Image processing apparatus and method, computer program, and recording medium

• US 20030063319A1
• Filed: 09/27/2002
• Published: 04/03/2003
• Est. Priority Date: 10/01/2001
• Status: Active Grant

• Current Assignee: Canon Ayutthaya Limited (Canon Inc.)
• Original Assignee: Canon Ayutthaya Limited (Canon Inc.)
• Inventors: Miyake, Nobutaka, Umeda, Kiyoshi, Kusakabe, Minoru
• Granted Patent: US 7,187,476 B2
• Time in Patent Office: Days
• US Class Current: 358/3.28
• CPC Class Codes: G06K 15/02 using printers
• CPC Class Codes: G06K 2215/0082 Architecture adapted for a particular function
• CPC Class Codes: G06T 1/0064 Geometric transfor invariant watermarking, e.g. affine transform invariant
• CPC Class Codes: H04N 1/32149 Methods relating to embedding, encoding, decoding, detection or retrieval operations
• CPC Class Codes: H04N 1/32352 Controlling detectability or arrangements to facilitate detection or retrieval of the embedded information, e.g. using markers for decoding, detection or retrieval operations H04N1/32149 and subgroups take precedence
• CPC Class Codes: H04N 2201/3269 of machine readable codes or marks, e.g. bar codes or glyphs
• CPC Class Codes: H04N 2201/327 which are undetectable to the naked eye, e.g. embedded codes
• CPC Class Codes: H04N 2201/3271 Printing or stamping

Abstract

This invention is an image processing apparatus capable of adding a reference frame for accurately specifying an image region printed on a printing medium. An image forming unit (13) converts an input image for printing into that of a predetermined resolution. An additional information multiplexer (14) embeds additional information in each predetermined region of the resolution-converted image. A reference frame addition unit 15 adds a predetermined reference frame to the perimeter of the image in which the additional information is embedded. A printer (16) prints the image having the additional information embedded in it and the reference frame onto a printing medium, and outputs a printed image (17).

Claims

1. An image processing apparatus comprising:

additional information multiplexing means for embedding additional information in an image;

frame adding means for adding a predetermined frame to the perimeter of the image in which the additional information is embedded; and

printing means for printing, on a printing medium, the image having the additional information embedded therein and the frame.

2. The apparatus according to claim 1, further comprising resolution converting means for converting the image into that of a predetermined resolution.

3. The apparatus according to claim 1, further comprising mark adding means for adding, onto said frame, a predetermined mark corresponding to additional information embedded in each predetermined region of the image.

4. The apparatus according to claim 3, wherein said marks are blank portions formed at predetermined intervals on said frame and each having a predetermined length.

5. The apparatus according to claim 1, wherein said frame is added at a predetermined distance from the edges of the image.

6. The apparatus according to claim 2, wherein said resolution converting means converts the resolution of the image by a value at least twice a predetermined distortion amount when the printed product is input.

7. An image processing apparatus comprising:

input means for inputting a printed product formed by printing, on a printing medium, an image having additional information embedded therein, by adding a predetermined frame to the perimeter of the image;

frame detecting means for detecting a predetermined portion of said frame from the input image;

apex calculating means for calculating the apexes of the image from the detected predetermined portion of said frame;

position calculating means for calculating a predetermined position in the image on the basis of the calculated apex positions; and

separating means for separating the additional information embedded in the image on the basis of the calculated predetermined position.

8. The apparatus according to claim 7, wherein

a predetermined mark corresponding to the additional information is added onto said frame, and

the apparatus further comprises mark detecting means for detecting said mark.

9. The apparatus according to claim 8, wherein said position calculating means comprises:

X-coordinate calculating means for calculating the X-coordinate of a predetermined position by using the X-coordinate of a mark present in a direction perpendicular to the predetermined position; and

Y-coordinate calculating means for calculating the Y-coordinate of the predetermined position by using the Y-coordinate of said mark present in the direction perpendicular to the predetermined position.

10. An image processing method of printing an image on a predetermined printing medium, comprising:

the additional information multiplexing step of embedding additional information in the image;

the frame addition step of adding a predetermined frame to the perimeter of the image in which the additional information is embedded; and

the printing step of printing, on a printing medium, the image having the additional information embedded therein and the frame.

11. The method according to claim 10, further comprising the resolution conversion step of converting the image into that of a predetermined resolution.

12. The method according to claim 10, further comprising the mark addition step of adding, onto the frame, a predetermined mark corresponding to additional information embedded in each predetermined region of the image.

13. The method according to claim 12, wherein the marks are blank portions formed at predetermined intervals on the frame and each having a predetermined length.

14. The method according to claim 10, wherein the frame is added at a predetermined distance from the edges of the image.

15. The method according to claim 11, wherein the resolution conversion step comprises converting the resolution of the image by a value at least twice a predetermined distortion amount when the printed product is input.

16. An image processing method of optically reading a printed product formed by printing, on a printing medium, an image having additional information embedded therein, by adding a predetermined frame to the perimeter of the image, comprising:

the frame detection step of detecting a predetermined portion of the frame from the image;

the apex calculation step of calculating the apexes of the image from the detected predetermined portion of the frame;

the position calculation step of calculating a predetermined position in the image on the basis of the calculated apex positions; and

the separation step of separating the additional information embedded in the image on the basis of the calculated predetermined position.

17. The method according to claim 16, wherein

a predetermined mark corresponding to the additional information is added onto the frame, and

the method further comprises the mark detection step of detecting the mark.

