---
license: cc-by-nc-4.0
pretty_name: "IRIS: Inverse Recovery and Identification of Physical Dynamic Systems"
task_categories:
  - video-classification
  - other
tags:
  - physics
  - video
  - benchmark
  - parameter-estimation
  - inverse-problems
  - dynamical-systems
  - eccv
size_categories:
  - n<1K
viewer: false
configs:
  - config_name: default
    data_files:
      - split: train
        path: "*/*/*.mp4"
---

# IRIS: A Real-World Benchmark for Inverse Recovery and Identification of Physical Dynamic Systems from Monocular Video

**IRIS** is a real-world benchmark of **240 high-resolution (3840×2160, 60 fps) videos** spanning **8 physical dynamics classes**, covering both **single-body** and **multi-body** systems. Each setting is recorded with repeated takes and ships with **independently measured ground-truth physical parameters**, enabling standardized evaluation of inverse parameter recovery and equation-family identification from monocular video.

Introduced in our ECCV 2026 paper. Project page: https://kurbanintelligencelab.github.io/iris-benchmark.github.io/

## Dataset at a glance

- **240 videos** = 8 classes × 3 settings × 10 repeated takes
- **Resolution:** 3840×2160 (4K), 60 fps
- **Ground truth:** physical parameters per (class, setting) in [`parameters.json`](parameters.json), with `mean`, `std`, `min`, `max` per parameter

## Classes

| Type | Class | Settings | Videos | Description |
|---|---|---|---|---|
| Single | `dropping_ball` | `drop_50`, `drop_100`, `drop_150` | 30 | Same ball released from rest under gravity (drop height in cm) |
| Single | `falling_ball` | `small`, `mid`, `big` | 30 | Free-falling balls of different sizes |
| Single | `sliding_cone` | `cone_45`, `cone_60`, `cone_80` | 30 | Cone sliding on an inclined surface (incline angle in °) |
| Single | `pendulum` | `pendulum_20`, `pendulum_45`, `pendulum_90` | 30 | Single pendulum (initial angle in °) |
| Single | `rotation` | `slow`, `mid`, `fast` | 30 | Rotating cone of different speed, fixed camera |
| Multi | `hitting_cones` | `slow`, `mid`, `fast` | 30 | Ball colliding with a pyramid of cones (contact / momentum transfer) |
| Multi | `two_moving_pendulums` | `pendulum_20`, `pendulum_45`, `pendulum_90` | 30 | Two pendulums released from the same angle, colliding |
| Multi | `two_moving_pendulum_one_static` | `pendulum_20`, `pendulum_45`, `pendulum_90` | 30 | One moving pendulum strikes a static one |
| | **Total** | **24 settings** | **240** | |

## Directory structure

```
IRIS/
├── parameters.json                 # Ground-truth physical parameters
├── IRIS_images/                    # Representative preview frames (5 per class + figures)
├── Dropping_ball/
│   ├── drop_50/   {01..10}.mp4
│   ├── drop_100/  {01..10}.mp4
│   └── drop_150/  {01..10}.mp4
├── Falling_ball/        {big,mid,small}/        {01..10}.mp4
├── Hitting_cones/       {slow,mid,fast}/        {01..10}.mp4
├── Pendulum/            {pendulum_20,45,90}/    {01..10}.mp4
├── Rotation/            {slow,mid,fast}/        {01..10}.mp4
├── Sliding_cone/        {cone_45,60,80}/        {01..10}.mp4
├── Two_Moving_Pendulums/              {pendulum_20,45,90}/  {01..10}.mp4
└── Two_Moving_Pendulum_One_Static/   {pendulum_20,45,90}/  {01..10}.mp4
```

> Folder names are capitalized (e.g. `Dropping_ball`); the keys in `parameters.json` are lowercase (e.g. `dropping_ball`).

## Ground truth (`parameters.json`)

Each `(class, setting)` entry maps physical quantities to their measured statistics:

```json
"pendulum": {
  "pendulum_45": {
    "angle":          { "mean": 45.0, "std": 0.0, "min": 45.0, "max": 45.0 },
    "rope_length":    { "mean": 0.50, "std": 0.0, "min": 0.50, "max": 0.50 },
    "camera_to_cable":{ "mean": 0.96, "std": 0.0, "min": 0.96, "max": 0.96 }
  }
}
```

Settings are fixed by design, so `std = 0` and `min = max = mean`. Distances are in meters, angles in degrees.

| Class | Parameters |
|---|---|
| `dropping_ball` | `drop_height`, `camera_to_horizontal` |
| `falling_ball` | `drop_height`, `ball_radius`, `gravity` |
| `sliding_cone` | `angle`, `hypotenuse`, `vertical_cathetus`, `horizontal_cathetus`, `camera_to_object`, `camera_height` |
| `pendulum` | `angle`, `rope_length`, `camera_to_cable` |
| `rotation` | `camera_to_object` |
| `hitting_cones` | `ball_to_cones`, `camera_to_cones` |
| `two_moving_pendulums` | `angle`, `rope_length_1`, `rope_length_2`, `camera_to_pendulum` |
| `two_moving_pendulum_one_static` | `angle`, `rope_length_1`, `rope_length_2`, `camera_to_pendulum` |

## Usage

```bash
pip install huggingface_hub
huggingface-cli download rasulkhanbayov/IRIS --repo-type dataset --local-dir ./IRIS
```

```python
import json
from huggingface_hub import snapshot_download

local = snapshot_download(repo_id="rasulkhanbayov/IRIS", repo_type="dataset")
params = json.load(open(f"{local}/parameters.json"))
print(params["pendulum"]["pendulum_45"])
```

## License

Released under **CC-BY-NC-4.0** (Creative Commons Attribution-NonCommercial 4.0). Free for non-commercial research use with attribution.

## Citation

```bibtex
@inproceedings{khanbayov2026iris,
  title     = {{IRIS}: A Real-World Benchmark for Inverse Recovery and Identification
               of Physical Dynamic Systems from Monocular Video},
  author    = {Khanbayov, Rasul and Barhdadi, Mohamed Rayan and
               Serpedin, Erchin and Kurban, Hasan},
  booktitle = {Proceedings of the European Conference on Computer Vision (ECCV)},
  year      = {2026}
}
```