CALI is a software library for the development of Calligraphic Interfaces (intelligent interfaces based on sketches and gesture interaction) centered mainly on a simple Shape Recognizer.
This recognizer is a fast, simple and compact approach to identify Scribbles (multi-stroke geometric shapes) drawn with a stylus on a digitizing tablet. Our method combines temporal adjacency, Fuzzy Logic and geometric features to classify scribbles.
This algorithm recognizes elementary geometric shapes, such as Triangles, Rectangles, Diamonds, Circles, Ellipses, Lines and Arrows, and some gesture commands, such as, Delete, Cross, WavyLine, Move, Copy and Tap. Shapes are recognized independently of changes in rotation, size or number of individual strokes.
The recognizer has a recognition rate of 97% and a fast response characteristic making it very usable in interactive applications.
The figure below shows the different shapes and gestures identified by the recognizer.
Besides the ones enumerated in the figure, it also recognizes the Tap gesture.
The source code and documentation is released under the terms of the GNU General Public License.
Please send to Manuel J. da Fonseca. Thank you!