Multi-resolution spatial feature extraction for automatic handwriting recognition

• US 8,989,492 B2
• Filed: 06/04/2012
• Issued: 03/24/2015
• Est. Priority Date: 06/03/2011
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Bellegarda, Jerome R., Dolfing, Jannes G. A.
• Primary Examiner(s): Le, Vu
• Assistant Examiner(s): WOLDEMARIAM, AKLILU K
• Application Number:
  US13/507,118
• Publication Number:
  US 20120308138A1
• Time in Patent Office: 1,023 Days
• Field of Search: 382/115, 382/157, 382/181, 382/185, 382/187, 382/289, 382/296, 345/509, 345/511, 345/202, 345/200
• US Class Current: 382/181
• CPC Class Codes: G06F 18/00 Pattern recognition
• CPC Class Codes: G06V 30/347 Sampling; Contour coding; Stroke extraction
• CPC Class Codes: G06V 30/373 using a special pattern or subpattern alphabet

Abstract

A first technique of recognizing content is disclosed, including: determining a first value representative of a pixel content present at a first set of pixels associated with a first distance from a pixel under consideration; determining a second value representative of a pixel content present at a second set of pixels associated with a second distance from the pixel under consideration; and using the first and second values to compute one or more spatial features associated with the pixel under consideration for purposes of content recognition. A second technique of recognizing content is also disclosed, including: determining, for a pixel, a first value representative of a first feature associated with a set of pixels associated with a first direction from the pixel; and determining, for the pixel, a second value representative of a second feature associated with a set of pixels associated with a second direction from the pixel.

Claims

1. A system of recognizing content, comprising:

a processor configured to;

determine a first value representative of a pixel content present at a first set of pixels of a bitmap associated with a first distance from a pixel under consideration of the bitmap;

determine a second value representative of a pixel content present at a second set of pixels of the bitmap associated with a second distance from the pixel under consideration; and

use the first and second values to compute one or more spatial features associated with the pixel under consideration for purposes of content recognition; and

a memory coupled to the processor and configured to provide the processor with instructions.

2. The system of claim 1, wherein the first value representative of the pixel content present at the first set of pixels associated with the first distance from the pixel under consideration comprises pixel content present at a subset of the first set of pixels.

3. The system of claim 1, wherein the second value representative of the pixel content present at the second set of pixels associated with the second distance from the pixel under consideration comprises pixel content present at a subset of the second set of pixels.

4. The system of claim 1, wherein the processor is further configured to determine, for the pixel, a third value representative of a pixel content present at a third set of pixels of the bitmap associated with a third distance from the pixel.

5. The system of claim 1, wherein the processor is further configured to aggregate the first value and the second value into an aggregate value representative of a pixel content present at the first set of pixels associated with the first distance and the second set of pixels associated with the second distance.

6. A method of recognizing content, comprising:

determining a first value representative of a pixel content present at a first set of pixels of a bitmap associated with a first distance from a pixel under consideration of the bitmap;

determining a second value representative of a pixel content present at a second set of pixels of the bitmap associated with a second distance from the pixel under consideration; and

using the first and second values to compute one or more spatial features associated with the pixel under consideration for purposes of content recognition.

7. The method of claim 6, wherein the first value representative of the pixel content present at the first set of pixels associated with the first distance from the pixel under consideration comprises pixel content present at a subset of the first set of pixels.

8. The method of claim 6, wherein the second value representative of the pixel content present at the second set of pixels associated with the second distance from the pixel under consideration comprises pixel content present at a subset of the second set of pixels.

9. The method of claim 6, further aggregating the first value and the second value into an aggregate value representative of a pixel content present at the first set of pixels associated with the first distance and the second set of pixels associated with the second distance.