18. The method according to claim 17, wherein the position calculation step comprises:

the X-coordinate calculation step of calculating the X-coordinate of a predetermined position by using the X-coordinate of a mark present in a direction perpendicular to the predetermined position; and

the Y-coordinate calculation step of calculating the Y-coordinate of the predetermined position by using the Y-coordinate of the mark present in the direction perpendicular to the predetermined position.

19. A computer program for controlling an image processing apparatus comprising printing means for printing a predetermined image, comprising:

a program code of the additional information multiplexing step of embedding additional information in the image;

a program code of the frame addition step of adding a predetermined frame to the perimeter of the image in which the additional information is embedded; and

a program code of the printing step of printing, on a printing medium, the image having the additional information embedded therein and the frame.

20. A recording medium storing the computer program defined in claim 19.

21. An image processing apparatus comprising optical reading means for optically reading a printing medium on which an image having additional information embedded therein is printed, and separating/restoring means for separating and restoring the additional information from the read image, further comprising:

frame detecting means for detecting a frame including reference marks formed at predetermined intervals around an image region printed on said printing medium;

apex specifying means for specifying the apexes of the image region on the basis of the detected frame;

reference mark detecting means for detecting reference marks between two adjacent apexes in turn from the side of one apex; and

image region calculating means for calculating the size of the image on the basis of the detected reference marks.

22. The apparatus according to claim 21, wherein said reference mark detecting means comprises:

search region setting means for setting, between two adjacent apexes, a reference mark search region having a predetermined size in order from an apex as a start point; and

reference mark detecting means for detecting, as a reference mark, the position of a pixel at which an output value is a maximum when an enhancement filter is used in the search region.

23. The apparatus according to claim 22, wherein said reference mark detecting means further comprises:

distance calculating means for calculating the distance between said detected reference mark and an apex as an end point;

determining means for determining whether the calculated distance is not less than a predetermined threshold value;

first integrating means which, if the calculated distance is not less than the predetermined threshold value, calculates an integrated distance by multiplying the number of reference marks, from a reference mark detected first to a reference mark detected last, by the size of a block in which the additional information is embedded; and

second integrating means which, if the calculated distance is less than the predetermined threshold value, calculates the size of the image by further adding, to the integrated distance, the distance from the last detected reference mark to the apex as the end point.

24. The apparatus according to claim 21, wherein said reference marks form a dot-like scale.

25. The apparatus according to claim 21, wherein said reference marks have a color close to the color of the printing surface of said printing medium.

26. The apparatus according to claim 21, further comprising converting means which, on the basis of the calculated size of the image, converts the image read by said optical reading means into the size of the image before the image is printed on said printing medium.

27. The apparatus according to claim 21, further comprising:

resolution converting means for converting an image into that of a predetermined resolution;

additional information multiplexing means for embedding additional information in the resolution-converted image;

reference mark adding means for adding, with a predetermined spacing, a frame having a width of not less than one pixel to the perimeter of an image in which additional information is embedded, and adding reference marks at predetermined intervals onto said frame; and

printing means for printing the image and said frame including said reference marks on a printing medium.

28. An image processing method comprising:

the first step of optically reading a printing medium on which an image having additional information embedded therein is printed, a frame including reference marks formed at predetermined intervals being further formed around an image region printed on the printing medium;

the second step of detecting the frame;

the third step of specifying the apexes of the image region on the basis of the detected frame;

the fourth step of detecting reference marks between two adjacent apexes in turn from the side of one apex;

the fifth step of specifying the size of the image on the basis of the detected reference marks;

the sixth step of converting the image into the size of an image before printing on the basis of the specified size of the image; and

the seventh step of separating and restoring the additional information from the size-converted image.

29. The method according to claim 28, wherein the fourth step further comprises:

the search region setting step of setting, between two adjacent apexes, a reference mark search region having a predetermined size in order from an apex as a start point; and

the reference mark detection step of detecting, as a reference mark, the position of a pixel at which an output value is a maximum when an enhancement filter is used in the search region.

30. The method according to claim 29, wherein the fourth step further comprises:

the distance calculation step of calculating the distance between the detected reference mark and an apex as an end point;

the determination step of determining whether the calculated distance is not less than a predetermined threshold value;

the first integration step which, if the calculated distance is not less than the predetermined threshold value, calculates an integrated distance by multiplying the number of reference marks, from a reference mark detected first to a reference mark detected last, by the size of a block in which the additional information is embedded; and

the second integration step which, if the calculated distance is less than the predetermined threshold value, calculates the size of the image by further adding, to the integrated distance, the distance from the last detected reference mark to the apex as the end point.

31. The method according to claim 28, wherein the reference marks form a dot-like scale.

32. The method according to claim 28, wherein the reference marks have a color close to the color of the printing surface of the printing medium.

33. A computer program for controlling an image processing apparatus for optically reading a printing medium on which an image having additional information embedded therein is printed, a frame including reference marks formed at predetermined intervals being further formed around an image region printed on the printing medium, and separating and restoring the additional information, comprising:

a program code of the first step of optically reading the printing medium;

a program code of the second step of detecting the frame;

a program code of the third step of specifying the apexes of the image region on the basis of the detected frame;

a program code of the fourth step of detecting reference marks between two adjacent apexes in turn from the side of one apex;

a program code of the fifth step of specifying the size of the image on the basis of the detected reference marks;

a program code of the sixth step of converting the image into the size of an image before printing on the basis of the specified size of the image; and

a program code of the seventh step of separating and restoring the additional information from the size-converted image.

34. A recording medium storing the computer program defined in claim 33.