CONTROL APPARATUS, IMAGE READING APPARATUS, IMAGE FORMING APPARATUS, AND RECORDING MEDIUM

• US 20100271646A1
• Filed: 04/21/2010
• Published: 10/28/2010
• Est. Priority Date: 04/23/2009
• Status: Active Grant

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Morimoto, Atsuhisa, Narikawa, Shiro
• Granted Patent: US 8,780,407 B2
• Time in Patent Office: Days
• US Class Current: 358/1.900
• CPC Class Codes: G03G 15/5025 by measuring the original characteristics, e.g. contrast, density
• CPC Class Codes: H04N 1/00681 Detecting the presence, position or size of a sheet or correcting its position before scanning H04N1/047 takes precedence; mode signalling H04N1/333; skew detection or correction in image signals H04N1/3878
• CPC Class Codes: H04N 1/00718 Skew
• CPC Class Codes: H04N 1/3873 defined only by a limited number of coordinate points or parameters, e.g. corners, centre; for trimming
• CPC Class Codes: H04N 1/3878 Skew detection or correction

Abstract

An image processing apparatus is connected to an image reading apparatus which reads a read area set on a scanner platen in accordance with a size of a document placed on the scanner platen so as to create image data in which an image of the document is shown. The image processing apparatus includes a document detection section and an instruction section. The document detection section creates, based on the image data supplied from the image reading apparatus, document area information indicative of an area where the document is placed on the scanner platen. In a case where the area indicated by the document area information is not completely encompassed by the read area, the instruction section sets a reread area which completely encompasses the area indicated by the document area information and causes the image reading apparatus to read the reread area. In a case where a document which is not completely encompassed by the read area is read, a user can carry out a rereading process more easily than a conventional art.

Claims

1. A control apparatus for controlling an image reading apparatus which creates image data of a document image by reading a read area that is set on a scanner platen in accordance with a size of a document placed on the scanner platen,

the control apparatus comprising:

a determining section which determines, based on the image data, whether or not the read area completely encompasses a necessary area which needs to be read on the scanner platen;

a setting section which sets, based on the image data, a reread area which completely encompasses the necessary area, in a case where the determining section determines that the read area does not completely encompass the necessary area; and

a rereading instruction section which causes the image reading apparatus to read the reread area that is set by the setting section.

2. The control apparatus according to claim 1, wherein

the necessary area is an area where the document is placed on the scanner platen.

3. The control apparatus according to claim 2, further comprising a document detection section which creates, based on the image data, document area information indicative of positions of respective vertexes of the document placed on the scanner platen,

the determining section determining, based on the document area information, whether the vertexes of the document are located outside or within the read area,

the setting section setting, as the reread area, an area which encompasses all of the vertexes indicated by the document area information.

4. The control apparatus according to claim 3, wherein

in a case where the document image shown in the image data has four corners, the document detection section outputs, as the document area information, coordinate values of the respective four corners, and

in a case where the document image shown in the image data has more than four corners, the document detection section (a) identifies (i) coordinate values of respective vertexes located within the read area among the vertexes of the document placed on the scanner platen, and (ii) coordinate values of respective intersections of a boundary line between the read area and an area other than the read area with sides of the document placed on the scanner platen, (b) estimates, based on the coordinate values of each of the identified vertexes and each of the identified intersections, coordinate values of respective vertexes located outside the read area among the vertexes of the document placed on the scanner platen, and (c) outputs, as the document area information, the coordinate values of the identified vertexes and the estimated vertexes.

5. The control apparatus according to claim 2, wherein

the setting section sets the reread area only in a case where the area where the document is placed is not completely encompassed by the read area, but is completely encompassed by a maximum read area which is a largest read area among available areas.

6. The control apparatus according to claim 1, wherein

the necessary area is an effective image area in the document placed on the scanner platen.

7. The control apparatus according to claim 6, wherein:

the determining section (a) creates, based on the image data, distribution information indicative of distribution of the effective image area shown by the image data, (b) identifies, based on the distribution information, one end and the other end of the effective image area in a main scanning direction, and one end and the other end of the effective image area in a sub-scanning direction, (c) determines that the read area does not completely encompass the effective image area, in a case where a shortest distance between (i) a boundary line between the read area and an area other than the read area and (ii) at least one of the ends is not more than a threshold value, and (d) determines that the read area completely encompasses the effective image area, in a case where the shortest distance between (i) the boundary line and (ii) each of the ends is more than the threshold value.

8. The control apparatus according to claim 7, wherein:

the setting section (a) identifies, based on the distribution information, (i) vertexes located within the read area among vertexes of a bounding box of the effective image area shown in the document and (ii) intersections of the boundary line with the sides of the bounding box, (b) estimates, based on coordinate values of the vertexes and intersections above identified, coordinate values of respective vertexes located outside the read area among the vertexes of the bounding box, and (c) sets, as the reread area, an area which encompasses all of the vertexes of the bounding box.

9. An image reading apparatus comprising a control apparatus recited in claim 1.

10. An image forming apparatus comprising a control apparatus according to claim 1 and the image reading apparatus.

11. A computer-readable recording medium in which a control program for causing a computer to function as each section of a control apparatus recited in claim 1 is stored.