Before revision:  This paper, thus, proposes a touch-less typing interface that makes use of an on-screen QWERTY keyboard and a front-facing smartphone cameramounted on a stand. The keys of the keyboard are grouped into nine color-coded clusters.
After revision:  This paper, thus, proposes a touch-less typing interface that makes use of an on-screen QWERTY keyboard and a smartphone camera. The keyboard was divided into nine color-coded clusters.