Datasets:
Languages:
English
Size:
1M<n<10M
Tags:
handwriting-recognition
htr
self-supervised-learning
historical-documents
writer-identification
License:
Update README.md
Browse files
README.md
CHANGED
|
@@ -1,7 +1,317 @@
|
|
| 1 |
---
|
| 2 |
license: apache-2.0
|
|
|
|
|
|
|
|
|
|
| 3 |
language:
|
| 4 |
- en
|
| 5 |
size_categories:
|
| 6 |
-
-
|
| 7 |
-
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| 1 |
---
|
| 2 |
license: apache-2.0
|
| 3 |
+
task_categories:
|
| 4 |
+
- image-to-text
|
| 5 |
+
- image-classification
|
| 6 |
language:
|
| 7 |
- en
|
| 8 |
size_categories:
|
| 9 |
+
- 1M<n<10M
|
| 10 |
+
tags:
|
| 11 |
+
- handwriting-recognition
|
| 12 |
+
- htr
|
| 13 |
+
- self-supervised-learning
|
| 14 |
+
- historical-documents
|
| 15 |
+
- writer-identification
|
| 16 |
+
pretty_name: SSL-HWD
|
| 17 |
+
---
|
| 18 |
+
|
| 19 |
+
# SSL-HWD (A Large Scale Handwritten Image Dataset)
|
| 20 |
+
|
| 21 |
+
## Dataset Description
|
| 22 |
+
|
| 23 |
+
### Dataset Summary
|
| 24 |
+
|
| 25 |
+
**SSL-HWD** is a large-scale handwritten text dataset introduced in the paper ["Learning Beyond Labels: Self-Supervised Handwritten Text Recognition"](https://logo-ssl.github.io/) (WACV 2026). The dataset comprises **10 million word-level handwritten images** from **852 writers** across diverse domains including Physics, Computer Science, Biology, Mathematics, and more.
|
| 26 |
+
|
| 27 |
+
The dataset is specifically designed to support **self-supervised learning** approaches for Handwritten Text Recognition (HTR), addressing the critical challenge of reducing dependence on large volumes of labeled data.
|
| 28 |
+
|
| 29 |
+
### Dataset Composition
|
| 30 |
+
|
| 31 |
+
- **Total Words**: 10 million word-level images
|
| 32 |
+
- **Writers**: 852 unique contributors
|
| 33 |
+
- **Pages**: 81,280 scanned document pages
|
| 34 |
+
- **Domains**: 20+ domains including sciences, literature, and mathematics
|
| 35 |
+
- **Labeled Subset**: 2.08M words (20.8%) with ground truth transcriptions
|
| 36 |
+
- **Unlabeled Subset**: 7.92M words (79.2%) for self-supervised pretraining
|
| 37 |
+
- **Unique Vocabulary**: 107,813 unique words
|
| 38 |
+
|
| 39 |
+
### Key Features
|
| 40 |
+
|
| 41 |
+
**Diversity and Complexity**: The dataset includes challenging real-world scenarios:
|
| 42 |
+
- Texts with different font colors (varying ink and pen usage)
|
| 43 |
+
- Texts with difficult backgrounds (lines, noise interference)
|
| 44 |
+
- Texts with distorted characters (irregular strokes, structural inconsistencies)
|
| 45 |
+
- Texts with blurring effects (motion or focus issues)
|
| 46 |
+
- Texts with highlighted backgrounds (color markings obscuring content)
|
| 47 |
+
|
| 48 |
+
**Quality Assurance**:
|
| 49 |
+
- All samples automatically annotated using Amazon Textract with confidence ≥99%
|
| 50 |
+
- Labeled subset manually verified by language experts
|
| 51 |
+
- High-quality word segmentation with precise bounding boxes
|
| 52 |
+
|
| 53 |
+
### Comparison with Existing Datasets
|
| 54 |
+
|
| 55 |
+
| Dataset | Pages | Writers | Words | Unique Words |
|
| 56 |
+
|---------|-------|---------|-------|--------------|
|
| 57 |
+
| IAM | 1.5K | 657 | 115K | 10.5K |
|
| 58 |
+
| GNHK | 687 | - | 39K | 12.3K |
|
| 59 |
+
| IIIT-HW-English-Word | 20.8K | 1,215 | 757K | 174K |
|
| 60 |
+
| **SSL-HWD (Ours)** | **81.2K** | **852** | **10M** | **107K** |
|
| 61 |
+
|
| 62 |
+
### Vocabulary Distribution
|
| 63 |
+
|
| 64 |
+
| Category | SSL-HWD |
|
| 65 |
+
|----------|---------|
|
| 66 |
+
| Alphabetic Words | 61,088 |
|
| 67 |
+
| Numeric Words | 4,981 |
|
| 68 |
+
| Stop-words | 457 |
|
| 69 |
+
| Other Words | 41,287 |
|
| 70 |
+
| **Total Unique** | **107,813** |
|
| 71 |
+
|
| 72 |
+
## Dataset Structure
|
| 73 |
+
|
| 74 |
+
### Data Organization
|
| 75 |
+
|
| 76 |
+
```
|
| 77 |
+
SSL-HWD/
|
| 78 |
+
├── labeled/ # 2.08M labeled samples
|
| 79 |
+
│ ├── writer1/
|
| 80 |
+
│ │ ├── writer1.csv # Ground truth transcriptions
|
| 81 |
+
│ │ ├── writer1_1.png
|
| 82 |
+
│ │ ├── writer1_2.png
|
| 83 |
+
│ │ └── ...