10. A non-transitory computer program product for recognizing content, the computer program product being embodied in a computer readable medium and comprising computer instructions for:

determining a first value representative of a pixel content present at a first set of pixels of a bitmap associated with a first distance from a pixel under consideration of the bitmap;

determining a second value representative of a pixel content present at a second set of pixels of the bitmap associated with a second distance from the pixel under consideration; and

using the first and second values to compute one or more spatial features associated with the pixel under consideration for purposes of content recognition.

11. A system of recognizing content, comprising:

a processor configured to;

determine, for a pixel of a bitmap, a first value representative of a first feature associated with a set of pixels of the bitmap associated with a first direction from the pixel in the bitmap; and

determine, for the pixel, a second value representative of a second feature associated with a set of pixels of the bitmap associated with a second direction from the pixel in the bitmap; and

a memory coupled to the processor and configured to provide the processor with instructions.

12. The system of claim 11, wherein determining, for the pixel, the first value representative of the first feature associated with the set of pixels associated with the first direction from the pixel comprises:

determining a first value representative of a pixel content present at a subset of pixels of the bitmap associated with a first distance from the pixel;

determining a second value representative of a pixel content present at a subset of pixels of the bitmap associated with a second distance from the pixel; and

aggregating the first value and the second value into an aggregate value representative of a pixel content present at the subset of pixels associated with the first distance from the pixel and the subset of pixels associated with the second distance from the pixel.

13. The system of claim 12, wherein the first and second distance comprises non-consecutive distances.

14. The system of claim 11, wherein the first direction is one of the following:

north, east, south, or west.

15. The system of claim 14, wherein the second direction is one of north, east, south, or west and different from a direction associated with the first direction.

16. The system of claim 11, wherein the set of pixels associated with the first direction from the pixel comprises a set of contiguous pixels of the bitmap associated with the first direction.

17. The system of claim 11, wherein the set of pixels associated with the second direction from the pixel comprises a set of contiguous pixels of the bitmap associated with the second direction.

18. The system of claim 11, wherein the set of pixels associated with the first direction from the pixel comprises a subset of the set of pixels at one or more distances associated with the first direction.

19. The system of claim 11, wherein the set of pixels associated with the second direction from the pixel comprises a subset of the set of pixels at one or more distances associated with the second direction.

20. A method of recognizing content, comprising:

determining, for a pixel of a bitmap, a first value representative of a first feature associated with a set of pixels of the bitmap associated with a first direction from the pixel in the bitmap; and

determining, for the pixel, a second value representative of a second feature associated with a set of pixels of the bitmap associated with a second direction from the pixel in the bitmap.

21. The method of claim 20, wherein determining, for the pixel, the first value representative of the first feature associated with the set of pixels associated with the first direction from the pixel comprises:

determining a first value representative of a pixel content present at a subset of pixels of the bitmap associated with a first distance from the pixel;

determining a second value representative of a pixel content present at a subset of pixels of the bitmap associated with a second distance from the pixel; and

aggregating the first value and the second value into an aggregate value representative of a pixel content present at the subset of pixels associated with the first distance from the pixel and the subset of pixels associated with the second distance from the pixel.

22. The method of claim 21, wherein the first and second distance comprises non-consecutive distances.

23. The method of claim 21, wherein the first direction is one of the following:

north, east, south, or west.

24. The method of claim 23, wherein the second direction is one of north, east, south, or west and different from a direction associated with the first direction.

25. The method of claim 20, wherein the set of pixels associated with the first direction from the pixel comprises a subset of the set of pixels at one or more distances associated with the first direction.

26. The method of claim 20, wherein the set of pixels associated with the second direction from the pixel comprises a subset of the set of pixels at one or more distances associated with the second direction.

27. A computer program product for recognizing content, the computer program product being embodied in a computer readable medium and comprising computer instructions for:

determining, for a pixel of a bitmap, a first value representative of a first feature associated with a set of pixels of the bitmap associated with a first direction from the pixel in the bitmap; and

determining, for the pixel, a second value representative of a second feature associated with a set of pixels of the bitmap associated with a second direction from the pixel in the bitmap.