Datasets:

thxplz
/

HowToEat

---
pretty_name: HowToEat
license: other
license_name: howtoeat-research-only
license_link: LICENSE.md
language:
  - en
task_categories:
  - object-detection
  - image-classification
tags:
  - hand-object-interaction
  - human-object-interaction
  - eating-action-recognition
  - dietary-assessment
  - food
  - face
size_categories:
  - 10K<n<100K
configs:
  - config_name: hand_object_detection
    default: true
    data_files:
      - split: train
        path: hand_object_detection/train-*
      - split: test
        path: hand_object_detection/test-*
  - config_name: eating_recognition
    data_files:
      - split: train
        path: eating_recognition/train-*
      - split: test
        path: eating_recognition/test-*
---
# HowToEat: Hand-Object Interaction and Eating Action in Eating Scenarios

**HowToEat** is an image dataset for analysing eating behaviour. It provides:

1. **Hand-object interaction + eating face detection** (`hand_object_detection`): **95,190 images** with **190,333 hand instances** (box, left/right side, contact state, and the box and category of the held object) and **151,620 face instances** (box, eating / not eating).
2. **Eating action recognition** (`eating_recognition`): **6,280 manually labelled faces** (eating / not eating) for image classification.

The images are frames from **6,701 publicly available eating videos** covering 12 eating and drinking scenarios.

- **Paper:** Yingcheng Wang, Junwen Chen, Keiji Yanai. *HowToEat: Exploring Human-Object Interaction and Eating Action in Eating Scenarios.* MADiMa '23 (8th International Workshop on Multimedia Assisted Dietary Management, in conjunction with ACM Multimedia 2023). [doi:10.1145/3607828.3617790](https://doi.org/10.1145/3607828.3617790)
- **Institution:** Department of Informatics, The University of Electro-Communications, Tokyo, Japan
- **License:** [HowToEat Research-Only License](LICENSE.md): non-commercial research and education only (see [License](#license))
- **Not included:** the source videos and the trained models are **not** released.

---

## Quick start

By downloading or using the dataset you agree to the [HowToEat Research-Only License](LICENSE.md).

```python
from datasets import load_dataset
# Task 1: hand-object interaction + eating face detection
det = load_dataset("thxplz/HowToEat", "hand_object_detection")
sample = det["train"][0]
sample["image"]          # PIL.Image (full frame)
sample["hands"]          # list of hand instances
sample["faces"]          # list of face instances
# Task 2: eating action recognition
rec = load_dataset("thxplz/HowToEat", "eating_recognition")
rec["train"][0]["face_crop"], rec["train"][0]["label"]   # 224x224 crop, 0 = eating
# Stream instead of downloading everything (~35 GB)
det_stream = load_dataset("thxplz/HowToEat", "hand_object_detection", split="test", streaming=True)
```

---

## Dataset structure

```
HowToEat/
├── hand_object_detection/       # Parquet shards (images embedded), Task 1
├── eating_recognition/          # Parquet shards (images embedded), Task 2
├── annotations/                 # the same annotations in the original JSON format
│   ├── detection_train.json     #   paper split
│   ├── detection_test.json
│   ├── detection_train_balanced.json   # balanced split (see "Splits")
│   ├── detection_test_balanced.json
│   ├── eating_recognition_train.json
│   └── eating_recognition_test.json
├── metadata/
│   └── categories.json          # id <-> name maps
├── LICENSE.md
└── README.md
```

Image files are identified by `file_name = "<verb>/<category>/<video_id>_<frame>.jpg"`, for example `eating/pizza/v3174_011858.jpg`. `<video_id>` is an **anonymous video ID** (`v0001` … `v6701`) and `<frame>` is the 6-digit frame index within that video. Frames with the same `video_id` come from the same video.

### Scene categories (12)

`hamburger`, `beer` (under `drinking/`), `bread`, `pizza`, `pasta`, `noodles`, `with_knife_and_fork`, `sushi`, `with_spoon`, `with_fork`, `sandwich`, `with_chopsticks`. All except `beer` are under `eating/`. The category describes the scene of the whole video; it is not a per-instance label.

