Method and apparatus for on-top writing

摘要

A handwriting recognition apparatus facilitates user entry of strokes one on top of another. The apparatus, which includes a processor and a display integrated with a touch sensitive screen, receives a series of strokes via the screen. Each stroke is defined by contact, trace, and lift occurrences. Each stroke appears on the display until occurrence of a prescribed event, and then disappears. The apparatus accumulates strokes into a buffer and interprets all accumulated strokes collectively against a character database and optionally a linguistic database, to identify multiple candidate strings that could be represented by the accumulated strokes. The apparatus displays candidate strings for user selection after all strokes have faded, or after receiving a user submitted delimiter, or after a given delay has elapsed following user entry of the latest stroke. Alternatively, candidate strings are displayed after each stroke without waiting for timeout or explicit delimiter.

主权项

1. A handwriting recognition apparatus, comprising:
an electrically driven display integrated with a touch sensitive screen; machine-readable storage containing any of: a character database representing predefined character shape data, the character database and a linguistic database representing predefined character strings; and a processor coupled to the display and storage, the processor programmed to perform operations comprising:
receiving a series of multiple strokes via the touch sensitive screen, each stroke defined by a contact, trace, and lift of a stylus or finger or other member;presenting each stroke on the display until occurrence of a prescribed event after which the displayed stroke disappears;accumulating strokes into a buffer and interpreting all accumulated strokes collectively against one of the following to identify multiple candidate strings that could potentially be represented by the accumulated strokes: the character database alone, the character database and the linguistic database;where the operation of interpreting all accumulated strokes comprises:
combining input strokes in different ways to produce alternative configurations;for each alternative configuration, comparing stroke input with the character database to produce multiple character q candidates and a character distance for each candidate, wherein q is a positive integer greater than or equal to two; andconcatenating said character candidates in different combinations to produce complete candidate strings each comprising a potential representation of user-intended strokes from start to end; andproducing a ranked list of the complete candidate strings according to a score of each candidate string, where scores are produced by weighing the distances of the concatenated characters and string likeliness according to said linguistic database such that strings that are more likely to represent the accumulated strokes are ranked higher and strings that are less likely to represent the accumulated strokes or absent from the linguistic database are ranked lower;andoperating the display to present candidate strings for user selection, the candidate strings being displayed upon one of the following basis: (1) only after all strokes have disappeared, (2) only after receiving a predefined user submitted delimiter, (3) only after a predetermined delay has elapsed following user entry of a most recent stroke.