Image forming apparatus, scanned image correction method thereof, and non-transitory computer-readable recording medium

Patent metadata

Field	Value
Publication number	US-11295415-B2
Application number	US-201716325948-A
Country	US
Kind code	B2
Filing date	Jun 16, 2017
Priority date	Aug 17, 2016
Publication date	Apr 5, 2022
Grant date	Apr 5, 2022

Abstract

An image forming apparatus, a scanned image correction method of an image forming apparatus, and a non-transitory computer-readable recording medium are provided. The image forming apparatus includes a scan unit to scan a document to generate a scanned image and a processor to detect a skew angle of the scanned image, determine a reference point on the basis of a position of a content in the scanned image, and rotate the scanned image around the determined reference point to correct the skew angle.

First claim

The invention claimed is:

1. An image forming apparatus comprising:
a scan unit to scan a document to generate a scanned image; and
a processor to,
detect a skew angle of the scanned image,
determine, as a reference point, a central coordinate position of a content detected, among a plurality of contents detected, included in the scanned image, based on,
detecting the plurality of contents, and deciding sizes and central coordinate positions of respective contents of the plurality of contents,
assigning weights to the central coordinate positions of the respective contents depending on the sizes of the respective contents, and
determining the reference point on a basis of the weighted central coordinate positions of the respective contents; and

use the reference point as a center point of a rotation to rotate the scanned image around the reference point to correct the detected skew angle.

2. The image forming apparatus as claimed in claim 1 , wherein the processor detects a boundary of the document from the scanned image and detects the skew angle of the scanned image on a basis of the boundary.

3. The image forming apparatus as claimed in claim 2 , wherein the processor detects the content, and detects the skew angle of the scanned image on a basis of a gradient of the content when the boundary of the document is not detected.

4. The image forming apparatus as claimed in claim 3 , wherein the processor detects the gradient of the content using at least one of a gradient of a character string, a gradient of a line of a chart, or a gradient of a video edge which is included in the scanned image.

5. The image forming apparatus as claimed in claim 1 , further comprising an input/output unit to display a screen and receive a user input,
wherein the processor controls the input/output unit to display a user interface through which one of a plurality of methods of detecting the skew angle of the scanned image is selected, and detects the skew angle of the scanned image by the selected method according to a user input selecting one of the plurality of methods.

6. The image forming apparatus as claimed in claim 5 , wherein the plurality of methods includes a first method of detecting the skew angle by detecting a boundary of the document, a second method of detecting the skew angle by detecting the content in the scanned image, and a third method of performing the second method when the skew angle is not detected by the first method.

7. The image forming apparatus as claimed in claim 1 , wherein the processor detects a plurality of text regions as the content detected in the scanned image, and decides a page orientation of the scanned image on a basis of string orientations of each of the plurality of text regions.

8. The image forming apparatus as claimed in claim 7 , wherein the processor detects a text region, among the text regions, having a predetermined text size.

9. The image forming apparatus as claimed in claim 7 , wherein the processor detects an amount of required rotation from the string orientations of the text regions, and rotates the scanned image in the page orientation of the scanned image when the amount of the required rotation is larger than a predetermined value.

10. A scanned image correction method of an image forming apparatus, comprising:
generating a scanned image by scanning a document;
detecting a skew angle of the scanned image;
determining, as a reference point, a central coordinate position of a content detected, among a plurality of contents detected, included in the scanned image, based on,
detecting the plurality of contents, and deciding sizes and central coordinate positions of respective contents of the plurality of contents,
assigning weights to the central coordinate positions of the respective contents depending on the sizes of the respective contents, and
determining the reference point on a basis of the weighted central coordinate positions of the respective contents; and

rotating the scanned image around the reference point to correct the skew angle, using the reference point as a center point of the rotating to correct the detected skew angle.

11. The scanned image correction method as claimed in claim 10 , wherein the detecting of the skew angle includes:
detecting a boundary of the document from the scanned image; and
detecting the skew angle of the scanned image on a basis of the boundary.

12. The scanned image correction method as claimed in claim 11 , wherein the detecting of the skew angle is on a basis of a gradient of the detected content when the boundary of the document is not detected.

13. The scanned image correction method as claimed in claim 12 , wherein in the detecting of the skew angle, the gradient of the content is detected using at least one of a gradient of a character string, a gradient of a line of a chart, or a gradient of a video edge which is included in the scanned image.

14. The scanned image correction method as claimed in claim 10 , further comprising displaying a user interface through which one of a plurality of methods of detecting the skew angle of the scanned image is selected,
wherein in the detecting of the skew angle, the skew angle of the scanned image is detected by a method selected according to a user input selecting one of the plurality of methods.

Assignees

• Hp Printing Korea Co Ltd
• Hewlett Packard Development Co

Inventors

• Lee Hae-Kee
• Gong Jung-Tag
• Lee Chang-Hyung
• Lee Ho-Keun

Classifications

• G06T3/60 Primary

  Rotation of whole images or parts thereof · CPC title

• G06V30/153

  using recognition of characters or words · CPC title

• G06V30/1475

  Inclination or skew detection or correction of characters or of image to be recognised · CPC title

• G06V30/1463 Primary

  Orientation detection or correction, e.g. rotation of multiples of 90 degrees · CPC title

• G06V30/10

  Character recognition · CPC title