Apparatus and method for detecting secure document

• US 7,945,100 B2
• Filed: 06/07/2006
• Issued: 05/17/2011
• Est. Priority Date: 06/08/2005
• Status: Expired due to Fees

• Current Assignee: S-Printing Solution Co., Ltd. (Samsung Electronics Co. Ltd.)
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Yi, Jong-Hyon
• Primary Examiner(s): Werner; Brian P
• Assistant Examiner(s): Rosario; Dennis
• Application Number:
  US11/447,883
• Publication Number:
  US 20060280353A1
• Time in Patent Office: 1,805 Days
• Field of Search: 382/199, 382/219, 382/220, 382/135, 382/216, 382/103, 382/218, 382/222, 358/1.14
• US Class Current: 382/219
• CPC Class Codes: G06V 10/56 relating to colour
• CPC Class Codes: G06V 10/758 Involving statistics of pixels or of feature values, e.g. histogram matching
• CPC Class Codes: H04N 1/00843 based on recognising a copy prohibited original, e.g. a banknote pattern authentication and markers therefor, forgery detection G06V20/95; character recognition G06V30/10; document-oriented image-based pattern recognition G06V30/40; testing paper currency or similar valuable papers for genuineness G07D7/00
• CPC Class Codes: H04N 1/00848 by detecting a particular original
• CPC Class Codes: H04N 1/00875 Inhibiting reproduction, e.g. by disabling reading or reproduction apparatus

Abstract

An apparatus and method for detecting a secure document is provided. The apparatus includes an image input unit which receives the image of a document; an edge image detecting unit which detects an edge image of the document having a predetermined size; a similarity checking unit which checks the similarity between the detected edge image and comparative edge images of secure documents which are previously stored; and a document attribute determining unit which determines whether the document is one of the secure documents according to the result of the similarity checking unit.

Claims

1. An apparatus for detecting a secure document, comprising:

an image input unit for receiving an image of a document;

an edge image detecting unit for detecting a corner image of the document;

an orientation detecting unit for calculating an orientation of the document using the image including the detected corner;

an image detecting unit for detecting a corner image of a predetermined size by using the detected orientation;

a similarity checking unit for checking the similarity between the detected corner image and previously stored comparative corner images of secure documents; and

a document attribute determining unit for determining whether the document is one of the secure documents according to a result of the similarity checking,

wherein the previously stored comparative corner images are rearranged and stored in a number of predetermined orientations,

wherein the similarity checking unit comprises;

a color value detecting unit for detecting the representative color values of the detected corner image;

a color value comparing unit for comparing the detected representative color values of the corner image with the representative color values of the comparative corner images and selecting a comparative corner image that have representative color values similar to the detected representative color values of the corner image; and

a pixel value comparing unit for comparing color values of the pixels of the detected corner image with color values of the pixels of the selected comparative image according to a result of the color value comparing.

2. The apparatus of claim 1, wherein the image input unit comprises:

an image sensing unit for sensing the image of the document; and

a buffering unit for storing a number of lines of the sensed image and outputting the sensed image to the edge image detecting unit.

3. The apparatus of claim 1, wherein the color value detecting unit detects at least one of a first red value obtained by averaging the red pixel values of the detected edge image, a first green value obtained by averaging the green pixel values of the detected edge image, and a first blue value obtained by averaging the blue pixel values of the detected edge image as the representative color values.

4. The apparatus of claim 3, wherein the color value comparing unit compares absolute values of the respective differences between at lest one of the first red value, the first green value and the first blue value, and at least one of a first comparative red value, a first comparative green value and a first comparative blue value as the representative color values of at least one of the comparative edge images with first, second, and third threshold values, respectively.

5. The apparatus of claim 3, wherein the color value comparing unit compares a sum of the absolute values of the respective differences between at least one of the first red value, the first green value and the first blue value, and at least one of a first comparative red value, a first comparative green value and a first comparative blue value as the representative color values of at least one of the comparative edge images with a fourth threshold value.

6. The apparatus of claim 1, wherein the color value detecting unit detects at least one of a second red value occurring with a maximum frequency among red pixel values of the detected edge image, a second green value occurring with a maximum frequency among the green pixel values of the detected edge image, and a second blue value occurring with a maximum frequency among the blue pixel values of the detected edge image as the representative color values.

7. The apparatus of claim 6, wherein the color value comparing unit compares the absolute values of the respective differences between at least one of the second red value, the second green value and the second blue value, and at least one of a second comparative red value, a second comparative green value and a second comparative blue value as the representative color values of at least one of the comparative edge images with fifth, sixth, and seventh threshold values, respectively.

8. The apparatus of claim 6, wherein the color value comparing unit compares the sum of the absolute values of the respective differences between at least one of the second red value, the second green value and the second blue value, and at least one of a second comparative red value, a second comparative green value and a second comparative blue value as the representative color values of at least one of the comparative edge images with an eighth threshold value.

9. The apparatus of claim 1, wherein the color value detecting unit detects at least one of a third red value corresponding to a median of the red pixel values of the detected edge image, a third green value corresponding to a median of the green pixel values of the detected edge image, and a third blue value corresponding to a median of the blue pixel values of the detected edge image as the representative color values.

