Image extracting apparatus, image extracting method and computer readable medium

• US 8,155,443 B2
• Filed: 11/05/2008
• Issued: 04/10/2012
• Est. Priority Date: 04/09/2008
• Status: Expired due to Fees

• Current Assignee: Fuji Xerox Company Limited (Fujifilm Holdings Corporation)
• Original Assignee: Fuji Xerox Company Limited (Fujifilm Holdings Corporation)
• Inventors: Fukunaga, Masakazu
• Primary Examiner(s): Ge, Yuzhen
• Application Number:
  US12/265,214
• Publication Number:
  US 20090257658A1
• Time in Patent Office: 1,252 Days
• Field of Search: None
• US Class Current: 382/173
• CPC Class Codes: H04N 1/3873 defined only by a limited number of coordinate points or parameters, e.g. corners, centre; for trimming

Abstract

An image extracting method includes: acquiring a scan image; generating a binary image of the acquired scan image and detects connected pixels in the generated binary image; setting up a circumscribed rectangle for the detected connected pixels; performing, in each side of a circumscribed rectangle, scan in a direction perpendicular to the side so as to detect edge pixels, wherein the scan starts at a plurality of points on a line, and the line extends to one vertex of the side, from a contacting point at which the connected pixels and the side contact; determining whether the detected edge pixels are located in a contour part of the object reproduced in the scan image; setting up a rectangular region based on the edge pixels determined as being located in the contour part of the object; and extracting an image from the set-up rectangular region.

Claims

1. An image extracting apparatus comprising:

an image acquiring section that acquires a scan image obtained by scanning an object;

a detecting section that generates a binary image of the acquired scan image and detects connected pixels in the generated binary image;

a circumscribed rectangle setting section that sets up a circumscribed rectangle for the connected pixels detected by the detecting section;

an edge pixel detecting section that, in each side of the circumscribed rectangle, performs a scan in a direction perpendicular to a side of the circumscribed rectangle so as to detect edge pixels, wherein the scan starts at a plurality of points on a line, and the line extends to one vertex of the circumscribed rectangle from a contacting point at which the connected pixels and the side of the circumscribed rectangle contact;

a determining section that determines whether the edge pixels detected by the edge pixel detecting section are located in a contour part of the object reproduced in the scan image;

a rectangular region setting section that sets up a rectangular region based on the edge pixels determined as being located in the contour part of the object; and

an image extracting section that extracts an image from the rectangular region set up by the rectangular region setting section.

2. The image extracting apparatus according to claim 1,

wherein the determining section determines that, among the detected edge pixels, an edge pixel at a position exceeding a diagonal line of the circumscribed rectangle are not located in the contour part of the object.

3. The image extracting apparatus according to claim 1,

wherein the determining section determines that, among the detected edge pixels, an edge pixel whose distance to an adjacent edge pixel is greater than a threshold value is not located in the contour part of the object.

4. The image extracting apparatus according to claim 1,

wherein the determining section determines that detected edge pixels are not located in the contour part of the object when distances from the detected edge pixels to the side of the circumscribed rectangle decrease as the detected pixels approach the one vertex from the contacting point.

5. The image extracting apparatus according to claim 1,

wherein the one vertex is more distant from the contacting point among vertices of the side of the circumscribed rectangle.

6. The image extracting apparatus according to claim 1, further comprising:

a inclination calculating section that, based on position coordinates of the edge pixels as being the pixels located in the contour part of the object, calculates inclinations of at least three or more line segments constituted by the edge pixels as being the pixels located in the contour part of the object,

wherein the rectangular region setting section sets up the rectangular region based on conformity in the calculated inclinations of the line segments.

7. The image extracting apparatus according to claim 1, further comprising:

another inclination calculating section that detects an inclination between the detected connected pixels and the circumscribed rectangle,

wherein, when the detected inclination is greater than a predetermined value, processing is executed by the edge pixel detecting section, the determining section, and rectangular region setting section.

8. The image extracting apparatus according to claim 1,

wherein the object is a rectangular document image.

9. An image extracting method comprising:

acquiring a scan image obtained by scanning an object;

generating a binary image of the acquired scan image and detects connected pixels in the generated binary image;

setting up a circumscribed rectangle for the detected connected pixels;

performing, in each side of the circumscribed rectangle, a scan in a direction perpendicular to a side of the circumscribed rectangle so as to detect edge pixels, wherein the scan starts at a plurality of points on a line, and the line extends to one vertex of the circumscribed rectangle from a contacting point at which the connected pixels and the side of the circumscribed rectangle contact;

determining whether the detected edge pixels are located in a contour part of the object reproduced in the scan image;

setting up a rectangular region based on the edge pixels determined as being located in the contour part of the object; and

extracting an image from the set-up rectangular region.

10. A non-transitory computer readable medium storing a program causing a computer to execute a process for extracting images, the process comprising:

acquiring a scan image obtained by scanning an object;

generating a binary image of the acquired scan image and detects connected pixels in the generated binary image;

setting up a circumscribed rectangle for the detected connected pixels;

performing, in each side of the circumscribed rectangle, a scan in a direction perpendicular to a side of the circumscribed rectangle so as to detect edge pixels, wherein the scan starts at a plurality of points on a line, and the line extends to one vertex of the circumscribed rectangle from a contacting point at which the connected pixels and the side of the circumscribed rectangle contact;

determining whether the detected edge pixels are located in a contour part of the object reproduced in the scan image;

setting up a rectangular region based on the edge pixels determined as being located in the contour part of the object; and

extracting an image from the rectangular region set up.