDF papers.
Script Directory
Scripts in scripts/ subdirectory. Replace ${SKILL_DIR} with this SKILL.md's directory path.
| Script | Purpose |
|---|---|
scripts/extract_figure.py | Main CLI for figure extraction |
Preferences (EXTEND.md)
Use Bash to check EXTEND.md existence (priority order):
# Check project-level first
test -f .baoyu-skills/Sh_Sci_Fig/EXTEND.md && echo "project"
# Then user-level (cross-platform: $HOME works on macOS/Linux/WSL)
test -f "$HOME/.baoyu-skills/Sh_Sci_Fig/EXTEND.md" && echo "user"EXTEND.md Supports: Default DPI | Default output format | Tesseract path
Usage
python ${SKILL_DIR}/scripts/extract_figure.py <input.pdf> [options]Options
| Option | Short | Description | Default |
|---|---|---|---|
<input> | PDF file path | Required | |
--figure | -f | Figure number (1, 2, 3...) | Required (except --list/--all) |
--subfigure | -s | Sub-figure label (a, b, c...) | None (returns whole figure) |
--output | -o | Output directory | Current directory |
--dpi | -d | Output resolution | 600 |
--list | -l | List all available figure numbers | false |
--all | Extract all figures | false | |
--format | Output format | png |
Examples
# Extract Figure 2, sub-figure c
python ${SKILL_DIR}/scripts/extract_figure.py paper.pdf -f 2 -s c
# Extract entire Figure 3
python ${SKILL_DIR}/scripts/extract_figure.py paper.pdf -f 3
# List all available figures in a PDF
python ${SKILL_DIR}/scripts/extract_figure.py paper.pdf --list
# Extract all figures
python ${SKILL_DIR}/scripts/extract_figure.py paper.pdf --all
# Custom output directory and DPI
python ${SKILL_DIR}/scripts/extract_figure.py paper.pdf -f 2 -s c -o ./output/ -d 300Output:
Extracted: figure_2c.png (1920x1080, 600 DPI)Error Handling
| Scenario | Behavior |
|---|---|
| Figure number not found | Error + list all available figure numbers |
| OCR recognition failed | Return entire figure region |
| Sub-figure split failed | Return entire figure region |
| No sub-figure labels found | Return entire figure region |
Tech Stack
| Library | Role |
|---|---|
| pdfplumber | Text + coordinate extraction (locate "Figure X" labels) |
| PyMuPDF (fitz) | PDF → high-quality image rendering (600 DPI) |
| opencv-python | Boundary detection, contour analysis |
| Pillow | Final cropping, format conversion |
| pytesseract | OCR for sub-figure label recognition |
Detected Figure Fields
| Field | Type | Description |
|---|---|---|
number | int | Figure number |
page | int | Page index (0-based) |
bbox | tuple | Crop region in pixels |
bbox_pdf | tuple | Crop region in PDF points |
caption | str | Caption text (truncated to 200 chars) |
caption_full | str | Full caption text (no truncation) |
caption_bbox_pdf | tuple | Caption bounding box in PDF points |
sublabels | list[str] | Sub-figure labels, e.g. ["a","b","c"] |
sublabel_details | list[dict] | Labels with detected format, e.g. {"label":"a","format":"(a)"} |
figure_type | str | One of: figure, scheme, chart, supplementary, extended_data |
is_supplementary | bool | True for supplementary and extended_data types |
image | ndarray | Cropped figure image (numpy array) |
Extension Support
Custom configurations via EXTEND.md. See Preferences section for paths and supported options.
© License & Copyright
Aut_Sci_Write — Autonomous Scientific Writer
- Author: Shuo Zhao
- License: MIT License
- Copyright: © 2026 Shuo Zhao. All rights reserved.
- Original Work: This is an original work created by the author. No reproduction, redistribution, or commercial use without explicit permission. Permission is hereby granted, free of charge, to any person obtaining a copy of this software... (See the LICENSE file in the root directory for the full MIT terms.)