### Config `hand_object_detection`

| Column | Type | Description |
|---|---|---|
| `image` | Image | Full frame, original JPEG. Sizes vary: 74% are 1920×1080, 14% 1280×720, 4% 3840×2160, and the rest other sizes, including some portrait frames (see `width` / `height`) |
| `file_name` | string | Key shared with the JSON annotations |
| `video_id` | string | Anonymous video ID (e.g. `v0123`) |
| `frame` | int | Frame index in the source video |
| `category` | ClassLabel (12) | Scene category of the video |
| `width`, `height` | int | Image size |
| `hands` | list of struct | One entry per hand, see below |
| `faces` | list of struct | One entry per face, see below |
| `split_balanced` | string | `"train"` / `"test"` in the balanced split (see [Splits](#splits)) |

`hands[i]`:

| Field | Description |
|---|---|
| `hand_box` | `[x_min, y_min, x_max, y_max]`, absolute pixels |
| `hand_side` | `0` = left, `1` = right |
| `ho_exist` | `1` = the hand is in contact with a portable object, `0` = no contact |
| `obj_box` | Box of the held object, `[]` when `ho_exist = 0` |
| `obj_cat` | Object category (table below), `-1` when `ho_exist = 0` |

`faces[j]`:

| Field | Description |
|---|---|
| `face_box` | `[x_min, y_min, x_max, y_max]`, absolute pixels |
| `eat` | `1` = eating, `0` = not eating |

Object categories (`obj_cat`):

| id | name | instances | id | name | instances |
|---|---|---|---|---|---|
| 0 | food | 58,720 | 7 | bottle | 6,282 |
| 1 | chopsticks | 34,663 | 8 | cup | 10,594 |
| 2 | fork | 9,268 | 9 | glass | 9,742 |
| 3 | spoon | 10,783 | 10 | can | 875 |
| 4 | knife | 12,098 | 11 | napkin | 7,598 |
| 5 | bowl | 3,656 | 12 | unknown | 19 |
| 6 | plate | 1,121 | −1 | (no contact) | 24,914 |

Example record (original JSON format in `annotations/detection_*.json`):

```json
{
  "file_name": "eating/pizza/v3174_011858.jpg",
  "hand_obj": [
    {"hand_box": [928, 406, 1062, 519], "hand_side": 0, "ho_exist": 1,
     "obj_box": [931, 391, 1005, 453], "obj_cat": 0},
    {"hand_box": [900, 417, 979, 550], "hand_side": 1, "ho_exist": 1,
     "obj_box": [922, 390, 1006, 478], "obj_cat": 0}
  ],
  "face": [{"face_box": [903, 264, 1057, 411], "eat": 1}]
}
```

(In the JSON files, the hand list is called `hand_obj` and the face list `face`.)

### Config `eating_recognition`
| Column | Type | Description |
|---|---|---|
| `image` | Image | Full frame the face was taken from |
| `face_crop` | Image | 224×224 square crop around `face_box` with 15% context (the crop used at test time in the paper) |
| `file_name`, `video_id`, `frame`, `category` | | As above |
| `face_box` | list[int] | `[x_min, y_min, x_max, y_max]` of the labelled face |
| `label` | ClassLabel | **`0` = eating, `1` = not_eating** |
> ⚠️ **Label polarity differs between the two configs.** In `eating_recognition`, `label = 0` means *eating*. In `hand_object_detection`, `eat = 1` means *eating*. We kept the conventions of the original training code for both.
---
## Splits
### `hand_object_detection`
The `train` / `test` splits of this config are the **split used in the paper** (baseline results below). No video appears in both splits. Because the split was made in category order, **the test set does not cover all categories**: hamburger, beer, bread, pizza, pasta, noodles and sandwich appear **only in train**.

