METHOD OF CORRECTING ORIENTATION OF AN IMAGE IN AUTOMATIC PRINTING, AND AN IMAGE FORMING METHOD AND IMAGE FORMING APPARATUS THEREOF

• US 20090317000A1
• Filed: 06/23/2009
• Published: 12/24/2009
• Est. Priority Date: 06/23/2008
• Status: Active Grant

• Current Assignee: HP Printing Korea Co., Ltd. (HP Inc.)
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: EFIMOV, Sergei V.
• Granted Patent: US 8,437,576 B2
• Time in Patent Office: Days
• US Class Current: 382/216
• CPC Class Codes: G06V 30/10 Character recognition
• CPC Class Codes: G06V 30/1463 Orientation detection or correction, e.g. rotation of multiples of 90 degrees

Abstract

An image forming method includes receiving an image, detecting a text area from the image, transforming the detected text area into a binary image and calculating an asymmetry parameter of the binary image, and detecting orientation of the image based on the calculated asymmetry parameter.

Claims

1. A method of detecting orientation of an image, the method comprising:

selecting text blocks;

testing whether the number of text blocks N is less than a pre-set threshold T;

if the number of text blocks N is less than the pre-set threshold T, not detecting the orientation of the document;

if the number of text blocks N is greater than the pre-set threshold T, filling non-text areas with white color;

transforming the image into a binary image;

calculating asymmetry parameters of text (asym0, asym90);

calculating a horizontal coefficient (ah) and a vertical coefficient (av);

testing whether the parameter (asym0) is greater than zero and whether the horizontal coefficient (ah) is greater than the vertical coefficient (av);

if a result of testing whether the parameter (asym0) is greater than zero and the horizontal coefficient (ah) is greater than the vertical coefficient (av) is positive, determining that the image has correct orientation;

if a result of testing whether the parameter (asym0) is greater than zero and the horizontal coefficient (ah) is greater than the vertical coefficient (av) is negative, testing whether the parameter (asym0) is less than zero and whether the horizontal coefficient (ah) is greater than the vertical coefficient (av);

if a result of testing whether the parameter (asym0) is less than zero and the horizontal coefficient (ah) is greater than the vertical coefficient (av) is positive, turning the image by 180 degrees;

if a result of testing whether the parameter (asym0) is less than zero and the horizontal coefficient (ah) is greater than the vertical coefficient (av) is negative, testing whether the parameter (asym90) is greater than zero and the horizontal coefficient (ah) is less than the vertical coefficient (av);

if a result of testing whether the parameter (asym90) is greater than zero and the horizontal coefficient (ah) is less than the vertical coefficient (av) is positive, turning the image by 90 degrees; and

if a result of testing whether the parameter (asym90) is greater than zero and the horizontal coefficient (ah) is less than the vertical coefficient (av) is negative, turning the image by 270 degrees.

2. The method of claim 1, wherein the method of detecting the orientation is performed prior to generating a copy for the image.

3. An image forming method of an image forming apparatus, the image forming method comprising:

receiving an image;

detecting a text area of the image;

transforming the detected text area into a binary image and calculating an asymmetry parameter of the binary image; and

detecting orientation of the image based on the calculated asymmetry parameter.

4. The image forming method of claim 3, further comprising:

if the detected orientation of the image differs from a default direction, adjusting the orientation of the image.

5. The image forming method of claim 4, further comprising printing the image the orientation of which is adjusted.

6. The image forming method of claim 4, further comprising storing the image the orientation of which is adjusted.

7. The image forming method of claim 3, wherein the receiving the image comprises scanning an image through a scanning unit of the image forming apparatus.

8. The image forming method of claim 3, wherein the calculating the asymmetry parameter comprises calculating an asymmetry coefficient, a horizontal coefficient, and a vertical coefficient of the text.

9. The image forming method of claim 3, wherein the detecting the orientation comprises detecting whether the image is in a horizontal mode (portrait) or a vertical mode (landscape) and whether the image is oriented up or down in each mode.

10. An image forming apparatus comprising:

a text detection unit to detect a text area of an input image;

a coefficient calculation unit to transform the detected text area into a binary image and to calculate an asymmetry parameter of the binary image; and

an orientation detection unit to detect an orientation of the image based on the calculated asymmetry parameter.

11. The image forming apparatus of claim 10, further comprising an orientation adjustment unit to adjust the orientation of the input image if the detected orientation of the image differs from a default direction.

12. The image forming apparatus of claim 11, further comprising a print engine unit to print the image the orientation of which is adjusted.

13. The image forming apparatus of claim 11, further comprising a storage unit to store the image the orientation of which is adjusted.

14. The image forming apparatus of claim 10, further comprising a scanning unit to scan an image,

wherein the text detection unit receives the image scanned by the scanning unit.

15. The image forming apparatus of claim 10, wherein the coefficient calculation unit calculates an asymmetry coefficient, a horizontal coefficient and a vertical coefficient of the text.

16. The image forming apparatus of claim 10, wherein the orientation detection unit detects whether the image is in a horizontal mode (portrait) or a vertical mode (landscape) and whether the image is oriented up or down in each mode.