---
license: other
task_categories:
  - robotics
tags:
  - robotics
  - dexterous-manipulation
  - teleoperation
  - motion-capture
  - human-hand
  - imitation-learning
  - hdf5
size_categories:
  - 10GB
---

# CAP — Dexterous Manipulation Capture Dataset (Cups Ordering, Right Hand)

CAP is a **human hand motion capture + dexterous manipulation demonstration** dataset. It records an operator performing the **cups ordering (`cups_order`)** task with the **right hand**. Data is captured with a DexCap-style pipeline and ships both **compressed trajectory HDF5 files** and **raw multi-view camera frames**, ready for motion retargeting, imitation learning, and hand-pose analysis.

- Repo: `dex-robot/cap`
- Main file: `cap.zip` (10,697,737,890 bytes ≈ 9.96 GiB)
- Contents: 18,939 files + 24 directory entries
- SHA256: `f91c11ee1761822fa875d4783c1fd9388f6fa3f0fa3feeef6cd5c20775220c10`
- Capture date: 2026-07-07
- Task: cups ordering
- Hand: right

---

## 1. Overview

| Item | Value |
| --- | --- |
| Task | `cups_order` (ordering cups) |
| Hand | Right |
| Capture date | 2026-07-07 |
| Recordings | 5 (16:46:34 / 16:54:35 / 16:56:54 / 16:59:04 / 17:01:24) |
| Trajectory files | 5 × `.hdf5` (one per recording) |
| Camera views | 6 (left hand / right hand / head stereo / head global RGB / head global depth) |
| Image frames | 18,914 × `.png` + 5 × `.mp4` |
| Other assets | 3 × `.json`, 6 × `.txt`, 5 × `.npy`, 1 × `.raw` |
| Archive size | 10.7 GB (10,697,737,890 bytes) |

---

## 2. Directory Layout

```
cap/
├── hdf5/                                   # one compressed trajectory per recording
│   ├── cups_order_right_hand_20260707_164634/
│   │   └── cups_order_right_hand_20260707_164634.hdf5
│   ├── cups_order_right_hand_20260707_165435/
│   │   └── cups_order_right_hand_20260707_165435.hdf5
│   ├── cups_order_right_hand_20260707_165654/
│   │   └── cups_order_right_hand_20260707_165654.hdf5
│   ├── cups_order_right_hand_20260707_165904/
│   │   └── cups_order_right_hand_20260707_165904.hdf5
│   └── cups_order_right_hand_20260707_170124/
│       └── cups_order_right_hand_20260707_170124.hdf5
└── raw_data/                               # raw multimodal stream (images + video + calibration)
    └── cups_order_right_hand_20260707_164634/
        └── cups_order_right_hand_20260707_164634_extracted/
            └── observe/
                └── vision/
                    ├── left_hand_rgb/            # left wrist view (video + metadata)
                    ├── right_hand_rgb/           # right wrist view
                    ├── head_zed_left/            # head ZED left
                    ├── head_zed_right/           # head ZED right
                    ├── head_global_rgb/          # head global RGB
                    ├── head_global_depth/        # head global depth
                    └── *_frames/                 # extracted PNG sequences per view
```

---

## 3. Recording Sessions

| Session ID | Start time | HDF5 trajectory | Raw frames |
| --- | --- | --- | --- |
| `cups_order_right_hand_20260707_164634` | 16:46:34 | ✅ | ✅ |
| `cups_order_right_hand_20260707_165435` | 16:54:35 | ✅ | — |
| `cups_order_right_hand_20260707_165654` | 16:56:54 | ✅ | — |
| `cups_order_right_hand_20260707_165904` | 16:59:04 | ✅ | — |
| `cups_order_right_hand_20260707_170124` | 17:01:24 | ✅ | — |

> Note: the full multi-view raw frames (18,915 PNG + 5 MP4) are published with the **first session** `164634`; the other four recordings ship as compressed HDF5 trajectories.

---

## 4. Camera Views & Frame Counts

| View directory | PNG frames | Video |
| --- | --- | --- |
| `head_global_depth_frames` | 5,565 | ✅ |
| `right_hand_rgb_frames` | 3,089 | ✅ |
| `head_zed_right_frames` | 2,629 | ✅ |
| `left_hand_rgb_frames` | 2,563 | ✅ |
| `head_zed_left_frames` | 2,546 | ✅ |
| `head_global_rgb_frames` | 2,522 | ✅ |

Frames are named `frame_%06d.png`, but the indices are **not strictly contiguous** (frames were dropped during capture). Always use the sorted filename order; do not assume `i` and `i+1` are adjacent.

