User-directed sketch interpretation

Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2004.Includes bibliographical references (p. 91-92).I present a novel approach to creating structured diagrams (such as flow charts and object diagrams) by combining an off-line sketch recognition system with the user interface of a traditional structured graphics editor. The system, called UDSI (user-directed sketch interpretation), aims to provide drawing freedom by allowing the user to sketch entirely off-line using a pure pen-and-paper interface. The results of the drawing can then be presented to UDSI, which recognizes shapes and lines and text areas that the user can then polish as desired. The system can infer multiple interpretations for a given sketch, to aid during the user's polishing stage. The UDSI program offers three novel features. First, it implements a greedy algorithm for determing alternative interpretations of the user's original pen drawing. Second, it introduces a user interface for selecting from these multiple candidate interpretations. Third, it implements a circle recognizer using a novel circle-detection algorithm and combines it with other hand-coded recognizers to provide a robust sketch recognition system.by Matthew J. Notowidigdo.M.Eng

Kinematic Templates: Guiding Cursor Movement in End-User Drawing Tools

This thesis presents kinematic templates, end-user drawing tools that influence the mouse cursor's movement within specific areas of a digital canvas. Two types of kinematic templates influence the cursor's movement: passive and active templates. Passive templates modify existing movement received from a pointing device to change the cursor's speed or direction of one's stroke. Active templates add movement to the cursor without movement from the pointing device. Since templates are provided as user-specified regions, these regions can be associated with areas of detail and they can be overlapped as a means of function composition. [¶] A kinematic template can be configured to improve upon one's freehand output without producing perfect output. Since templates do not necessarily prescribe geometric output, they constitute a visual composition aid that lies between unaided freehand drawing and drawing aids such as snapping constraints and perfect geometric primitives. [¶] Since kinematic templates can improve upon the consistency of one's strokes, it is beneficial for drawing visual styles such as hatching (an artistic effect that adds depth to a drawing with uniform strokes drawn in close proximity) and repetitive patterns. Since kinematic templates do not prescribe a type of output, one can "fight against" a template's preferred path of movement and discover unexpected, serendipitous outcomes