SYSTEMS, METHODS, AND COMPUTER-READABLE MEDIA FOR CAPTURING A SIGNATURE FOR USE IN A DOCUMENT

• US 20120093409A1
• Filed: 10/19/2010
• Published: 04/19/2012
• Est. Priority Date: 10/19/2010
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Sarnoff, Matthew
• Granted Patent: US 8,542,889 B2
• Time in Patent Office: Days
• US Class Current: 382/173
• CPC Class Codes: G06V 30/10 Character recognition
• CPC Class Codes: G06V 30/1456 based on user interactions
• CPC Class Codes: G06V 40/30 Writer recognition; Reading and verifying signatures
• CPC Class Codes: G06V 40/33 based only on signature image, e.g. static signature recognition
• CPC Class Codes: H04N 1/195 the array comprising a two-dimensional array or a combination of two-dimensional arrays
• CPC Class Codes: H04N 1/19594 using a television camera or a still video camera

Abstract

Systems, methods, and computer-readable media are provided for capturing a signature, and placing a representation of the captured signature in an appropriate field of a document. A camera or other appropriate sensor can capture an image of a signature provided by a user on a piece of paper. The signature can be digitized to create a representation that a device may use in a displayed document. To determine where to place the representation, a horizontal line of a document can be identified by selectively rendering portions of the document adjacent to an input position, and identifying one or more boundaries for a detected horizontal line. The representation can be scaled to fit in a detected field of the document.

Claims

1. A method for creating a digital representation of a signature, the method comprising:

capturing an image of a signature, wherein the signature is aligned with a reference line associated with the image;

identifying a top boundary within the image for the signature, wherein the top boundary comprises a row having a particular amount of light portions;

identifying a bottom boundary within the image for the signature, wherein the bottom boundary comprises a row having a particular amount of light portions, and wherein the reference line is positioned between the top boundary and the bottom boundary; and

applying a vectorization process to portions of the captured image that are between the top boundary and the bottom boundary to create a representation of the signature.

2. The method of claim 1, further comprising:

directing a user to position a signature provided on an object opposite a camera such that the signature is aligned with the reference line.

3. The method of claim 2, further comprising:

displaying a preview of the image of the signature in a display window, wherein the display window comprises the reference line.

4. The method of claim 3, further comprising:

directing a user to move the object relative to the camera so that the signature is aligned with the reference line in the display window.

5. The method of claim 1, further comprising:

converting individual pixels of the captured image to black and white pixels using a thresholding function.

6. The method of claim 5, further comprising:

identifying a central row of pixels in the captured image corresponding to the reference line; and

identifying a closest row of pixels above the central row of pixels that comprises a consecutive sequence of white pixels of at least a threshold length, and for which a threshold number of additional rows comprise a consecutive sequence of white pixels, wherein the top boundary comprises the identified closest row of pixels.

7. The method of claim 6, wherein:

the consecutive sequence of white pixels comprises at least thirty white pixels.

8. An electronic device, comprising:

a camera operative to capture an image of a signature provided on a substrate;

display circuitry operative to provide a portion of the captured image in a display window; and

control circuitry operative to;

process the captured image to create a black and white image of the signature;

identify an upper boundary for the signature;

identify a lower boundary for the signature; and

generate a vector representation of the black portions of the image between the upper boundary and the lower boundary, wherein the vector representation corresponds to the signature.

9. The electronic device of claim 8, wherein the control circuitry is further operative to:

convert a captured color image to a grayscale image; and

apply an adaptive thresholding function to the grayscale image to create the black and white image of the signature.

10. The electronic device of claim 8, wherein the control circuitry is further operative to:

identify a position of a reference line provided on the display window relative to the captured image;

identify the upper boundary above the reference line; and

identify the lower boundary below the reference line.

11. The electronic device of claim 10, wherein the control circuitry is further operative to:

identify a reference row of pixels corresponding to the reference line;

successively select each row of pixels above the identified reference row of pixels; and

identify the first row of the successively selected rows of pixels that comprises a sequence of pixels corresponding to the upper boundary.

12. The electronic device of claim 11, wherein the sequence of pixels comprises a consecutive series of white pixels.

13. The electronic device of claim 8, wherein the control circuitry is further operative to:

generate the vector representation of the signature based on the portion of the image provided in the display window.

14. The electronic device of claim 8, wherein:

the vector representation reproduces changes in line thickness and velocity of at least one stroke of the signature.

15. A method for digitizing a signature, the method comprising:

capturing a color image of a signature;

processing the image to generate a black and white image corresponding to the captured image;

identifying a reference line for aligning the signature; and

applying a raster-to-vector process to the portion of the black and white image in regions adjacent to the reference line to generate a representation of the signature.

16. The method of claim 15, further comprising:

identifying rows in the black and white image that comprise black elements;

identifying an upper boundary above the identified rows; and

identifying a lower boundary below the identified rows.

17. The method of claim 15, further comprising:

encrypting the representation to prevent unauthorized use of the representation.

18. The method of claim 17, further comprising:

associating the encrypted representation with a particular user.

19. The method of claim 15, wherein:

associating the representation with a particular application, wherein only the particular application can make use of the representation.

20. A computer-readable medium comprising computer program logic recorded thereon for:

capturing an image of a signature, wherein the signature is aligned with a reference line associated with the image;

identifying a top boundary for the signature, wherein the top boundary comprises a first row of the image having a first particular amount of light portions;

identifying a bottom boundary for the signature, wherein the bottom boundary comprises a second row of the image having a second particular amount of light portions, and wherein the reference line is positioned between the top boundary and the bottom boundary; and

applying a vectorization process to portions of the captured image that are between the top boundary and the bottom boundary to create a representation of the signature.