JP2001320572A - Method and device for correcting image and recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problems that only a partial area is often inclined in one sheet of image even though a certain area is straight when an image scanner, a copying machine, etc., read the two facing pages of a bound document, a book, etc., and that much labor is needed, such as to visually confirm the image to be read, to reread the image, to separate a document, to cut off a page from a book or the like in order to acquire an image without any inclinations at the time of reading the part of two facing pages of the bound document, the book, etc., and collectively reading a plurality of sheets of cards or the like. SOLUTION: In an image correcting method, an image correcting device and a recording medium, one piece of image data is divided into margins and an information area other than the margins such as a character area and a table area, the inclination of each information area with respect to the whole image is detected and corrected to acquire an image without any inclinations.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image reading apparatus such as an image scanner, an image capturing apparatus such as a digital camera, and an image correcting method, an image correcting apparatus, and a recording medium used for image correcting processing by application software of a personal computer. In particular, by dividing one image data into a margin and other information regions such as a character region and a table region, and detecting and correcting the inclination of each information region with respect to the entire image, Get an image without tilt.

[0002]

2. Description of the Related Art When a double-page spread of a bound document or book is read by an image scanner, a copier, or the like, only a part of the image is tilted even though an area in the image is straight. Often have.

FIG. 6 is an explanatory diagram of reading of a spread portion of a book. In the figure, 61 is an image scanner, 62 is a book to be subjected to image input, 63 is a reading unit of the image scanner 61, and 64 is image data read by the reading unit 63.

[0004] In this figure, in order to read the image of the spread portion of the book, the reading was performed with the book held down evenly.
The A-side portion of the read image data 64 is read straight for the entire image, while the B-side portion is read with an inclination.

FIG. 7 is a diagram for explaining reading of a plurality of cards. In the figure, 61 is an image scanner, 71 to 7
6 is a card on which characters are written, 63 is an image scanner 6
Reference numeral 1 denotes a reading unit, reference numeral 65 denotes an original document, and reference numeral 77 denotes image data read by the reading unit 63.

In this figure, in order to read the images of the cards 71 to 76 all at once, reading was performed with the card held down by the document holder 65.
Because the parts 73 and 74 are slightly tilted, the parts of the cards 72, 73 and 74 of the read image data 77 are read while being tilted with respect to the entire image.

In the case of FIGS. 6 and 7, in order to obtain an image having no tilt, the read image is visually checked after reading, and if there is a tilt, reading is performed again. Further, if the inclination still occurs, the bound documents must be separated one by one, and the book or the like needs to be cut out and read again.

In the case of a document that cannot be disassembled, reading may be abandoned. Further, when the original to be read is a copied original, the original itself may be skewed, and image data without skew could not be obtained.

[0009]

As described above, in order to obtain an image without tilting when reading a spread portion of a conventionally bound document or book, or when reading a plurality of cards at a time, the reading must be performed. There is a problem that much trouble is required for visual confirmation of an image, rereading of an image, separation of a document, and cutting of a book. In addition, in the case of an original that cannot be disassembled or a skewed original that is a copy of the original to be read, there is a problem that reading must be abandoned.

[0010]

SUMMARY OF THE INVENTION The present invention has been made in consideration of the above problems, and has been made in consideration of an image reading apparatus such as an image scanner, an image capturing apparatus such as a digital camera, and an image processing apparatus using an application software of a personal computer. In an image correction method, an image correction apparatus, and a recording medium used for the correction processing, one image data is divided into a margin and other information areas such as a character area and a table area, and each information is stored in the entire image. By detecting and correcting the inclination of the area, an image without inclination is obtained.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (1) In a method for correcting image data of an image data read by an image input device, a bookbinding document or a spread portion of a document in which a plurality of sheets are bundled or a plurality of documents are arranged. An image reading step of reading image data to be read, a format conversion step of converting the read image data into a data format suitable for image correction processing,
An information area dividing step in which the image data whose data format has been converted in the format converting step is divided into an information area including a margin and other character areas and a table area, and an information area divided in the information area dividing step is inclined in the image data. And an image correction step of correcting an information area determined to have a tilt in the tilt determination step so that the information area does not have a tilt. Dividing into multiple information areas, detecting the inclination of each information area,
By correcting the tilt of the tilted information area, image data without tilt can be obtained.

(2) In the image correction method described in (1), the method used for dividing the information area in the image data is selected from either histogram, labeling, or both histogram and labeling.
The division of the information area can be performed by a method suitable for the image data.

(3) In the image correction method described in (1), a histogram is obtained for an image of the information area tilted by a predetermined angle within a predetermined range of the tilt angle, and the histogram distribution has the largest tilt angle. If the correction angle is set to a correction angle and the correction angle is not 0 degree, it is determined that there is a tilt, whereby the tilt of the information area can be detected and the correction angle can be quickly obtained.

(4) In the image correction method described in (1), the method for detecting the inclination of the information area is selected from histogram or labeling, thereby detecting the inclination of the information area by a method suitable for the image data. be able to.

