Incremental recognition in gesture-based and syntax-directed diagram editors

Diagram editing is an attractive application of gestural interfaces and pen-based computers which promise a new input paradigm where users communicate with computers in diagram languages by using gestures. A key problem in building gesture-based diagram editors is the recognition of handsketched diagrams. Existing approaches concentrate either on gesture recognition or on parsing visual languages, there has been a lack of integrated recognition concepts. This paper presents novel concepts and techniques based on an incremental paradigm of gesture recognition and a cooperative communication between modules for pattern recognition and for diagram parsing. These concepts and techniques have been used successfully to build several experimental gesture-based and syntax-directed diagram editors.