|
| 84 |
+
│ ├── writer2/
|
| 85 |
+
│ └── ...
|
| 86 |
+
└── unlabeled/ # 7.92M unlabeled samples
|
| 87 |
+
├── writer1/
|
| 88 |
+
│ ├── writer1_1.png
|
| 89 |
+
│ ├── writer1_2.png
|
| 90 |
+
│ └── ...
|
| 91 |
+
└── ...
|
| 92 |
+
```
|
| 93 |
+
|
| 94 |
+
### Data Fields
|
| 95 |
+
|
| 96 |
+
**CSV Format (for labeled data)**:
|
| 97 |
+
- `image_filename` (string): Name of the word image file
|
| 98 |
+
- `transcription` (string): Ground truth text transcription
|
| 99 |
+
|
| 100 |
+
**Example**:
|
| 101 |
+
```csv
|
| 102 |
+
image_filename,transcription
|
| 103 |
+
writer1_1.png,handwritten
|
| 104 |
+
writer1_2.png,recognition
|
| 105 |
+
writer1_3.png,dataset
|
| 106 |
+
```
|
| 107 |
+
|
| 108 |
+
### Data Splits
|
| 109 |
+
|
| 110 |
+
The labeled subset (2.08M samples) is divided as follows:
|
| 111 |
+
- **Training**: 60% (1.25M samples)
|
| 112 |
+
- **Testing**: 40% (0.83M samples)
|
| 113 |
+
|
| 114 |
+
The unlabeled subset (7.92M samples) is used for self-supervised pretraining.
|
| 115 |
+
|
| 116 |
+
## Supported Tasks
|
| 117 |
+
|
| 118 |
+
### 1. Handwriting Text Recognition (HTR)
|
| 119 |
+
Train models to recognize handwritten text from word images.
|
| 120 |
+
|
| 121 |
+
### 2. Self-Supervised Learning
|
| 122 |
+
Use the large unlabeled subset for pretraining with methods like contrastive learning.
|
| 123 |
+
|
| 124 |
+
### 3. Writer Identification
|
| 125 |
+
Identify writers based on handwriting characteristics (852 unique writers).
|
| 126 |
+
|
| 127 |
+
### 4. Domain Adaptation
|
| 128 |
+
Transfer learning across different handwriting styles and domains.
|
| 129 |
+
|
| 130 |
+
### 5. Semi-Supervised Learning
|
| 131 |
+
Combine small labeled and large unlabeled subsets for improved performance.
