DataFlow-CV

🌊 Everything your model doesn't do. Analyse, convert, visualize, evaluate — a single CLI for all CV data.

A computer vision dataset processing library — analyse, convert, visualize, and evaluate annotations across YOLO, LabelMe, and COCO formats.

📦 Installation

pip install dataflow-cv               # from PyPI
pip install dataflow-cv[coco]         # optional: COCO RLE + evaluation

Or from source:

git clone https://github.com/zjykzj/DataFlow-CV.git
cd DataFlow-CV && pip install .

🚀 Quick Start

Command-line Interface

All required parameters (image directories, label directories, class files, output paths) are positional arguments for better usability. Use --help on any subcommand for detailed usage.

🔍 Dataset Analysis

# Dataset statistics (auto-detects YOLO / LabelMe / COCO)
dataflow-cv analyse stats yolo_labels/ --image-dir images/ --class-file classes.txt
dataflow-cv analyse stats labelme_json/
dataflow-cv analyse stats coco_annotations.json

# Train / test split (YOLO / LabelMe only — labels / images / both modes)
dataflow-cv analyse split -l yolo_labels/ outputs/ --ratio 0.8 --seed 42 -c classes.txt
dataflow-cv analyse split -i images/ outputs/ --ratio 0.8
dataflow-cv analyse split -l yolo_labels/ -i images/ outputs/ --ratio 0.8

# Category filter (keep a subset of categories, remap IDs per new classes.txt)
dataflow-cv analyse filter yolo_labels/ classes.txt classes_new.txt filtered/
dataflow-cv analyse filter coco_annotations.json classes.txt classes_new.txt filtered/

# N-way partition — YOLO / LabelMe only (labels drive, images follow by stem)
dataflow-cv analyse partition -n 4 --label-dir yolo_labels/ --image-dir images/ parts/
dataflow-cv analyse partition -n 4 --image-dir images/ --shuffle parts/

# File sampling — collect N files (random or sequential, labels / images / both modes)
dataflow-cv analyse sample -l yolo_labels/ output/ -n 10
dataflow-cv analyse sample -i images/ output/ -n 10 --no-shuffle
dataflow-cv analyse sample -l yolo_labels/ -i images/ output/ -n 5 --seed 42

# Sort by count descending (default: class ID ascending)
dataflow-cv analyse stats --sort-by count --descending yolo_labels/

# Verbose logging
dataflow-cv analyse stats --verbose yolo_labels/ --class-file classes.txt

🔄 Format Conversion

# YOLO → COCO
dataflow-cv convert yolo2coco images/ yolo_labels/ classes.txt output.json

# YOLO → COCO (with RLE encoding)
dataflow-cv convert yolo2coco images/ yolo_labels/ classes.txt output.json --do-rle

# YOLO → LabelMe
dataflow-cv convert yolo2labelme images/ yolo_labels/ classes.txt labelme_json/

# LabelMe → YOLO
dataflow-cv convert labelme2yolo labelme_json/ classes.txt yolo_labels/

# LabelMe → COCO
dataflow-cv convert labelme2coco labelme_json/ classes.txt output.json

# COCO → YOLO
dataflow-cv convert coco2yolo input.json yolo_labels/

# COCO → LabelMe
dataflow-cv convert coco2labelme input.json labelme_json/

# YOLO predictions → COCO (output: plain JSON list — prediction format)
dataflow-cv convert yolo2coco --prediction images/ yolo_preds/ classes.txt pred.json

# Options
dataflow-cv convert yolo2coco --verbose images/ labels/ classes.txt output.json
dataflow-cv convert yolo2coco --no-strict images/ labels/ classes.txt output.json

🎨 Visualization

# Visualize YOLO annotations
dataflow-cv visualize yolo images/ yolo_labels/ classes.txt --save visualized/

# Visualize LabelMe annotations
dataflow-cv visualize labelme images/ labelme_json/ --save visualized/

# Visualize COCO annotations
dataflow-cv visualize coco images/ coco_annotations.json --save visualized/

# Verbose logging + headless mode
dataflow-cv visualize yolo --verbose --no-display images/ yolo_labels/ classes.txt --save visualized/

📊 Evaluation

Evaluate object detection and instance segmentation models with COCO-standard metrics. Two COCO-format JSON files are required:

① Prepare Data

# GT: YOLO labels → COCO
dataflow-cv convert yolo2coco images/ yolo_labels/ classes.txt anno.json

# DT: YOLO predictions → COCO (add --prediction for model output)
dataflow-cv convert yolo2coco --prediction images/ yolo_preds/ classes.txt pred.json

⚠️ --prediction is required for YOLO prediction files — they have an extra confidence token per line. The flag outputs a plain JSON list (not a full COCO dict), which is the standard DT format for loadRes(). Only yolo2coco supports --prediction; labelme2coco does not need it (LabelMe has no label vs prediction distinction).

