Analyzing tabular structures in expression recognition

• US 7,447,360 B2
• Filed: 06/20/2005
• Issued: 11/04/2008
• Est. Priority Date: 09/22/2004
• Status: Expired due to Fees

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Huang, Lei, Li, Yue, Wang, Jian
• Primary Examiner(s): Ahmed; Samir A
• Assistant Examiner(s): Abdi; Amara
• Application Number:
  US11/155,783
• Publication Number:
  US 20060062469A1
• Time in Patent Office: 1,233 Days
• Field of Search: 382/186, 382/187
• US Class Current: 382/186
• CPC Class Codes: G06V 30/1423 the instrument generating sequences of position coordinates corresponding to handwriting preprocessing or recognising digital ink G06V30/32

Abstract

A mechanism for recognizing and inputting handwritten mathematical expressions into a computer by providing part of a multi-path framework is described. The part of the multi-path framework is tabular structure analysis component that is designed to determine tabular structures, such as ones defined by brackets, within handwritten mathematical expressions. A method for determining tabular structures in a handwritten mathematical expression includes determining whether a symbol representative of input strokes corresponds to a tabular structure associated with a mathematical expression. The tabular structure may be a matrix or multi-line expression. The method includes dividing input strokes into rows and columns and determining the existence of one or more brackets that define a tabular structure.

Claims

1. A system for handwritten mathematical expression recognition, the system comprising a tabular structure analysis component configured to determine whether a symbol representative of input strokes corresponds to a tabular structure associated with a mathematical expression

wherein upon determining that the symbol corresponds to a tabular structure, the tabular structure analysis component further configured to divide the input strokes into rows and columns in accordance with a size of the tabular structure;

wherein the tabular structure analysis component is further configured to determine whether at least one bracket exists; and

wherein the tabular structure analysis component is further configured to determine whether to merge one of;

at least two of the rows and at least two of the columns.

2. The system of claim 1, wherein the tabular structure is one of a matrix and a multi-line expression.

3. A system for handwritten mathematical expression recognition, the system comprising a tabular structure analysis component configured to determine whether a symbol representative of input strokes corresponds to a tabular structure associated with a mathematical expression

wherein upon determining that the symbol corresponds to a tabular structure, the tabular structure analysis component further configured to divide the input strokes into rows and columns in accordance with a size of the tabular structure;

wherein the tabular structure analysis component is further configured to determine whether at least one bracket exists; and

wherein upon determining that only one bracket exists, the tabular structure is identified as a multi-line expression.

4. The system of claim 3, wherein upon determining that only one bracket exists, the tabular structure analysis component is further configured to merge the columns into one column.

5. A system for handwritten mathematical expression recognition, the system comprising a tabular structure analysis component configured to determine whether a symbol representative of input strokes corresponds to a tabular structure associated with a mathematical expression

wherein upon determining that the symbol corresponds to a tabular structure, the tabular structure analysis component further configured to divide the input strokes into rows and columns in accordance with a size of the tabular structure;

wherein the tabular structure analysis component is further configured to determine whether at least one bracket exists; and

wherein upon determining that two brackets exist, the tabular structure is identified as a matrix.

6. A system for handwritten mathematical expression recognition, the system comprising a tabular structure analysis component configured to determine whether a symbol representative of input strokes corresponds to a tabular structure associated with a mathematical expression

wherein upon determining that the symbol corresponds to a tabular structure, the tabular structure analysis component further configured to divide the input strokes into rows and columns in accordance with a size of the tabular structure;

wherein the tabular structure analysis component is further configured to determine whether at least one bracket exists; and

wherein the tabular structure analysis component is further configured to determine whether at least one column includes an empty cell.

7. The system of claim 6, wherein upon determining that at least one column includes an empty cell, the tabular structure analysis component is further configured to merge the empty cell with another cell.

8. The system of claim 6, wherein the tabular structure analysis component is further configured to store the symbol in a parse tree corresponding to multiple candidate outputs.

9. A method for analyzing a handwritten mathematical expression for a tabular structure, the method comprising a step of determining whether a symbol representative of input strokes corresponds to a tabular structure associated with a mathematical expression

wherein upon determining that the symbol corresponds to a tabular structure, the method further comprising a step of dividing the input strokes into rows and columns in accordance with the size of the tabular structure;

and

wherein upon determining that only one bracket exists, the method further comprises a step of merging the columns into one column.

10. The method of claim 9, wherein the tabular structure is one of a matrix and a multi-line expression.

11. A method for analyzing a handwritten mathematical expression for a tabular structure, the method comprising a step of determining whether a symbol representative of input strokes corresponds to a tabular structure associated with a mathematical expression

wherein upon determining that the symbol corresponds to a tabular structure, the method further comprising a step of dividing the input strokes into rows and columns in accordance with the size of the tabular structure;

and

further comprising a step of determining whether at least one column includes an empty cell.

12. The method of claim 11, wherein upon determining that at least one column includes an empty cell, the method further comprising a step of merging the empty cell with another cell.