Apparatus and method for detecting secure document

• US 20060280353A1
• Filed: 06/07/2006
• Published: 12/14/2006
• Est. Priority Date: 06/08/2005
• Status: Active Grant

• Current Assignee: S-Printing Solution Co., Ltd. (Samsung Electronics Co. Ltd.)
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Yi, Jong-Hyon
• Granted Patent: US 7,945,100 B2
• Time in Patent Office: Days
• US Class Current: 382/135
• 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 an edge image of the document;

a similarity checking unit for checking the similarity between the detected edge image and previously stored comparative edge 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.

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 edge image detecting unit comprises:

an edge detecting unit for detecting an edge of the document;

an orientation detecting unit for detecting the orientation of the document using the image of the detected edge; and

an image detecting unit for detecting the edge using the detected orientation.

4. The apparatus of claim 1, wherein the similarity checking unit comprises:

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

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

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

5. The apparatus of claim 4, 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.

6. The apparatus of claim 5, wherein the color value comparing unit compares the 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.

7. The apparatus of claim 5, wherein the color value comparing unit compares the 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.

8. The apparatus of claim 4, wherein the color value detecting unit detects at least one of a second red value occurring with a maximum frequency among the 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.

9. The apparatus of claim 8, 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.

10. The apparatus of claim 8, 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.

11. The apparatus of claim 4, 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.

12. The apparatus of claim 11, 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.

13. The apparatus of claim 11, 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.

14. The apparatus of claim 1, wherein the comparative images are rearranged and stored according to a referenced orientation.

15. 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.

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

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

receiving an image of a document;

detecting an edge image of the document;

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

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

18. The method of claim 17, 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.

19. The method of claim 17, wherein the detecting of the edge image of the document comprises:

detecting an edge of the document;

detecting an orientation of the document using the image of the detected edge; and

detecting the edge image using the detected orientation.

20. The method of claim 17, wherein the checking of the similarity between the detected edge image and the comparative edge images comprises:

detecting representative color values of the detected edge image;

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

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

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

21. The method of claim 20, 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.

22. The method of claim 21, wherein the selecting of the comparative edge image comprises comparing 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 first, second, and third threshold values, respectively.

23. The method of claim 21, 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 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.

24. The method of claim 20, 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 the 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.

25. The method of claim 24, wherein the selecting of the comparative edge image comprises comparing 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.

26. The method of claim 24, 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.

27. The method of claim 24, 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.

28. The method of claim 27, wherein the selecting of the comparative edge image comprises comparing 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.

29. The method of claim 27, wherein the selecting of the comparative edge image comprises comparing the 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.

30. The method of claim 17, wherein the comparative edge images are rearranged and stored according to an orientation.

31. The method of claim 17, further comprising:

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

32. The method of claim 17, wherein the secure document comprises paper money.

33. A computer-readable medium comprising a computer program for performing the method of claim 17.