For a test set that covers every category, we also provide a **balanced split**: a random 4:1 split by video, where each category has about 11–24% of its images in test. It is available as the `split_balanced` column and as `annotations/detection_*_balanced.json`. **No baseline results have been published on the balanced split.**

```python
from datasets import load_dataset, concatenate_datasets
det = load_dataset("thxplz/HowToEat", "hand_object_detection")
full = concatenate_datasets([det["train"], det["test"]])
train_bal = full.filter(lambda s: s == "train", input_columns="split_balanced")
test_bal  = full.filter(lambda s: s == "test",  input_columns="split_balanced")
```

| | Paper split (train / test) | Balanced split (train / test) |
|---|---|---|
| Images | 76,905 / 18,285 | 76,025 / 19,165 |
| Videos | 5,550 / 1,104 | 5,351 / 1,303 |
| Hands | 155,634 / 34,699 | 153,532 / 36,801 |
| Faces | 122,183 / 29,437 | 122,033 / 29,587 |

Images per category:

| Category | Total | Paper train | Paper test | Balanced train | Balanced test |
|---|---|---|---|---|---|
| hamburger | 19,239 | 19,239 | 0 | 15,520 | 3,719 |
| sushi | 15,843 | 2,799 | 13,044 | 12,511 | 3,332 |
| pizza | 14,221 | 14,221 | 0 | 11,820 | 2,401 |
| beer | 11,701 | 11,701 | 0 | 9,258 | 2,443 |
| noodles | 10,891 | 10,891 | 0 | 8,511 | 2,380 |
| bread | 7,644 | 7,644 | 0 | 6,081 | 1,563 |
| pasta | 7,465 | 7,465 | 0 | 5,664 | 1,801 |
| sandwich | 2,834 | 2,834 | 0 | 2,258 | 576 |
| with_chopsticks | 1,727 | 35 | 1,692 | 1,359 | 368 |
| with_spoon | 1,582 | 2 | 1,580 | 1,290 | 292 |
| with_knife_and_fork | 1,165 | 71 | 1,094 | 974 | 191 |
| with_fork | 878 | 3 | 875 | 779 | 99 |
| **Total** | **95,190** | **76,905** | **18,285** | **76,025** | **19,165** |

### `eating_recognition`
| Split | Faces | Eating | Not eating | Videos |
|---|---|---|---|---|
| train | 5,033 | 3,108 | 1,925 | 537 |
| test | 1,247 | 770 | 477 | 353 |
The split is stratified 4:1 within each (category, label) group, as in the paper. It was made **per image, not per video**, so 332 videos have frames in both train and test. Keep this in mind when you interpret test accuracy.
---
## Statistics (`hand_object_detection`, both splits combined)
- Hands: 190,333 (left 85,797 / right 104,536). In contact with an object: 165,419. No contact: 24,914.
- Faces: 151,620 (eating 69,251 / not eating 82,369). Every image has 1–5 faces. A few images contain faces but no annotated hands.
- Faces per image: 1 face 56,153 images · 2 faces 27,518 · 3 faces 7,142 · 4 faces 2,880 · 5 faces 1,497.
---
## Baseline results
Results reported in the paper on the **paper split** (test set), with mAP at IoU > 0.5 (see the paper §5.1 for the hand-object matching rule).
**SOV-STG-H2E-S** (multi-task, single model):
| Left hand: no contact | Left hand: portable object | Right hand: no contact | Right hand: portable object | **Hand-object mAP** | Face: not eating | Face: eating | **Face mAP** |
|---|---|---|---|---|---|---|---|
| 61.91 | 87.79 | 47.98 | 88.56 | **71.56** | 57.43 | 73.89 | **65.66** |
**Eating action recognition** (`eating_recognition`), ResNet-50 (ImageNet-1K pre-trained, fine-tuned): **86.4%** test accuracy.

The trained models are not released.

---

## How the dataset was built

1. **Video collection.** Eating and drinking videos were collected for 12 scenarios (e.g. eating hamburger, drinking beer, eating with a spoon). The videos themselves are not distributed.
2. **Frame extraction.** A PPDM hand-object interaction detector trained on 100DOH and a RetinaFace (ResNet-50) face detector were run at 1 frame per second. Frames where a hand-held object overlapped the mouth landmarks were kept: 99,903 frames.
3. **Eating labels for faces.** 6,280 face crops were labelled manually (eating / not eating). This is the `eating_recognition` config. A ResNet-50 classifier trained on them then labelled all faces automatically.
4. **Hand-object annotation.** An SOV-STG-Hand model (trained on 100DOH, re-categorised into *no contact* / *portable object*) produced hand, side, contact and object boxes. Object categories were added and all annotations were then **checked and corrected manually** with the VIA annotation tool. Frames that could not be annotated reliably were marked invalid.
5. **Filtering.** We removed images without faces, images with more than 5 faces, and images whose largest face is smaller than 400 px. Faces smaller than 300 px were removed. Together with the invalid frames, this reduced the 97,484 verified frames to 95,190 images.

