Abstract: An improved recognition data structure is described that is particularly well suited for use in a computer system having recognition abilities. The data structure includes a multi-representational data list section arranged to store a multiplicity of datum. Each datum includes a datum reference number that uniquely identifies that datum and is arranged to contain a plurality of representation zones. Each representation zone is arranged to hold data indicative of a particular representation of the data stored in the datum. The data structure also includes a trellis based recognition results section arranged to accommodate trellis based recognition results at a plurality of different trellis levels.

Abstract: A method and apparatus for recognizing a gesture input on a display screen of a computer system. A stroke is input by a user on the screen, and the stroke is smoothed by reducing the number of points that define the stroke. The number of points are reduced by calculating a weighted position for a new point between two adjacent points that are within a threshold distance, and replacing a plurality of points that are separated by less than the threshold distance with the new point. The stroke is also normalized by dividing coordinates of the points by a scaling factor and storing selected points of the stroke in a prototype buffer. The normalized stroke is matched to one or more of a plurality of gesture prototypes by utilizing a correlation score that is calculated for each prototype. The gesture prototypes preferably include standard gestures having standardized shapes as well as gestures input by a user, and include bracket and pigtail gestures.

Abstract: A method and apparatus for recognizing an ellipse-type gesture input on a display screen of a computer system. A stroke is input by a user onto a computer screen, and the stroke is smoothed by reducing the number of points that represent the stroke. It is determined whether the smoothed stroke includes at least a predetermined minimum number of points, and, if so, angles between adjacent segments of the smoothed stroke and derivatives of the angles are calculated. It is determined if the stroke substantially represents an ellipse by checking if the stroke curves in one direction or more than one direction utilizing the angles and the derivatives of the angles. In addition, the stroke represents an ellipse if the end points are within a predetermined distance of each other, and if a sum of the derivatives of the angles is within a predetermined range of values. The method preferably includes selecting an object on the screen if the object is substantially overlapped by the smoothed stroke.

Abstract: A method and apparatus for recognizing a gesture input on a display screen of a computer system. A method of recognizing an ellipse gesture comprises the steps of receiving a stroke input by a user onto a computer screen, smoothing the stroke by reducing the number of points that represent the stroke, determining whether the smoothed stroke includes at least a predetermined minimum number of points, and, if so, calculating angles between adjacent segments of the smoothed stroke and calculating derivatives of the angles. It is determined if the stroke substantially represents an ellipse by utilizing the angles and the derivatives of the angles. The method preferably includes selecting an ink object on the screen if the ink object is substantially overlapped by the smoothed stroke.