In recent years, the smart phones and tablet PCs are already ubiquitous in our daily life. There is no denying that finger-based touch input becomes the major interaction modality for the smart phones users. Also, the finger paint is one of the most commonly used operations. In Android platform, the finger paint is mainly implemented by the motion event class. However, it is limited by two points as follows. (1) When user's gesture is in a slow motion mode, too many coordinate points are produced and received. It will lead to a heavy computing and users may spend long time...