Bank OCR CAPTCHA Solver API

This project is a deep learning-based OCR solution designed to automatically solve CAPTCHA images from various Vietnamese banks including MB Bank, BIDV, Vietcombank, and Eximbank. It uses TensorFlow/Keras with CTC decoding and a Flask-based API for real-time CAPTCHA recognition.

Features

• Trained OCR models per bank (MB Bank, BIDV, Eximbank, Vietcombank)
• Flask REST API endpoints for CAPTCHA solving
• Supports base64-encoded PNG images
• Uses TensorFlow, Keras, and custom CTC loss layer
• Character-level prediction with bidirectional LSTM layers

Installation

1. Clone the repo:

   git clone https://github.com/your-repo/bank-captcha.git
   cd bank-captcha

2. Install dependencies:

   pip install -r requirements.txt

3. Run the server:

   python app.py

API Usage

POST to one of the following endpoints with JSON body:

{
  "base64": "your_image_data_base64"
}

• /api/captcha/mbbank
• /api/captcha/bidv
• /api/captcha/eximbank
• /api/captcha/vietcombank

Example Response

{
  "status": "success",
  "captcha": "smcm"
}

Use the provided training script to preprocess data, define and train the model, and export it using JSON and weight files. Models can be reloaded using LoadModel().

License

MIT License