Labelling rules for eating faces: a face is *eating* if the person is performing the act of eating (mouth open with food or utensil entering it, or the face clearly shows eating while an object covers the mouth). An object in front of a closed mouth counts as *not eating*. Images that cannot be judged were not labelled.

---

## Limitations and biases

- **Partly automatic labels.** Face boxes come from RetinaFace. Eating labels on detection faces come from a classifier, and hand-object boxes were pre-annotated by a model before manual checking. Some errors remain (see the paper, Fig. 6c).
- **Domain.** The videos are mostly eating vlogs filmed for an audience: frontal faces, often a single person, good lighting. The foods are limited to the 12 scenario categories, and the people and regions shown are not representative of the world population.
- **Boxes outside the image.** Some boxes extend beyond the image border (for example, negative coordinates for a face cut off at the top): 517 face boxes and 488 hand/object boxes in `hand_object_detection`, and 1,156 of the 6,280 face boxes in `eating_recognition` (these come directly from the face detector). They are kept exactly as used in the paper; clip them to `[0, width] × [0, height]` if your code requires it. `face_crop` is padded with black where the box leaves the image.
- **Category imbalance.** `unknown` (id 12) has only 19 instances and `can` 875. The `with_*` categories are much smaller than the food categories.
- **Paper split coverage.** See [Splits](#splits): the paper's test set covers only 5 of the 12 categories in meaningful numbers.

## Ethical considerations

The images show real, identifiable people taken from publicly available videos. The dataset is intended **only** for research on eating behaviour and dietary assessment. It must not be used for face recognition, identification, tracking or profiling of individuals (see the license).

**Removal requests.** If you appear in the dataset or own one of the source videos and want content removed, contact **`chen-j@mm.inf.uec.ac.jp`** with the `file_name` or `video_id`. We will remove it from this repository.

---

## License

The **annotations, metadata and scripts** are released under the **[HowToEat Research-Only License](LICENSE.md)**. In short:

- ✅ Non-commercial research and education
- ❌ Commercial use of any kind, including training commercial models
- ❌ Redistribution or re-hosting (a few example images in publications are fine)
- ❌ Face recognition, identification or surveillance
- 📌 Citation of the paper is required

The **images** are frames from publicly available online videos. Their copyright belongs to the original video owners, and the authors do not grant any rights to them. They are made available for research use only, to the extent permitted by applicable law.

---

## Citation

```bibtex
@inproceedings{wang2023howtoeat,
  title     = {{HowToEat}: Exploring Human Object Interaction and Eating Action in Eating Scenarios},
  author    = {Wang, Yingcheng and Chen, Junwen and Yanai, Keiji},
  booktitle = {Proceedings of the 8th International Workshop on Multimedia Assisted Dietary Management},
  series    = {MADiMa '23},
  pages     = {71--78},
  year      = {2023},
  publisher = {Association for Computing Machinery},
  address   = {New York, NY, USA},
  location  = {Ottawa, ON, Canada},
  doi       = {10.1145/3607828.3617790},
  url       = {https://doi.org/10.1145/3607828.3617790}
}
```

## Acknowledgments

This work was supported by JSPS KAKENHI Grant Numbers 21H05812, 22H00540, 22H00548, and 22K19808.

