Recognition and beautification of multi-stroke symbols in digital ink

Sketch-based user interfaces (UIs) provide a more direct and convenient way for interacting with computers, especially for performing graphical tasks. Most computer programs provide a mouse-and-palette-based UI for editing shapes, which can be cumbersome to use. In order to draw a shape, a user must first select the desired shape from a menu or from a hierarchy of menus, and then make a series of adjustments to the shape (i.e. rotation, scaling, horizontal/vertical flip, etc.). A more convenient approach to this task is to allow the user to sketch the desired shape directly and then replace it with a 'beautified' symbol with the correct transformation, all in one step. In this paper, we present a complete system for recognizing and beautifying sketched symbols. We have implemented this system as an interface to the Microsoft PowerPoint application to enable a user to sketch symbols directly onto a presentation slide.