② Run Evaluation

# Object detection (bbox IoU)
dataflow-cv evaluate detection anno.json pred.json
dataflow-cv evaluate detection --verbose anno.json pred.json           # per-class breakdown
dataflow-cv evaluate detection --prf1 anno.json pred.json              # P/R/F1 only (skip mAP)
dataflow-cv evaluate detection --prf1 --prf1-iou 0.75 --prf1-method micro anno.json pred.json

# Instance segmentation (mask IoU)
dataflow-cv evaluate segmentation anno.json pred.json
dataflow-cv evaluate segmentation --verbose anno.json pred.json

# Save results as JSON
dataflow-cv evaluate detection --output results.json anno.json pred.json

# Custom log directory
dataflow-cv evaluate detection --verbose --log-dir logs/eval/ anno.json pred.json

③ Detection vs Segmentation

Two evaluation modes, distinguished by how overlap is measured:

• Object Detection — bounding box IoU. GT and DT require bbox; DT additionally requires score.
• Instance Segmentation — mask IoU. GT and DT require bbox, segmentation (polygon or RLE), and area; DT additionally requires score.

yolo2coco (label mode) and yolo2coco --prediction (prediction mode) automatically populate all required fields for both modes — no manual editing needed.

🐍 Python API

from dataflow.util.logging import LogConfig
from dataflow.analyse import StatsAnalyser, SplitAnalyser, FilterAnalyser, PartitionAnalyser, SampleAnalyser
from dataflow.convert import YoloAndCocoConverter
from dataflow.visualize import YOLOVisualizer
from dataflow.evaluate import DetectionEvaluator, compute_pr_f1

# ── Analyse ─────────────────────────────────────────
log_cfg = LogConfig(name="analyse", verbose=True)

# Dataset statistics
analyser = StatsAnalyser(log_config=log_cfg)
result = analyser.analyse("yolo_labels/", class_file="classes.txt")
print(f"{result.data.total_files} images, {result.data.total_annotations} objects")

# Train/test split (YOLO / LabelMe)
splitter = SplitAnalyser(log_config=log_cfg)
result = splitter.analyse(
    output_dir="output/", ratio=0.8, seed=42,
    label_dir="yolo_labels/", class_file="classes.txt",
)
print(f"Train: {result.data.train_count}, Val: {result.data.val_count}")

# Split with images (both mode — labels drive, images follow by stem)
result = splitter.analyse(
    output_dir="output/", ratio=0.8, seed=42,
    label_dir="yolo_labels/", image_dir="images/",
    class_file="classes.txt",
)

# Category filter (keep / remap categories per new classes.txt)
filterer = FilterAnalyser(log_config=log_cfg)
result = filterer.analyse(
    "yolo_labels/", original_class_file="classes.txt",
    new_class_file="classes_new.txt", output_dir="filtered/",
)

# N-way partition (YOLO / LabelMe labels; images follow by stem)
partitioner = PartitionAnalyser(log_config=log_cfg)
result = partitioner.analyse(
    output_dir="parts/", num=4,
    label_dir="yolo_labels/", image_dir="images/",
)

# File sampling (labels, images, or both — random or sequential)
sampler = SampleAnalyser(log_config=log_cfg)
result = sampler.analyse(
    output_dir="sampled/", count=10,
    label_dir="yolo_labels/", shuffle=True, seed=42,
)

# ── Convert ──────────────────────────────────────────
# YOLO labels → COCO (label mode)
log_cfg = LogConfig(name="convert", verbose=True)
converter = YoloAndCocoConverter(source_to_target=True, log_config=log_cfg, strict_mode=True)
result = converter.convert(
    source_path="yolo_labels/", target_path="anno.json",
    class_file="classes.txt", image_dir="images/",
)

# YOLO predictions → COCO (prediction mode)
converter = YoloAndCocoConverter(source_to_target=True, prediction=True)
result = converter.convert(
    source_path="yolo_preds/", target_path="pred.json",
    class_file="classes.txt", image_dir="images/",
)

# ── Visualize ────────────────────────────────────────
visualizer = YOLOVisualizer(
    label_dir="yolo_labels/", image_dir="images/",
    class_file="classes.txt", is_show=True, is_save=True,
    output_dir="visualized/", log_config=log_cfg,
)
result = visualizer.visualize()

# ── Evaluate ─────────────────────────────────────────
evaluator = DetectionEvaluator(log_config=LogConfig(name="eval", verbose=True))
result = evaluator.evaluate("anno.json", "pred.json")
print(f"AP: {result.metrics.ap:.3f}, AP50: {result.metrics.ap50:.3f}")

# Quick P/R/F1 at IoU=0.5 (default: macro averaging, bbox IoU)
prf1 = compute_pr_f1("anno.json", "pred.json", iou_threshold=0.5)
print(f"Macro F1: {prf1.overall.f1_score:.3f}")

# Micro averaging P/R/F1 (samples weighted equally)
prf1 = compute_pr_f1("anno.json", "pred.json", method="micro")
print(f"Micro F1: {prf1.overall.f1_score:.3f}")

# Segmentation P/R/F1 (mask IoU)
prf1 = compute_pr_f1("anno_segm.json", "pred_segm.json", iou_type="segm")
print(f"Segm F1: {prf1.overall.f1_score:.3f}")

📂 See the samples/ directory for complete examples: samples/analyse/ (statistics & split), samples/convert/ (6 conversion directions), samples/visualize/ (YOLO, LabelMe, COCO), samples/evaluate/ (detection & segmentation), samples/cli/ (CLI workflows).

