A CNN Based Framework for Unistroke Numeral Recognition in Air-Writing
This work addresses air-writing recognition for human-computer interaction, but it is incremental as it applies existing CNN and transfer learning methods to a new domain with specific data.
The paper tackled the problem of recognizing unistroke numerals written in air using hand gestures, achieving recognition rates of 97.7% for English, 95.4% for Bengali, and 93.7% for Devanagari numerals in person-independent evaluations.
Air-writing refers to virtually writing linguistic characters through hand gestures in three-dimensional space with six degrees of freedom. This paper proposes a generic video camera-aided convolutional neural network (CNN) based air-writing framework. Gestures are performed using a marker of fixed color in front of a generic video camera, followed by color-based segmentation to identify the marker and track the trajectory of the marker tip. A pre-trained CNN is then used to classify the gesture. The recognition accuracy is further improved using transfer learning with the newly acquired data. The performance of the system varies significantly on the illumination condition due to color-based segmentation. In a less fluctuating illumination condition, the system is able to recognize isolated unistroke numerals of multiple languages. The proposed framework has achieved 97.7%, 95.4% and 93.7% recognition rates in person independent evaluations on English, Bengali and Devanagari numerals, respectively.