Image reading apparatus and image forming apparatus, comprising at least a mode reception and a selection of at least a quality first mode or a speed first mode

Patent metadata

Field	Value
Publication number	US-10321014-B2
Application number	US-201615754441-A
Country	US
Kind code	B2
Filing date	Aug 25, 2016
Priority date	Sep 29, 2015
Publication date	Jun 11, 2019
Grant date	Jun 11, 2019

Abstract

An image reading unit reads a source document image in 600 dpi, and a resolution conversion unit converts the resolution of the image to 75 dpi. An inclination detection unit detects inclination of the source document image. When a character conversion unit is to execute character recognition after cropping, a mode setting unit sets a quality-first mode. The inclination correction unit corrects the inclination of the image of 600 dpi, according to the inclination of the source document image detected by the inclination detection unit. A document image clipping unit clips out the source document image, and the resolution conversion unit converts the resolution of the source document image to 200 dpi. Thereafter, the character conversion unit executes the character recognition.

First claim

What is claimed is:

1. An image reading apparatus comprising:
a document table on which a source document is to be placed;
an image reading unit that reads the source document placed on the document table in a predetermined resolution and acquires an image;
a first resolution conversion unit that converts the resolution of the image acquired by the image reading unit into a first resolution for inclination detection lower than the predetermined resolution;
an inclination detection unit that detects the inclination of an image of the source document contained in the image subjected to the resolution conversion by the first resolution conversion unit;
an inclination correction unit that corrects the inclination of the image according to the inclination detected by the inclination detection unit;
a document image clipping unit that clips out the image of the source document from the image;
a second resolution conversion unit that converts the resolution of the image into a second resolution for generating a read image lower than the predetermined resolution and higher than the first resolution; and
a mode setting unit that sets a quality-first mode or a speed-first mode,
wherein, when the mode setting unit sets the quality-first mode, the document image clipping unit clips out, after the inclination correction unit corrects the inclination of the image acquired by the image reading unit in the predetermined resolution, according to the inclination detected by the inclination detection unit, the image of the source document from the image subjected to the inclination correction, and the second resolution conversion unit converts the resolution of the image of the source document into the second resolution, and
when the mode setting unit sets the speed-first mode, the second resolution conversion unit converts, after the document image clipping unit clips out the image of the source document from the image acquired by the image reading unit in the predetermined resolution, the resolution of the image of the source document that has been clipped out into the second resolution, and the inclination correction unit corrects the inclination of the image of the source document subjected to the resolution conversion into the second resolution, according to the inclination detected by the inclination detection unit.

2. The image reading apparatus according to claim 1 , further comprising:
a document size detection unit that detects a size of the source document from the image subjected to resolution conversion by the first resolution conversion unit; and
a document position detection unit that detects a position of the source document, from the image subjected to the resolution conversion by the first resolution conversion unit.

3. The image reading apparatus according to claim 2 ,
wherein the mode setting unit sets the speed-first mode when the image read by the image reading unit is equal to or larger than a predetermined size, and the mode setting unit sets the quality-first mode when the image read by the image reading unit is smaller than the predetermined size.

4. The image reading apparatus according to claim 1 , further comprising a character conversion unit that recognizes a character contained in the image and converts the character into character data,
wherein, when the character conversion unit is to convert the character contained in the source document image into the character data, the mode setting unit sets the quality-first mode.

5. The image reading apparatus according to claim 1 , further comprising a character size detection unit that detects a size of a character contained in the source document image,
wherein the mode setting unit sets the speed-first mode when the character contained in the source document image is equal to or larger than a predetermined size, and the mode setting unit sets the quality-first mode when the character contained in the source document image is smaller than the predetermined size.

6. The image reading apparatus according to claim 1 , further comprising a mode reception unit through which a selection of the quality-first mode or the speed-first mode is inputted by a user,
wherein the mode setting unit sets either mode according to the input received through the mode reception unit.

7. The image reading apparatus according to claim 1 , further comprising an edge alignment decision unit that analyzes the image acquired by the image reading unit and decides whether the source document is located along an edge of a reading range, when the image reading unit is to read the source document,
wherein the edge alignment decision unit (i) detects edge points in the image, and detects a succession of a predetermined number or more of the detected edge points as a first edge line; (ii) extracts, from the first edge line, a second edge line perpendicular or horizontal in the image of a rectangular shape; (iii) selects a third edge line closest to each of four sides defining the image of the rectangular shape, from the second edge line; (iv) decides, when one of the third edge lines intersects another of the third edge line, and the one intersecting edge line is defined as a crossing edge line, whether the another edge line protrudes from the crossing edge line toward a side defining the image closest to the crossing edge line; (v) decides that the source document is located along an edge of the reading range, when there is one crossing edge line from which the another edge line protrudes toward the side defining the image, or when there are two crossing edge lines from which the another edge line protrudes toward the side defining the image, and the two edge lines are orthogonal to each other; and (vi) decides that the source document is not located along an edge of the reading range, when there is no crossing edge line from which the another edge line protrudes toward the side defining the image, or when there are two crossing edge lines from which the another edge line protrudes toward the side defining the image, but the two edge lines are not orthogonal to each other, and
the document image clipping unit (i) determines, when the edge alignment decision unit decides that the source document is located along an edge of the reading range, a region surrounded by the third edge line other than the crossing edge line and the side defining the image data closest to the crossing edge line, as a region to be clipped out from the image; and (ii) determines, when the edge alignment decision unit decides that the source document is not located along an edge of the reading range, a region surrounded by the first edge line closer than the third edge line to a side defining the image closest to the third edge line, as the region to be clipped out.

8. The image reading apparatus according to claim 7 ,
wherein the edge alignment decision unit extracts the first edge line deviated from the line perpendicular or horizontal in the image of the rectangular shape, within a predetermined angle.

9. The image reading apparatus according to claim 1 , further comprising a document guide located along a side of the document table,
wherein the document image clipping unit determines a region to be clipped out from the image of the source document, on a basis of the image obtained through the reading of the image reading unit, by detecting an edge of the source document, according to an image representing a shadow that appears around the source document and an image representing halation that takes place around the source document, detecting a length of a side of the source document in a region where the image representing the shadow and the image representing the halation are absent, on a basis of a length of an image indic

Assignees

• Kyocera Document Solutions Inc

Inventors

• Tagami Yuya
• Harada Hiroyuki

Classifications

• H04N1/3935 Primary

  with modification of image resolution, i.e. determining the values of picture elements at new relative positions · CPC title

• H04N1/00469

  with enlargement of a selected area of the displayed information · CPC title

• H04N1/00779

  Adjusting settings, e.g. mode, feeding rate or type of paper · CPC title

• G06T1/00

  General purpose image data processing · CPC title

• G06T3/60

  Rotation of whole images or parts thereof · CPC title