The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 10, 1996
Filed:
Sep. 30, 1993
Arnaud P Gourdol, Cupertino, CA (US);
Apple Computer, Inc., Cupertino, CA (US);
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. A different method of implementing fuzzy recognition includes smoothing the stroke, normalizing the smoothed stroke, determining whether the normalized stroke matches one of a plurality of gesture prototypes, and, if so, selecting the gesture associated with the best matched gesture prototype as the appropriate interpretation of the stroke. The step of normalizing the stroke preferably includes storing normalized coordinates in at least one 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, such as bracket gestures and pigtail gestures, well as gestures input by a user that represent one of said standard gestures. An alternative embodiment of both methods includes a step of determining whether the stroke is part of a multiple stroke gesture, and, if so, adding the stroke to stroke portions previously input by the user.