What is BANOS?

BANOS is a set of metrics for evaluating algorithmic behavior annotations against a ground truth (typically human annotations). It is designed for ethology and computer vision workflows where researchers annotate behaviors in video data.

Traditional frame-based metrics (precision/recall/F1) capture detection accuracy but miss important temporal qualities: does the predicted segment overlap well with the ground-truth bout? Does the prediction start and end at the right time? Is the prediction internally consistent, or does it flicker on and off inside the bout?

BANOS addresses these questions with four complementary metrics.

The 4 BANOS Metrics

1. Detection Accuracy (DA) — Precision, Recall, and F1 score over matched behavioral segments (TP/FP/FN at the bout level).

2. Segment Overlap (SO) — Temporal Intersection over Union (tIoU) between each matched predicted segment and its ground-truth counterpart.

3. Temporal Precision (TP) — Penalizes start/end time errors: 1 / (1 + |start deviation| + |end deviation|).

4. Intra-bout Continuity (IC) — Measures label stability inside each ground-truth bout: 1 - (label switches / bout length).

Installation

pip install banos

Requires Python 3.11+. Core dependency: pandas. Optional: scipy (for matching='optimal').

Quick Start

import banos
import pandas as pd

# Load annotations as DataFrames (rows=frames, columns=behaviors, values=0/1)
pred = pd.read_csv("machine_annotations.csv")
gt   = pd.read_csv("human_annotations.csv")

# Score a single recording
metrics = banos.score(pred, gt)
# {'behavior1': {'precision': 0.9, 'recall': 0.85, 'f1_score': 0.87,
#                'so': 0.76, 'tp': 0.82, 'ic': 0.91}, ...}

# Score multiple recordings
group_metrics, overall_metrics = banos.score({
    'recording_1': (pred_1, gt_1),
    'recording_2': (pred_2, gt_2),
})

banos.score() returns:

• Single recording: dict[behavior → dict[metric → float]]
• Multiple recordings: (per-recording metrics, overall averaged metrics)

Absent-behavior scoring (v0.2.0): when a behavior has no ground-truth bouts, BANOS checks whether the machine also predicted nothing — if so, all metrics = 1.0 (correct absence); if the machine predicted bouts that don't exist in GT, all metrics = 0.0 (false detection). This is excluded from NaN-averaging correctly.

Examples & Tutorials

Advanced Usage

Optimal Matching

By default, predicted segments are matched to ground-truth bouts greedily (by overlap). For a globally optimal assignment, use the Hungarian algorithm:

metrics = banos.score(pred, gt, matching='optimal')

Requires scipy (pip install scipy).

Lower-level API

from banos import preprocess_data, calculate_banos_for_each_file, aggregate_metrics

data_dict = {
    'file1': (pred_df_1, gt_df_1),
    'file2': (pred_df_2, gt_df_2),
}

preprocessed, dropped = preprocess_data(data_dict)
per_file_metrics      = calculate_banos_for_each_file(preprocessed)
group_metrics, overall = aggregate_metrics(per_file_metrics)

MATLAB

A MATLAB implementation is provided in matlab/BANOS/. Usage mirrors the Python API.

% Add toolbox to path
run('matlab/BANOS/setup.m');

% Score a single recording (pred/gt = cell arrays: row 1 = headers, rows 2+ = binary data)
metrics = BANOS_score(pred, gt);

% Score multiple recordings
dataStruct.Recording_1 = {pred1, gt1};
dataStruct.Recording_2 = {pred2, gt2};
[groupMetrics, overallMetrics] = BANOS_score(dataStruct);

See demo/tutorial_matlab.m for a full walkthrough.

Also available on MATLAB File Exchange.

Contributing

BANOS is functionally complete by design. We welcome bug reports and documentation improvements. See CONTRIBUTING.md for details on how to report issues, submit fixes, and the project's maintenance lifecycle.

To report a security vulnerability, see SECURITY.md — please do not use public GitHub Issues for security reports.

Citation

If you use BANOS, please cite:

Chindemi G., Bellone C., Girard B. From eye to AI: studying rodent social behavior in the era of machine learning. arXiv:2508.04255 (2025). https://doi.org/10.48550/arXiv.2508.04255

@article{chindemi2025eye,
  title   = {From eye to {AI}: studying rodent social behavior in the era of machine learning},
  author  = {Chindemi, Giuseppe and Bellone, Camilla and Girard, Benoit},
  journal = {arXiv preprint arXiv:2508.04255},
  year    = {2025},
  doi     = {10.48550/arXiv.2508.04255}
}

Changelog

See CHANGELOG.md for release history.

License

MIT — see LICENSE.