	---
	pretty_name: HowToEat
	license: other
	license_name: howtoeat-research-only
	license_link: LICENSE.md
	language:
	- en
	task_categories:
	- object-detection
	- image-classification
	tags:
	- hand-object-interaction
	- human-object-interaction
	- eating-action-recognition
	- dietary-assessment
	- food
	- face
	size_categories:
	- 10K<n<100K
	configs:
	- config_name: hand_object_detection
	default: true
	data_files:
	- split: train
	path: hand_object_detection/train-*
	- split: test
	path: hand_object_detection/test-*
	- config_name: eating_recognition
	data_files:
	- split: train
	path: eating_recognition/train-*
	- split: test
	path: eating_recognition/test-*
	---

	# HowToEat: Hand-Object Interaction and Eating Action in Eating Scenarios

	HowToEat is an image dataset for analysing eating behaviour. It provides:

	1. Hand-object interaction + eating face detection (`hand_object_detection`): 95,190 images with 190,333 hand instances (box, left/right side, contact state, and the box and category of the held object) and 151,620 face instances (box, eating / not eating).
	2. Eating action recognition (`eating_recognition`): 6,280 manually labelled faces (eating / not eating) for image classification.

	The images are frames from 6,701 publicly available eating videos covering 12 eating and drinking scenarios.

	- Paper: Yingcheng Wang, Junwen Chen, Keiji Yanai. HowToEat: Exploring Human-Object Interaction and Eating Action in Eating Scenarios. MADiMa '23 (8th International Workshop on Multimedia Assisted Dietary Management, in conjunction with ACM Multimedia 2023). [doi:10.1145/3607828.3617790](https://doi.org/10.1145/3607828.3617790)
	- Institution: Department of Informatics, The University of Electro-Communications, Tokyo, Japan
	- License: [HowToEat Research-Only License](LICENSE.md): non-commercial research and education only (see [License](#license))
	- Not included: the source videos and the trained models are not released.

	---

	## Quick start

	By downloading or using the dataset you agree to the [HowToEat Research-Only License](LICENSE.md).

	```python
	from datasets import load_dataset

	# Task 1: hand-object interaction + eating face detection
	det = load_dataset("thxplz/HowToEat", "hand_object_detection")
	sample = det["train"][0]
	sample["image"] # PIL.Image (full frame)
	sample["hands"] # list of hand instances
	sample["faces"] # list of face instances

	# Task 2: eating action recognition
	rec = load_dataset("thxplz/HowToEat", "eating_recognition")
	rec["train"][0]["face_crop"], rec["train"][0]["label"] # 224x224 crop, 0 = eating

	# Stream instead of downloading everything (~35 GB)
	det_stream = load_dataset("thxplz/HowToEat", "hand_object_detection", split="test", streaming=True)
	```

	---

	## Dataset structure

	```
	HowToEat/
	├── hand_object_detection/ # Parquet shards (images embedded), Task 1
	├── eating_recognition/ # Parquet shards (images embedded), Task 2
	├── annotations/ # the same annotations in the original JSON format
	│ ├── detection_train.json # paper split
	│ ├── detection_test.json
	│ ├── detection_train_balanced.json # balanced split (see "Splits")
	│ ├── detection_test_balanced.json
	│ ├── eating_recognition_train.json
	│ └── eating_recognition_test.json
	├── metadata/
	│ └── categories.json # id <-> name maps
	├── LICENSE.md
	└── README.md
	```

	Image files are identified by `file_name = "<verb>/<category>/<video_id>_<frame>.jpg"`, for example `eating/pizza/v3174_011858.jpg`. `<video_id>` is an anonymous video ID (`v0001` … `v6701`) and `<frame>` is the 6-digit frame index within that video. Frames with the same `video_id` come from the same video.

	### Scene categories (12)

	`hamburger`, `beer` (under `drinking/`), `bread`, `pizza`, `pasta`, `noodles`, `with_knife_and_fork`, `sushi`, `with_spoon`, `with_fork`, `sandwich`, `with_chopsticks`. All except `beer` are under `eating/`. The category describes the scene of the whole video; it is not a per-instance label.