|
| 132 |
+
|
| 133 |
+
## Usage
|
| 134 |
+
|
| 135 |
+
### Loading the Dataset
|
| 136 |
+
|
| 137 |
+
```python
|
| 138 |
+
from datasets import load_dataset
|
| 139 |
+
|
| 140 |
+
# Load the full dataset
|
| 141 |
+
dataset = load_dataset("your-username/ssl-hwd")
|
| 142 |
+
|
| 143 |
+
# Access labeled data
|
| 144 |
+
labeled = dataset['labeled']
|
| 145 |
+
|
| 146 |
+
# Access unlabeled data for self-supervised learning
|
| 147 |
+
unlabeled = dataset['unlabeled']
|
| 148 |
+
```
|
| 149 |
+
|
| 150 |
+
### Basic Example
|
| 151 |
+
|
| 152 |
+
```python
|
| 153 |
+
from PIL import Image
|
| 154 |
+
import pandas as pd
|
| 155 |
+
from pathlib import Path
|
| 156 |
+
|
| 157 |
+
# Load a writer's data
|
| 158 |
+
writer_folder = Path("labeled/writer1")
|
| 159 |
+
df = pd.read_csv(writer_folder / "writer1.csv")
|
| 160 |
+
|
| 161 |
+
# Load first image and transcription
|
| 162 |
+
img_name = df.iloc[0]['image_filename']
|
| 163 |
+
transcription = df.iloc[0]['transcription']
|
| 164 |
+
|
| 165 |
+
image = Image.open(writer_folder / img_name)
|
| 166 |
+
print(f"Transcription: {transcription}")
|
| 167 |
+
```
|
| 168 |
+
|
| 169 |
+
### PyTorch DataLoader
|
| 170 |
+
|
| 171 |
+
```python
|
| 172 |
+
import torch
|
| 173 |
+
from torch.utils.data import Dataset, DataLoader
|
| 174 |
+
from PIL import Image
|
| 175 |
+
import pandas as pd
|
| 176 |
+
|
| 177 |
+
class SSLHWDDataset(Dataset):
|
| 178 |
+
def __init__(self, writer_folder, transform=None):
|
| 179 |
+
self.folder = Path(writer_folder)
|
| 180 |
+
csv_file = list(self.folder.glob("*.csv"))[0]
|
| 181 |
+
self.data = pd.read_csv(csv_file)
|
| 182 |
+
self.transform = transform
|
| 183 |
+
|
| 184 |
+
def __len__(self):
|
| 185 |
+
return len(self.data)
|
| 186 |
+
|
| 187 |
+
def __getitem__(self, idx):
|
| 188 |
+
img_name = self.data.iloc[idx]['image_filename']
|
| 189 |
+
transcription = self.data.iloc[idx]['transcription']
|
| 190 |
+
|
| 191 |
+
img_path = self.folder / img_name
|
| 192 |
+
image = Image.open(img_path).convert('RGB')
|
| 193 |
+
|
| 194 |
+
if self.transform:
|
| 195 |
+
image = self.transform(image)
|
| 196 |
+
|
| 197 |
+
return image, transcription
|
| 198 |
+
|
| 199 |
+
# Usage
|
| 200 |
+
dataset = SSLHWDDataset('labeled/writer1')
|
| 201 |
+
dataloader = DataLoader(dataset, batch_size=32, shuffle=True)
|
| 202 |
+
```
|
| 203 |
+
|
| 204 |
+
## Benchmark Results
|
| 205 |
+
|
| 206 |
+
### State-of-the-Art Performance (from LoGo-HTR paper)
|
| 207 |
+
|
| 208 |
+
**IAM Dataset**:
|
| 209 |
+
- With 80% labeled data: WER 11.93%, CER 2.31%
|
| 210 |
+
- With 100% labeled data: WER 10.27%, CER 2.01%
|
| 211 |
+
|
| 212 |
+
**GNHK Dataset**:
|
| 213 |
+
- With 80% labeled data: WER 19.69%, CER 9.05%
|
| 214 |
+
- With 100% labeled data: WER 12.07%, CER 7.20%
|
| 215 |
+
|
| 216 |
+
**RIMES Dataset**:
|
| 217 |
+
- With 80% labeled data: WER 6.15%, CER 1.89%
|
| 218 |
+
- With 100% labeled data: WER 5.50%, CER 1.78%
|
| 219 |
+
|
| 220 |
+
**LAM Dataset** (line-level):
|
| 221 |
+
- With 80% labeled data: WER 7.2%, CER 3.2%
|
| 222 |
+
- With 100% labeled data: WER 6.3%, CER 2.39%
|
| 223 |
+
|
| 224 |
+
### Cross-Dataset Generalization
|
| 225 |
+
|
| 226 |
+
The dataset demonstrates strong cross-dataset transfer capabilities:
|
| 227 |
+
- SSL-HWD → IAM: WER 13.2%, CER 2.9%
|
| 228 |
+
- SSL-HWD → GNHK: WER 10.1%, CER 6.8%
|
| 229 |
+
- SSL-HWD → RIMES: WER 11.2%, CER 3.5%
|
| 230 |
+
- SSL-HWD → LAM: WER 16.4%, CER 7.2%
|
| 231 |
+
|
| 232 |
+
## Dataset Creation
|
| 233 |
+
|
| 234 |
+
### Source Data
|
| 235 |
+
|
| 236 |
+
The dataset was curated from publicly available digitized manuscripts from web sources, selected for being fully or substantially handwritten. Documents span:
|
| 237 |
+
- Personal diaries
|
| 238 |
+
- Academic notes
|
| 239 |
+
- Historical correspondence
|
| 240 |
+
- Scientific manuscripts
|
| 241 |
+
- Mathematical writings
|
| 242 |
+
- Literature and more
|
| 243 |
+
|
| 244 |
+
### Data Quality
|
| 245 |
+
|
| 246 |
+
- **Diverse Sources**: 852 unique writers across 20+ domains
|
| 247 |
+
- **Real-world Challenges**: Includes blur, noise, distortions, and background interference
|
| 248 |
+
|
| 249 |
+
## Applications
|
| 250 |
+
|
| 251 |
+
### Self-Supervised Learning (Primary Use)
|
| 252 |
+
Use the 7.92M unlabeled samples for pretraining with methods like:
|
| 253 |
+
- Contrastive learning (SimCLR, MoCo)
|
| 254 |
+
- Masked image modeling
|
| 255 |
+
- Local-global objectives (as in LoGo-HTR)
|
| 256 |
+
|
| 257 |
+
### Semi-Supervised Learning
|
| 258 |
+
Combine labeled and unlabeled subsets for improved performance with limited annotations.
