Research on a Finger-Joint Tracking-Based Character Recognition System

The increasing need for seamless human-computer interaction (HCI) has driven researchers to explore innovative input systems. My recent research, titled “Implementation of a Character Recognition System Based on Finger-Joint Tracking Using a Depth Camera,” tackles one of the emerging challenges in HCI: recognizing characters through finger-joint movements. This study presents a sophisticated method that identifies digits, alphabets, and special characters through the tracking of finger-joint motions, offering a robust solution for both single-hand and double-hand recognition tasks.

Motivation

Traditional input systems like keyboards and touch screens have their limitations, especially in environments where hands-free or mid-air input is preferred. The idea of gesture-based character recognition can fill this gap, providing users with the flexibility to write in mid-air using simple hand gestures. The motivation behind this research is to build a versatile, user-friendly system that can operate in various lighting conditions, including complete darkness. During situations such as the COVID-19 pandemic, where touch-based systems present health risks, a gesture-based system can prove invaluable.

Moreover, existing systems either require cumbersome wearable devices or offer limited gesture recognition, often confined to digits or a small set of characters. By tracking finger joints in three dimensions, this research aims to overcome those limitations and create a fully functional system that can handle all characters on a standard keyboard.

Results

The system was able to achieve an impressive accuracy rate—91.95% for single-hand recognition and 91.85% for double-hand recognition. It processed each character in less than 60 milliseconds, proving its potential for real-time applications. This research stands out for its ability to operate in both light and dark environments, without compromising on accuracy or speed. The system also supports 124 characters, including digits, alphabets, symbols, and special keys, making it versatile enough to mimic a full keyboard input method.

Technology Used

At the core of this system is a 3-D depth camera, specifically the Intel RealSense SR300, which captures both RGB and depth information in real-time. The system uses a combination of Euclidean distance thresholding and geometric slope techniques to accurately identify finger joints. Each hand consists of 22 key joints, and by analyzing the distances between them, the system can determine which character is being written.

This joint-tracking-based method is far more sophisticated than traditional gesture recognition techniques, as it focuses on finger joints rather than whole-hand gestures. This approach significantly reduces the computational complexity while increasing the number of possible gestures, making the system both scalable and efficient.

Key Takeaways

  • Versatility: The system supports a wide range of characters, allowing it to act as a virtual keyboard with 124 characters. It can be applied in various industries requiring hands-free input systems, including healthcare, virtual reality, and accessibility tools.
  • Lighting Conditions: Unlike many conventional recognition systems that rely heavily on lighting, this system performs equally well in both light and dark environments.
  • Real-Time Application: With a recognition time of less than 60 milliseconds per character, the system is optimized for real-time use, ensuring that users can type or input data quickly and efficiently.
  • Gesture Simplicity: The user study revealed that even novices found the system intuitive, with minimal effort required to learn the gesture combinations.

This research marks a significant step forward in the development of efficient, flexible, and reliable gesture-based input systems. By using innovative technology and thoughtful system design, it promises to be a practical solution for enhancing human-computer interaction.

Reference

Please find this research here – https://doi.org/10.1109/THMS.2021.3066854

Cite this research paper –

@ARTICLE{9404361,
  author={Alam, Md. Shahinur and Kwon, Ki-Chul and Kim, Nam},
  journal={IEEE Transactions on Human-Machine Systems}, 
  title={Implementation of a Character Recognition System Based on Finger-Joint Tracking Using a Depth Camera}, 
  year={2021},
  volume={51},
  number={3},
  pages={229-241},
  keywords={Writing;Gesture recognition;Cameras;Character recognition;Tracking;Keyboards;Thumb;Character recognition;finger-joint tracking;gesture-based writing;human-computer interaction (HCI)},
  doi={10.1109/THMS.2021.3066854}}