	### Config `hand_object_detection`

	\| Column \| Type \| Description \|
	\|---\|---\|---\|
	\| `image` \| Image \| Full frame, original JPEG. Sizes vary: 74% are 1920×1080, 14% 1280×720, 4% 3840×2160, and the rest other sizes, including some portrait frames (see `width` / `height`) \|
	\| `file_name` \| string \| Key shared with the JSON annotations \|
	\| `video_id` \| string \| Anonymous video ID (e.g. `v0123`) \|
	\| `frame` \| int \| Frame index in the source video \|
	\| `category` \| ClassLabel (12) \| Scene category of the video \|
	\| `width`, `height` \| int \| Image size \|
	\| `hands` \| list of struct \| One entry per hand, see below \|
	\| `faces` \| list of struct \| One entry per face, see below \|
	\| `split_balanced` \| string \| `"train"` / `"test"` in the balanced split (see [Splits](#splits)) \|

	`hands[i]`:

	\| Field \| Description \|
	\|---\|---\|
	\| `hand_box` \| `[x_min, y_min, x_max, y_max]`, absolute pixels \|
	\| `hand_side` \| `0` = left, `1` = right \|
	\| `ho_exist` \| `1` = the hand is in contact with a portable object, `0` = no contact \|
	\| `obj_box` \| Box of the held object, `[]` when `ho_exist = 0` \|
	\| `obj_cat` \| Object category (table below), `-1` when `ho_exist = 0` \|

	`faces[j]`:

	\| Field \| Description \|
	\|---\|---\|
	\| `face_box` \| `[x_min, y_min, x_max, y_max]`, absolute pixels \|
	\| `eat` \| `1` = eating, `0` = not eating \|

	Object categories (`obj_cat`):

	\| id \| name \| instances \| id \| name \| instances \|
	\|---\|---\|---\|---\|---\|---\|
	\| 0 \| food \| 58,720 \| 7 \| bottle \| 6,282 \|
	\| 1 \| chopsticks \| 34,663 \| 8 \| cup \| 10,594 \|
	\| 2 \| fork \| 9,268 \| 9 \| glass \| 9,742 \|
	\| 3 \| spoon \| 10,783 \| 10 \| can \| 875 \|
	\| 4 \| knife \| 12,098 \| 11 \| napkin \| 7,598 \|
	\| 5 \| bowl \| 3,656 \| 12 \| unknown \| 19 \|
	\| 6 \| plate \| 1,121 \| −1 \| (no contact) \| 24,914 \|

	Example record (original JSON format in `annotations/detection_*.json`):

	```json
	{
	"file_name": "eating/pizza/v3174_011858.jpg",
	"hand_obj": [
	{"hand_box": [928, 406, 1062, 519], "hand_side": 0, "ho_exist": 1,
	"obj_box": [931, 391, 1005, 453], "obj_cat": 0},
	{"hand_box": [900, 417, 979, 550], "hand_side": 1, "ho_exist": 1,
	"obj_box": [922, 390, 1006, 478], "obj_cat": 0}
	],
	"face": [{"face_box": [903, 264, 1057, 411], "eat": 1}]
	}
	```

	(In the JSON files, the hand list is called `hand_obj` and the face list `face`.)

	### Config `eating_recognition`

	\| Column \| Type \| Description \|
	\|---\|---\|---\|
	\| `image` \| Image \| Full frame the face was taken from \|
	\| `face_crop` \| Image \| 224×224 square crop around `face_box` with 15% context (the crop used at test time in the paper) \|
	\| `file_name`, `video_id`, `frame`, `category` \| \| As above \|
	\| `face_box` \| list[int] \| `[x_min, y_min, x_max, y_max]` of the labelled face \|
	\| `label` \| ClassLabel \| `0` = eating, `1` = not_eating \|

	> ⚠️ Label polarity differs between the two configs. In `eating_recognition`, `label = 0` means eating. In `hand_object_detection`, `eat = 1` means eating. We kept the conventions of the original training code for both.

	---

	## Splits

	### `hand_object_detection`

	The `train` / `test` splits of this config are the split used in the paper (baseline results below). No video appears in both splits. Because the split was made in category order, the test set does not cover all categories: hamburger, beer, bread, pizza, pasta, noodles and sandwich appear only in train.