|
| 259 |
+
|
| 260 |
+
### Few-Shot Learning
|
| 261 |
+
Train models with minimal labeled data by leveraging pretrained representations.
|
| 262 |
+
|
| 263 |
+
### Transfer Learning
|
| 264 |
+
Pretrain on SSL-HWD and fine-tune on domain-specific datasets.
|
| 265 |
+
|
| 266 |
+
## Limitations and Considerations
|
| 267 |
+
|
| 268 |
+
### Known Limitations
|
| 269 |
+
|
| 270 |
+
- **Language**: Primarily English handwritten text
|
| 271 |
+
- **Geographic Bias**: Predominantly Western handwriting styles
|
| 272 |
+
- **Historical Period**: Concentrated in specific time periods
|
| 273 |
+
- **Domain Coverage**: While diverse, may not represent all handwriting variations
|
| 274 |
+
|
| 275 |
+
### Ethical Considerations
|
| 276 |
+
|
| 277 |
+
- Dataset contains historical documents and handwritten materials
|
| 278 |
+
- Personal information may be present in some samples
|
| 279 |
+
- Users should be aware of privacy considerations when using this data
|
| 280 |
+
|
| 281 |
+
## Citation
|
| 282 |
+
|
| 283 |
+
If you use the SSL-HWD dataset in your research, please cite:
|
| 284 |
+
|
| 285 |
+
```bibtex
|
| 286 |
+
@inproceedings{mitra2026learning,
|
| 287 |
+
title={Learning Beyond Labels: Self-Supervised Handwritten Text Recognition},
|
| 288 |
+
author={Mitra, Shree and Mondal, Ajoy and Jawahar, C. V.},
|
| 289 |
+
booktitle={Proceedings of the IEEE/CVF Winter Conference on Applications of Computer Vision (WACV)},
|
| 290 |
+
year={2026}
|
| 291 |
+
}
|
| 292 |
+
```
|
| 293 |
+
|
| 294 |
+
## Additional Resources
|
| 295 |
+
|
| 296 |
+
- **Project Website**: [https://logo-ssl.github.io/](https://logo-ssl.github.io/)
|
| 297 |
+
|
| 298 |
+
## License
|
| 299 |
+
|
| 300 |
+
This dataset is released under the **Apache License 2.0**.
|
| 301 |
+
|
| 302 |
+
## Acknowledgments
|
| 303 |
+
|
| 304 |
+
This work is supported by MeitY, Government of India, through the NLTM-Bhashini project.
|
| 305 |
+
|
| 306 |
+
## Contact
|
| 307 |
+
|
| 308 |
+
For questions or issues regarding the dataset:
|
| 309 |
+
- **Authors**: Shree Mitra, Ajoy Mondal, C.V. Jawahar
|
| 310 |
+
- **Institution**: IIIT Hyderabad
|
| 311 |
+
- **Email**: shree.mitra@research.iiit.ac.in
|
| 312 |
+
|
| 313 |
+
---
|
| 314 |
+
|
| 315 |
+
**Dataset Version**: 1.0
|
| 316 |
+
**Last Updated**: January 2026
|
| 317 |
+
**Status**: Active
|