### Preview

![Six views overview](preview_overview.png)

![Six views synced GIF](preview_grid.gif)

| Preview file | Content |
| --- | --- |
| `preview_overview.png` | single-frame overview of all 6 views |
| `preview_grid.gif` | all 6 views in sync (24 frames) |
| `preview_right_hand_rgb.gif` | right wrist view |
| `preview_head_global_rgb.gif` | head global RGB |
| `preview_head_global_depth.gif` | head global depth |

---

## 5. Download

### 5.1 huggingface-cli (recommended, resumable)

```bash
pip install -U "huggingface_hub[cli]"
export HF_ENDPOINT=https://hf-mirror.com        # optional mirror for CN networks
huggingface-cli download dex-robot/cap cap.zip --repo-type dataset --local-dir ./cap_data
```

### 5.2 Python

```python
from huggingface_hub import hf_hub_download
p = hf_hub_download("dex-robot/cap", "cap.zip", repo_type="dataset")
print(p)
```

### 5.3 Direct URL

```
https://huggingface.co/datasets/dex-robot/cap/resolve/main/cap.zip
```

---

## 6. Extract & Verify

```bash
# 1) size
stat -c %s cap.zip        # expected: 10697737890

# 2) SHA256
sha256sum cap.zip
# f91c11ee1761822fa875d4783c1fd9388f6fa3f0fa3feeef6cd5c20775220c10

# 3) CRC check (all 18963 entries must report OK)
unzip -t cap.zip

# 4) extract -> cap/
unzip -q cap.zip

du -sh cap
```

Expected:

```
cap/
├── hdf5/      (5 .hdf5 files)
└── raw_data/  (18,934 files)
```

---

## 7. Usage

### 7.1 Read an HDF5 trajectory

```python
import h5py

path = "cap/hdf5/cups_order_right_hand_20260707_164634/cups_order_right_hand_20260707_164634.hdf5"
with h5py.File(path, "r") as f:
    def show(name, obj):
        if isinstance(obj, h5py.Dataset):
            print(f"D {name:50s} shape={obj.shape} dtype={obj.dtype}")
        else:
            print(f"G {name}")
    f.visititems(show)
```

### 7.2 Read image frames

```python
import cv2, glob

frames = sorted(glob.glob(
    "cap/raw_data/cups_order_right_hand_20260707_164634/"
    "cups_order_right_hand_20260707_164634_extracted/observe/vision/"
    "head_global_rgb_frames/frame_*.png"))
print("frames:", len(frames))
img = cv2.imread(frames[0])
print(img.shape)  # (H, W, 3)
```

---

## 8. Recommended Environment

```bash
pip install h5py opencv-python numpy
```

- Python ≥ 3.8
- ~15 GB free disk after extraction (raw PNG sequences are large)
- `head_global_depth` may be 16-bit PNG or accompanied by `.npy` / `.raw` raw depth

---

## 9. License & Citation

- License: see the repo `LICENSE`; contact the publisher if unspecified.

```bibtex
@misc{cap_dataset_2026,
  title  = {CAP: Cups Ordering Dexterous Manipulation Capture Dataset (Right Hand)},
  author = {dex-robot},
  year   = {2026},
  howpublished = {\url{https://huggingface.co/datasets/dex-robot/cap}}
}
```

---

## 10. FAQ

**Q: Download interrupted?**
`huggingface-cli download` resumes automatically — just re-run the same command. Add `--max-workers 1` for a more stable (slower) transfer.

**Q: `unzip` says "End-of-central-directory signature not found"?**
The download is incomplete / truncated. Check that the size is exactly **10,697,737,890 bytes** and the SHA256 matches; if not, re-download.

**Q: I only need trajectories, not the 10 GB of images?**
Currently only the full bundle is published. Open a Discussion if you need a split release.

**Q: How do I align depth with RGB?**
`*_frames` and the MP4 of the same view share frame indices (`frame_%06d`). Cross-view alignment: use the calibration JSON under `raw_data/.../observe/vision/`.

---

## 11. Known Limitations

1. **Frame indices are not contiguous.** Each view's `frame_%06d.png` has gaps (frames dropped during capture) — e.g. `right_hand_rgb_frames` holds 3,089 frames with a max index of 3,746. Use sorted filename order; never infer the next frame as `i+1`.
2. **Raw frames cover the first session only.** Of the 5 recordings, only `164634` ships full multi-view PNG / MP4; the other four provide HDF5 trajectories only.
3. **HDF5 internal layout may evolve across capture versions.** Group / dataset names can differ between recordings — inspect the structure with `visititems` before reading arrays.
4. The archive was recovered from an interrupted packing process and passes CRC verification for all 18,963 entries; one incomplete trailing PNG frame was dropped.