	For a test set that covers every category, we also provide a balanced split: a random 4:1 split by video, where each category has about 11–24% of its images in test. It is available as the `split_balanced` column and as `annotations/detection__balanced.json`. No baseline results have been published on the balanced split.*

	```python
	from datasets import load_dataset, concatenate_datasets
	det = load_dataset("thxplz/HowToEat", "hand_object_detection")
	full = concatenate_datasets([det["train"], det["test"]])
	train_bal = full.filter(lambda s: s == "train", input_columns="split_balanced")
	test_bal = full.filter(lambda s: s == "test", input_columns="split_balanced")
	```

	\| \| Paper split (train / test) \| Balanced split (train / test) \|
	\|---\|---\|---\|
	\| Images \| 76,905 / 18,285 \| 76,025 / 19,165 \|
	\| Videos \| 5,550 / 1,104 \| 5,351 / 1,303 \|
	\| Hands \| 155,634 / 34,699 \| 153,532 / 36,801 \|
	\| Faces \| 122,183 / 29,437 \| 122,033 / 29,587 \|

	Images per category:

	\| Category \| Total \| Paper train \| Paper test \| Balanced train \| Balanced test \|
	\|---\|---\|---\|---\|---\|---\|
	\| hamburger \| 19,239 \| 19,239 \| 0 \| 15,520 \| 3,719 \|
	\| sushi \| 15,843 \| 2,799 \| 13,044 \| 12,511 \| 3,332 \|
	\| pizza \| 14,221 \| 14,221 \| 0 \| 11,820 \| 2,401 \|
	\| beer \| 11,701 \| 11,701 \| 0 \| 9,258 \| 2,443 \|
	\| noodles \| 10,891 \| 10,891 \| 0 \| 8,511 \| 2,380 \|
	\| bread \| 7,644 \| 7,644 \| 0 \| 6,081 \| 1,563 \|
	\| pasta \| 7,465 \| 7,465 \| 0 \| 5,664 \| 1,801 \|
	\| sandwich \| 2,834 \| 2,834 \| 0 \| 2,258 \| 576 \|
	\| with_chopsticks \| 1,727 \| 35 \| 1,692 \| 1,359 \| 368 \|
	\| with_spoon \| 1,582 \| 2 \| 1,580 \| 1,290 \| 292 \|
	\| with_knife_and_fork \| 1,165 \| 71 \| 1,094 \| 974 \| 191 \|
	\| with_fork \| 878 \| 3 \| 875 \| 779 \| 99 \|
	\| Total \| 95,190 \| 76,905 \| 18,285 \| 76,025 \| 19,165 \|

	### `eating_recognition`

	\| Split \| Faces \| Eating \| Not eating \| Videos \|
	\|---\|---\|---\|---\|---\|
	\| train \| 5,033 \| 3,108 \| 1,925 \| 537 \|
	\| test \| 1,247 \| 770 \| 477 \| 353 \|

	The split is stratified 4:1 within each (category, label) group, as in the paper. It was made per image, not per video, so 332 videos have frames in both train and test. Keep this in mind when you interpret test accuracy.

	---

	## Statistics (`hand_object_detection`, both splits combined)

	- Hands: 190,333 (left 85,797 / right 104,536). In contact with an object: 165,419. No contact: 24,914.
	- Faces: 151,620 (eating 69,251 / not eating 82,369). Every image has 1–5 faces. A few images contain faces but no annotated hands.
	- Faces per image: 1 face 56,153 images · 2 faces 27,518 · 3 faces 7,142 · 4 faces 2,880 · 5 faces 1,497.

	---

	## Baseline results

	Results reported in the paper on the paper split (test set), with mAP at IoU > 0.5 (see the paper §5.1 for the hand-object matching rule).

	SOV-STG-H2E-S (multi-task, single model):

	\| Left hand: no contact \| Left hand: portable object \| Right hand: no contact \| Right hand: portable object \| Hand-object mAP \| Face: not eating \| Face: eating \| Face mAP \|
	\|---\|---\|---\|---\|---\|---\|---\|---\|
	\| 61.91 \| 87.79 \| 47.98 \| 88.56 \| 71.56 \| 57.43 \| 73.89 \| 65.66 \|

	Eating action recognition (`eating_recognition`), ResNet-50 (ImageNet-1K pre-trained, fine-tuned): 86.4% test accuracy.

	The trained models are not released.

