Preprocessing of multi-line rotated electronic ink

• US 7,010,165 B2
• Filed: 05/10/2002
• Issued: 03/07/2006
• Est. Priority Date: 05/10/2002
• Status: Expired due to Fees

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Abdulkader, Ahmad, Hullender, Gregory
• Primary Examiner(s): Wu, Jingge
• Assistant Examiner(s): Tarcu, Robert
• Application Number:
  US10/144,233
• Publication Number:
  US 20030210817A1
• Time in Patent Office: 1,397 Days
• Field of Search: 382/296
• US Class Current: 382/186
• CPC Class Codes: G06V 30/10 Character recognition
• CPC Class Codes: G06V 30/1423 the instrument generating sequences of position coordinates corresponding to handwriting preprocessing or recognising digital ink G06V30/32
• CPC Class Codes: G06V 30/1478 of characters or characters lines

Abstract

An electronic ink object is preprocessed for improving handwriting recognition results. An electronic ink object, possibly having multiple lines of non-horizontal ink, is preprocessed by segmenting or separating the electronic ink object into one or more lines, computing a writing angle of each line, and rotating each line so that it is horizontal.

Claims

1. A method of preprocessing an electronic ink object comprising the steps of:

(a) segmenting the electronic ink object comprising at least one ink stroke into at least one line by performing the steps of;

(i) identifying a plurality of features for each ink stroke of the electronic ink object; and

(ii) classifying each ink stroke as part of a new line, a current line, or a previous line;

(b) estimating a writing angle of each line;

(c) rotating each line to make horizontal a centerline of the line; and

wherein if the ink stroke is part of the current line, the step of estimating includes the step of re-computing a slope of the current line.

2. A method of preprocessing an electronic ink object comprising the steps of:

(a) segmenting the electronic ink object comprising at least one ink stroke into at least one line by performing the steps of;

(i) identifying a plurality of features for each ink stroke of the electronic ink object; and

(ii) classifying each ink stroke as part of a new line,current line;

or a previous line

(b) estimating a writing angle of each line;

(c) rotating each line to make horizontal a centerline of the line; and

wherein if the ink stroke is part of the current line, the step of estimating includes the step of re-computing a slope of a centerline of the current line using a Least Mean Squares algorithm.

3. A method of preprocessing an electronic ink object comprising the steps of:

(a) segmenting the electronic ink object comprising at least one ink stroke into at least one line by performing the steps of;

(i) identifying a plurality of features for each ink stroke of the electronic ink object; and

(ii) classifying each ink stroke as part of a new line, a current line;

or a previous line

(b) estimating a writing angle of each line;

(c) rotating each line to make horizontal a centerline of the line; and

wherein if the ink stroke is part of the previous line, the step of estimating includes the step of re-computing a slope of the previous line.

4. A method of preprocessing an electronic ink object comprising the steps of:

(a) segmenting the electronic ink object comprising at least one ink stoke into at least one line by performing the steps of;

(i) identifying a plurality of features for each ink stroke of the electronic ink object; and

(ii) classifying each ink stroke as part of a new line, a current line, or a previous line

(b) estimating a writing angle of each line;

(c) rotating each line to make horizontal a centerline of the line; and

wherein if the ink stroke is part of the previous line, the step of estimating includes the step of re-computing a slope of a centerline of the previous line using a Least Mean Squares algorithm.