🤖 AI Assistant Skills

We maintain a dedicated Claude Code skill for dataflow-cv — /dataflow:dataflow-cv — so LLMs and AI agents can operate its CLI and Python API correctly in any project. The skill covers:

• CLI command tree and task mapping: 16 subcommands across analyse / convert / visualize / evaluate
• Python API reference: handlers, analysers, converters, visualizers, evaluators
• Canonical example commands and known gotchas (coordinate semantics, prediction formats, RLE encoding, …)

Install once per machine:

claude plugin install dataflow@claude-skills

Once installed, AI assistants load the skill on demand when working on dataset conversion, evaluation, or similar tasks — it can also be invoked explicitly via /dataflow:dataflow-cv. The library works normally without it.

📖 Documentation

💡 Key Concepts

• Format-Native Coordinates: YOLO uses normalized [0,1] center-based coordinates; LabelMe and COCO use absolute pixel top-left. There is no hidden internal normalization — check DatasetAnnotations.format to interpret coordinate semantics.
• Strict Mode (default): Validation errors raise exceptions immediately. Disable with --no-strict (CLI) or strict_mode=False (API) to skip invalid annotations and continue.
• Verbose Logging: --verbose enables per-module file logging via LogManager — console shows INFO-level progress, log files capture DEBUG details. All logging is owned by modules; the CLI uses click.echo() for terminal output.
• Headless Support: Use --no-display for servers/Docker — pair with --save to render visualization images without a GUI window.
• Keyboard Shortcuts (visualization): ← / ↑ for previous, → / ↓ / Enter / Space for next, s to save snapshot, h to show hints, q / ESC to exit. First/last-image boundaries are no-ops. Title bar shows [N/T] position.
• Evaluation: --prf1 computes P/R/F1 only (single-threshold, per-class TP/FP/FN) — skips the full COCOeval mAP pipeline for speed. Supports macro/micro averaging and bbox/mask IoU. Run without --prf1 for standard COCO mAP. For both metrics, run twice.
• Prediction Files: YOLO predictions use 6 tokens (detection) or even tokens (segmentation) vs 5/odd for labels. Use --prediction with yolo2coco — outputs a plain JSON list of annotation dicts compatible with pycocotools loadRes().

🔧 Development

For detailed developer guidance including advanced test commands, debugging, and architecture overview, see CLAUDE.md. Optional Claude Code skills for common tasks (/maestro:spec, /maestro:commit, /maestro:release, /maestro:claude) are available via the maestro plugin — the project develops normally without them.

🧪 Testing

561 tests, 80% code coverage (5462 statements).

pytest                                    # All tests
pytest --cov=dataflow --cov-report=term   # With coverage
pytest tests/convert/test_yolo_and_coco.py  # Single module
pytest tests/evaluate/test_evaluator.py     # Single module

🎨 Code Quality

pip install -e .[dev]        # Install dev dependencies
black dataflow tests samples  # Format
isort dataflow tests samples  # Sort imports
mypy dataflow                 # Type check
flake8 dataflow tests samples # Lint

🔗 Pre-commit Hooks (Optional)

pip install pre-commit
pre-commit install            # Install git hooks (run once)

# After this, every `git commit` auto-runs:
#   black → isort → flake8 → whitespace checks

pre-commit run --all-files    # Manual run against all files

📁 Project Structure

dataflow/
├── label/           # Annotation handlers + data models
├── analyse/         # Dataset stats, train/val split, category filter, N-way partition, file sampling
├── convert/         # Format converters, RLE utility, log templates
├── visualize/       # OpenCV-based rendering, log templates
├── evaluate/        # pycocotools-based metrics, log templates
├── util/            # Unified logging (LogManager + format helpers)
└── cli/             # CLI entry point, commands, validation
tests/               # Unit & integration tests (561 tests, conftest fixtures)
samples/             # Python API usage examples (analyse, convert, visualize, evaluate, cli)
assets/              # Test data (det/seg by format)
specs/               # Canonical specifications (evaluate/ + formats/ + modules/)

🤝 Contributing

Contributions are welcome! Please review CLAUDE.md for architecture and development patterns before contributing.

1. 🍴 Fork the repository
2. 🌿 Create a feature branch
3. ✏️ Make your changes — spec-first: if a change affects a contract in specs/, update the spec before the code (SDD, see the /maestro:spec skill)
4. 🧪 Add or update tests as needed
5. ✅ Ensure code passes formatting and linting checks
6. 📬 Submit a pull request

📄 License

This project is licensed under the MIT License — see LICENSE for details.

🙏 Acknowledgments

• Thanks to the creators of YOLO, LabelMe, and COCO formats for establishing these annotation standards
• Built with OpenCV, NumPy, Click, and pycocotools
• Inspired by the need for seamless format conversion in multi-tool CV pipelines