	---

	## How the dataset was built

	1. Video collection. Eating and drinking videos were collected for 12 scenarios (e.g. eating hamburger, drinking beer, eating with a spoon). The videos themselves are not distributed.
	2. Frame extraction. A PPDM hand-object interaction detector trained on 100DOH and a RetinaFace (ResNet-50) face detector were run at 1 frame per second. Frames where a hand-held object overlapped the mouth landmarks were kept: 99,903 frames.
	3. Eating labels for faces. 6,280 face crops were labelled manually (eating / not eating). This is the `eating_recognition` config. A ResNet-50 classifier trained on them then labelled all faces automatically.
	4. Hand-object annotation. An SOV-STG-Hand model (trained on 100DOH, re-categorised into no contact / portable object) produced hand, side, contact and object boxes. Object categories were added and all annotations were then checked and corrected manually with the VIA annotation tool. Frames that could not be annotated reliably were marked invalid.
	5. Filtering. We removed images without faces, images with more than 5 faces, and images whose largest face is smaller than 400 px. Faces smaller than 300 px were removed. Together with the invalid frames, this reduced the 97,484 verified frames to 95,190 images.

	Labelling rules for eating faces: a face is eating if the person is performing the act of eating (mouth open with food or utensil entering it, or the face clearly shows eating while an object covers the mouth). An object in front of a closed mouth counts as not eating. Images that cannot be judged were not labelled.

	---

	## Limitations and biases

	- Partly automatic labels. Face boxes come from RetinaFace. Eating labels on detection faces come from a classifier, and hand-object boxes were pre-annotated by a model before manual checking. Some errors remain (see the paper, Fig. 6c).
	- Domain. The videos are mostly eating vlogs filmed for an audience: frontal faces, often a single person, good lighting. The foods are limited to the 12 scenario categories, and the people and regions shown are not representative of the world population.
	- Boxes outside the image. Some boxes extend beyond the image border (for example, negative coordinates for a face cut off at the top): 517 face boxes and 488 hand/object boxes in `hand_object_detection`, and 1,156 of the 6,280 face boxes in `eating_recognition` (these come directly from the face detector). They are kept exactly as used in the paper; clip them to `[0, width] × [0, height]` if your code requires it. `face_crop` is padded with black where the box leaves the image.
	- Category imbalance. `unknown` (id 12) has only 19 instances and `can` 875. The `with_*` categories are much smaller than the food categories.
	- Paper split coverage. See [Splits](#splits): the paper's test set covers only 5 of the 12 categories in meaningful numbers.

	## Ethical considerations

	The images show real, identifiable people taken from publicly available videos. The dataset is intended only for research on eating behaviour and dietary assessment. It must not be used for face recognition, identification, tracking or profiling of individuals (see the license).

	Removal requests. If you appear in the dataset or own one of the source videos and want content removed, contact `chen-j@mm.inf.uec.ac.jp` with the `file_name` or `video_id`. We will remove it from this repository.

	---

	## License

	The annotations, metadata and scripts are released under the [HowToEat Research-Only License](LICENSE.md). In short:

	- ✅ Non-commercial research and education
	- ❌ Commercial use of any kind, including training commercial models
	- ❌ Redistribution or re-hosting (a few example images in publications are fine)
	- ❌ Face recognition, identification or surveillance
	- 📌 Citation of the paper is required

	The images are frames from publicly available online videos. Their copyright belongs to the original video owners, and the authors do not grant any rights to them. They are made available for research use only, to the extent permitted by applicable law.

	---

	## Citation

	```bibtex
	@inproceedings{wang2023howtoeat,
	title = {{HowToEat}: Exploring Human Object Interaction and Eating Action in Eating Scenarios},
	author = {Wang, Yingcheng and Chen, Junwen and Yanai, Keiji},
	booktitle = {Proceedings of the 8th International Workshop on Multimedia Assisted Dietary Management},
	series = {MADiMa '23},
	pages = {71--78},
	year = {2023},
	publisher = {Association for Computing Machinery},
	address = {New York, NY, USA},
	location = {Ottawa, ON, Canada},
	doi = {10.1145/3607828.3617790},
	url = {https://doi.org/10.1145/3607828.3617790}
	}
	```

	## Acknowledgments

	This work was supported by JSPS KAKENHI Grant Numbers 21H05812, 22H00540, 22H00548, and 22K19808.