PaddleOCR/StyleText

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Style Text

Contents

• 1. Introduction
• 2. Preparation
• 3. Quick Start
• 4. Applications
• 5. Code Structure

Introduction

The Style-Text data synthesis tool is a tool based on Baidu's self-developed text editing algorithm "Editing Text in the Wild" https://arxiv.org/abs/1908.03047.

Different from the commonly used GAN-based data synthesis tools, the main framework of Style-Text includes:

• (1) Text foreground style transfer module.
• (2) Background extraction module.
• (3) Fusion module.

After these three steps, you can quickly realize the image text style transfer. The following figure is some results of the data synthesis tool.

Preparation

1. Please refer the QUICK INSTALLATION to install PaddlePaddle. Python3 environment is strongly recommended.
2. Download the pretrained models and unzip:

cd StyleText
wget https://paddleocr.bj.bcebos.com/dygraph_v2.0/style_text/style_text_models.zip
unzip style_text_models.zip

If you save the model in another location, please modify the address of the model file in configs/config.yml, and you need to modify these three configurations at the same time:

bg_generator:
  pretrain: style_text_rec/bg_generator
...
text_generator:
  pretrain: style_text_models/text_generator
...
fusion_generator:
  pretrain: style_text_models/fusion_generator

Quick Start

Synthesis single image

1. You can run tools/synth_image and generate the demo image, which is saved in the current folder.

python3 -m tools.synth_image -c configs/config.yml --style_image examples/style_images/2.jpg --text_corpus PaddleOCR --language en

• Note 1: The language options is correspond to the corpus. Currently, the tool only supports English, Simplified Chinese and Korean.
• Note 2: Synth-Text is mainly used to generate images for OCR recognition models. So the height of style images should be around 32 pixels. Images in other sizes may behave poorly.

For example, enter the following image and corpus PaddleOCR.

The result fake_fusion.jpg will be generated.

What's more, the medium result fake_bg.jpg will also be saved, which is the background output.

fake_text.jpg * fake_text.jpg is the generated image with the same font style as Style Input.

Batch synthesis

In actual application scenarios, it is often necessary to synthesize pictures in batches and add them to the training set. StyleText can use a batch of style pictures and corpus to synthesize data in batches. The synthesis process is as follows:

1. The referenced dataset can be specifed in configs/dataset_config.yml:

   • Global：
     • output_dir:：Output synthesis data path.
   • StyleSampler：
     • image_home：style images' folder.
     • label_file：Style images' file list. If label is provided, then it is the label file path.
     • with_label：Whether the label_file is label file list.
   • CorpusGenerator：
     • method：Method of CorpusGenerator，supports FileCorpus and EnNumCorpus. If EnNumCorpus is used，No other configuration is needed，otherwise you need to set corpus_file and language.
     • language：Language of the corpus.
     • corpus_file: Filepath of the corpus. Corpus file should be a text file which will be split by line-endings（'\n'）. Corpus generator samples one line each time.

Example of corpus file:

PaddleOCR
飞桨文字识别
StyleText
风格文本图像数据合成

We provide a general dataset containing Chinese, English and Korean (50,000 images in all) for your trial (download link), some examples are given below :

2. You can run the following command to start synthesis task:

   python -m tools.synth_dataset.py -c configs/dataset_config.yml
   

We also provide example corpus and images in examples folder.

If you run the code above directly, you will get example output data in output_data folder. You will get synthesis images and labels as below:

There will be some cache under the `label` folder. If the program exit unexpectedly, you can find cached labels there. When the program finish normally, you will find all the labels in `label.txt` which give the final results.

Applications

We take two scenes as examples, which are metal surface English number recognition and general Korean recognition, to illustrate practical cases of using StyleText to synthesize data to improve text recognition. The following figure shows some examples of real scene images and composite images:

After adding the above synthetic data for training, the accuracy of the recognition model is improved, which is shown in the following table:

Scenario	Characters	Raw Data	Test Data	Only Use Raw Data Recognition Accuracy	New Synthetic Data	Simultaneous Use of Synthetic Data Recognition Accuracy	Index Improvement
Metal surface	English and numbers	2203	650	0.5938	20000	0.7546	16%
Random background	Korean	5631	1230	0.3012	100000	0.5057	20%

Code Structure

StyleText
|-- arch                        // Network module files.
|   |-- base_module.py
|   |-- decoder.py
|   |-- encoder.py
|   |-- spectral_norm.py
|   `-- style_text_rec.py
|-- configs                     // Config files.
|   |-- config.yml
|   `-- dataset_config.yml
|-- engine                      // Synthesis engines.
|   |-- corpus_generators.py    // Sample corpus from file or generate random corpus.
|   |-- predictors.py           // Predict using network.
|   |-- style_samplers.py       // Sample style images.
|   |-- synthesisers.py         // Manage other engines to synthesis images.
|   |-- text_drawers.py         // Generate standard input text images.
|   `-- writers.py              // Write synthesis images and labels into files.
|-- examples                    // Example files.
|   |-- corpus
|   |   `-- example.txt
|   |-- image_list.txt
|   `-- style_images
|       |-- 1.jpg
|       `-- 2.jpg
|-- fonts                       // Font files.
|   |-- ch_standard.ttf
|   |-- en_standard.ttf
|   `-- ko_standard.ttf
|-- tools                       // Program entrance.
|   |-- __init__.py
|   |-- synth_dataset.py        // Synthesis dataset.
|   `-- synth_image.py          // Synthesis image.
`-- utils                       // Module of basic functions.
    |-- config.py
    |-- load_params.py
    |-- logging.py
    |-- math_functions.py
    `-- sys_funcs.py