Time-segmentation- and Position-free Recognition from Video of Air-drawn Gestures and Characters

We report on the recognition from a video of isolated alphabetic characters and connected cursive characters, such as Hiragana or Kanji characters, drawn in the air. This topic involves a number of difficult problems in computer vision such as the segmentation and recognition of complex motion from a video. We utilize an algorithm called time-space continuous dynamic programming (TSCDP) that can realize both time and location-free (spotting) recognition. Spotting means that prior segmentation of the input video is not required. Each of the reference (model) characters used is represented by a single stroke composed of pixels. We conducted two experiments involving the recognition of 26 isolated alphabetic characters and 23 Japanese Hiragana and Kanji air-drawn characters. Moreover we conducted gesture recognition based on TSCDP and showed that TSCDP was free from many restrictions required for conventional methods.