Swipe Text Input for Touchless Interfaces

Swipe typing has been designed for touchscreen devices and consists of sliding a finger or stylus through consecutive letters lifting only between words. Since the tracked path contains many redundant letters the accurate recognition of intended word requires a good input path analyser and a word search engine. There are many proprietary solutions of swipe typing available on the market; however, all of them focus on touchscreen devices. On the other hand, there is a growing number of non-contact interfaces operated with gestures. These interfaces limit their operation to pointer manipulation in graphical user interface. The problem of typing in most cases is omitted. Of course touchless interfaces are not designed for text entry purposes but at least some decent possibility of text entry is necessary. In this paper the word recognition algorithm from the tracked path created by the hand movement in front of the wall screen projector is proposed. It is compared with other solutions based on individual key selection in touchless environment.