This repository is a public implementation of the paper: "DAN: a Segmentation-free Document Attention Network for Handwritten Document Recognition".

The model uses a character-level attention to handle slanted lines:

The paper is available at https://arxiv.org/abs/2203.12273.

To discover my other works, here is my academic page.

Click to see the demo:

This work focus on handwritten text and layout recognition through the use of an end-to-end segmentation-free attention-based network. We evaluate the DAN on two public datasets: RIMES and READ 2016 at single-page and double-page levels.

We obtained the following results:

Pretrained model weights are available here and here.

Table of contents:

1. Getting Started
2. Datasets
3. Training And Evaluation

We used Python 3.9.1, Pytorch 1.8.2 and CUDA 10.2 for the scripts.

Clone the repository:

git clone https://github.com/FactoDeepLearning/DAN.git

Install the dependencies:

pip install -r requirements.txt

An example script file is available at OCR/document_OCR/dan/predict_examples to recognize images directly from paths using trained weights

This section is dedicated to the datasets used in the paper: download and formatting instructions are provided for experiment replication purposes.

RIMES dataset at page level was distributed during the evaluation compaign of 2009.

READ 2016 dataset corresponds to the one used in the ICFHR 2016 competition on handwritten text recognition. It can be found here

Raw dataset files must be placed in Datasets/raw/{dataset_name}
where dataset name is "READ 2016" or "RIMES"

python3 Datasets/dataset_formatters/read2016_formatter.py
python3 Datasets/dataset_formatters/rimes_formatter.py

python3 OCR/line_OCR/ctc/main_syn_line.py

There are two lines in this script to adapt to the used dataset:

model.generate_syn_line_dataset("READ_2016_syn_line")
dataset_name = "READ_2016"

python3 OCR/line_OCR/ctc/main_line_ctc.py

There are two lines in this script to adapt to the used dataset:

dataset_name = "READ_2016"
"output_folder": "FCN_read_line_syn"

Weights and evaluation results are stored in OCR/line_OCR/ctc/outputs

python3 OCR/document_OCR/dan/main_dan.py

The following lines must be adapted to the dataset used and pre-training folder names:

dataset_name = "READ_2016"
"transfer_learning": {
    # model_name: [state_dict_name, checkpoint_path, learnable, strict]
    "encoder": ["encoder", "../../line_OCR/ctc/outputs/FCN_read_2016_line_syn/checkpoints/best.pt", True, True],
    "decoder": ["decoder", "../../line_OCR/ctc/outputs/FCN_read_2016_line_syn/best.pt", True, False],
},

Weights and evaluation results are stored in OCR/document_OCR/dan/outputs

All hyperparameters are specified and editable in the training scripts (meaning are in comments).
Evaluation is performed just after training ending (training is stopped when the maximum elapsed time is reached or after a maximum number of epoch as specified in the training script).
The outputs files are split into two subfolders: "checkpoints" and "results".
"checkpoints" contains model weights for the last trained epoch and for the epoch giving the best valid CER.
"results" contains tensorboard log for loss and metrics as well as text file for used hyperparameters and results of evaluation.

@article{Coquenet2023b,
  author = {Coquenet, Denis and Chatelain, Clément and Paquet, Thierry},
  title = {DAN: a Segmentation-free Document Attention Network for Handwritten Document Recognition},
  doi={10.1109/TPAMI.2023.3235826}
  journal={IEEE Transactions on Pattern Analysis and Machine Intelligence},
  volume={45},
  number={7},
  pages={8227-8243},
  year = {2023},
}

This whole project is under Cecill-C license.