10. The apparatus of claim 9, wherein the color value comparing unit compares the absolute values of the respective differences between at least one of the third red value, the third green value and the third blue value, and at least one of a third comparative red value, a third comparative green value and a third comparative blue value as the representative color values of at least one of the comparative edge images with ninth, tenth, and eleventh threshold values, respectively.

11. The apparatus of claim 9, wherein the color value comparing unit compares the sum of the absolute values of the respective differences between at least one of the third red value, the third green value and the third blue value, and at least one of a third comparative red value, a third comparative green value and a third comparative blue value as the representative color values of at least one of the comparative edge images with a twelfth threshold value.

12. The apparatus of claim 1, further comprising:

an image formation stop instructing unit which stops the formation of the document according to the result of the document attribute determining unit.

13. The apparatus of claim 1, wherein the secure document is paper money.

14. A method of detecting a secure document, comprising:

receiving an image of a document;

detecting a corner image of the document;

calculating an orientation of the document using the image including the detected corner;

detecting a corner image of a predetermined size by using the detected orientation;

checking a similarity between the detected corner image and comparative corner images of secure documents which are previously stored; and

determining whether the document is one of the secure documents according to the similarity,

wherein at least one programmed controller performs at least one of the receiving step, the detecting step, the calculating step, the detecting step, the checking step and the determining step,

wherein the comparative edge images are rearranged and stored in a number of predetermined orientations,

wherein the checking of the similarity between the detected corner image and the comparative corner images comprises;

detecting representative color values of the detected corner image;

checking to determine whether at least one of the comparative corner images comprises representative color values similar to the representative color values of the detected corner image;

selecting a comparative corner image comprising the representative color values similar to the representative color values of the detected corner image; and

comparing color values of the pixels of the detected corner image with color values of the pixels of the selected comparative corner image.

15. The method of claim 14, wherein the receiving of the image of the document comprises:

sensing the image of the document; and

storing and outputting a number of lines of the sensed image.

16. The method of claim 14, wherein the detecting of the representative color values of the detected edge image comprises detecting at least one of a first red value obtained by averaging the red pixel values of the detected edge image, a first green value obtained by averaging the green pixel values of the detected edge image, and a first blue value obtained by averaging the blue pixel values of the detected edge image as the representative color values.

17. The method of claim 16, wherein the selecting of the comparative edge image comprises comparing absolute values of the respective differences between at least one of the first red value, the first green value and the first blue value, and at least one of a first comparative red value, a first comparative green value and a first comparative blue value as the representative color values of at least one of the comparative edge images with first, second, and third threshold values, respectively.

18. The method of claim 17, wherein the selecting of the comparative edge image comprises comparing a sum of the absolute values of the respective differences between at least one of the first red value, the first green value and the first blue value, and at least one of a first comparative red value, a first comparative green value and a first comparative blue value as the representative color values of at least one of the comparative edge images with a fourth threshold value.

19. The method of claim 14, wherein the detecting of representative color values of the detected edge image comprises detecting at least one of a second red value occurring with a maximum frequency among red pixel values of the detected edge image, a second green value occurring with a maximum frequency among the green pixel values of the detected edge image, and a second blue value occurring with a maximum frequency among the blue pixel values of the detected edge image as the representative color values.

20. The method of claim 19, wherein the selecting of the comparative edge image comprises comparing absolute values of the respective differences between at least one of the second red value, the second green value and the second blue value, and at least one of a second comparative red value, a second comparative green value and a second comparative blue value as the representative color values of at least one of the comparative edge images with fifth, sixth, and seventh threshold values, respectively.

21. The method of claim 20, wherein the selecting of the comparative edge image comprises comparing the sum of the absolute values of the respective differences between at least one of the second red value, the second green value, and the second blue value, and at least one of a second comparative red value, a second comparative green value and a second comparative blue value as the representative color values of at least one of the comparative edge images with an eighth threshold value.

22. The method of claim 19, wherein the detecting of representative color values of the detected edge image comprises detecting at least one of a third red value corresponding to a median of the red pixel values of the detected edge image, a third green value corresponding to a median of the green pixel values of the detected edge image, and a third blue value corresponding to a median of the blue pixel values of the detected edge image as the representative color values.

23. The method of claim 22, wherein the selecting of the comparative edge image comprises comparing absolute values of the respective differences between at least one of the third red value, the third green value and the third blue value, and at least one of a third comparative red value, a third comparative green value and a third comparative blue value as the representative color values of at least one of the comparative edge images with ninth, tenth, and eleventh threshold values, respectively.

24. The method of claim 22, wherein the selecting of the comparative edge image comprises comparing a sum of the absolute values of the respective differences between at least on of the third red value, the third green value and the third blue value, and at least one of a third comparative red value, a third comparative green value and a third comparative blue value as the representative color values of at least one of the comparative edge images with a twelfth threshold value.

25. The method of claim 14, further comprising:

stopping the image formation of the document if the document is determined to comprise the secure document.

26. The method of claim 14, wherein the secure document comprises paper money.

27. A non-transitory computer-readable medium comprising a computer program for performing the method of claim 14.