A Virtual Handwriting Tablet Based on Pen Shadow Cues

摘要

The handwriting tablet is an electronic product, which is a kind of human-computer interfaces acting as a computer input device comprising a set of a special pen and a tablet. The user holds the pen to draw contents within a region of the tablet as inputs, which imitates handwriting and is a replacement of mouse inputs. Some handwriting tablets not only imitate the handwriting and mouse functions, but also detect the pen tilts and pressures. The tilt and pressure information can be applied to some drawing software which can also render the thickness and depth of strokes. However, since the handwriting tablet is a piece of precise equipment, it has some drawbacks- fragile, not easy to carry, and the weight is often heavy. Therefore, in this paper, we propose a new concept based on the computer vision technology to simulate the handwriting tablet. We put a rectangular plane in the FOV of a video camera to emulate a tablet, and use a conventional pen to emulate the stylus. Many experiments have been made for evaluating the effectiveness of the proposed methods. The performance of such a virtual handwriting tablet is very satisfactory and encouraged.