(5) In the image correction method described in (1), the tilt correction is performed by obtaining the center point of the information area for which tilt correction is to be performed, and correcting the tilt of the information area by rotating about the center point. The tilt correction can be performed without destroying the information area other than the information area.

(6) In the image correction method described in (5), when the inclination of the information area is corrected, the gap generated by the correction is filled with the color of the blank area, so that the inclination correction can be performed without discomfort to the entire image. It can be carried out.

(7) The image data to be subjected to the image correction in the image correction method of the image data read by the image input device for the spread portion of the bookbinding document or the document in which a plurality of sheets are bundled, or the document in which a plurality of documents are arranged. Image reading means to be read, format conversion means for converting the read image data into a data format suitable for image correction processing, and image data whose data format has been converted by the format conversion means into margins and other character areas and table areas. Information area dividing means for dividing the information area into information areas, inclination determining means for determining whether the information area divided by the information area dividing means has an inclination in image data, and image correction for correcting the information area so as not to be inclined Means, the inclination of the information area in the read image data can be corrected, and an image without inclination can be obtained.

(8) In the image correction device described in (7), information is provided by selecting a method used for dividing an information area in the image data from either histogram, labeling, or both histogram and labeling. The division of the area can be performed by a method suitable for the image data.

(9) In the image correction device described in (7), a histogram is obtained for an image of the information area tilted by a predetermined angle within a predetermined range of the tilt angle, and the histogram distribution has the largest tilt angle. By providing a correction angle and a means for determining that there is a tilt when the correction angle is not 0 degree, the tilt detection of the information area and the correction angle can be quickly obtained.

(10) In the image correction apparatus described in (7), by providing means for selecting the method used for detecting the inclination of the information area from histogram or labeling, the inclination detection of the information area is suitable for the image data. Can be done in a way.

(11) In the image correction apparatus described in (7), the means for determining the center point of the information area for which the inclination is to be corrected and rotating the center of the information area to correct the inclination of the information area is provided. Tilt correction can be performed without destroying information areas other than the information area to be corrected.

(12) In the image correction apparatus described in (11), when the inclination of the information area is corrected, a means for filling the gap generated by the correction with the color of the blank area is provided, thereby performing the inclination correction on the entire image. Can be performed without discomfort.

(13) The target of image correction on a recording medium in which a program for correcting image data read by an image input device is recorded on a spread portion of a bookbinding document or a document in which a plurality of sheets of paper are bundled or a plurality of documents are arranged. An image reading step for reading image data to be read, a format conversion step for converting the read image data into a data format suitable for image correction processing, and a margin and other characters for the image data whose data format has been converted in the format conversion step. An information area dividing step of dividing into information areas including an area and a table area; a slope determining step of determining whether the information area divided in the information area dividing step has a slope in the image data; and a slope determining step of the information area. And a program for executing an image correction step of correcting the information area determined to have no tilt. By executing the body with computer to correct the inclination of the information area in the read image data, it is possible to obtain the tilt-free image.

[0024]

FIG. 1 is a block diagram showing the configuration of an image correction apparatus according to the present invention. In the figure, reference numeral 10 denotes an image correction device for correcting image data obtained by reading a spread portion of a bookbinding document or a document in which a plurality of sheets of paper are bundled or a plurality of documents arranged, such as an image input device.

The image correction device 10 includes an image reading means 1 for reading image data to be subjected to image correction, and a format conversion means 2 for converting the image data read by the image reading means 1 into a data format suitable for image correction processing. An information area dividing means 3 for dividing the image data which has been subjected to the data format conversion by the format converting means 2 into information areas including margins and other character areas and table areas; It is composed of a tilt determining means 4 for determining whether there is a tilt in the data, and an image correcting means 5 for correcting the information area determined to have a tilt by the tilt determining means 4 so as not to have a tilt.

The image correction method will be described with reference to FIGS. FIG. 2 is a processing flowchart of an embodiment of the image correction method of the present invention, FIG. 3 is an explanatory diagram (1) of the image correction, FIG. 4 is an explanatory diagram (2) of the image correction, and FIG. 3).

Hereinafter, the processing will be described according to the flow of FIG. In this example, image data obtained by reading a white card in which black characters are written horizontally is set as a correction target.

Step S201: Image data read by an image scanner or the like is read. In this example, image data as shown in FIG. 4A is read by collectively reading cards 1 to 6 on which characters are written horizontally. In the read image data, the cards 2, 3, and 4 are inclined with respect to the entire image.

Step S202: The image data is displayed on the display, and information such as a method used for dividing the information area and a method used for detecting the inclination is obtained from the operator. In this example, an image correction screen is displayed on the display as shown in FIG. 3 to display a read image, select a method of dividing the information area, select a method of detecting inclination, and determine an information area used when detecting inclination using a histogram. The tilt angle range and the tilt accuracy can be set.

Step S203: The image data is divided into information areas such as a margin, a character area, and a table area by the method used for dividing the information area designated in step 202, and the divided information areas are numbered. FIG. 4B shows the image data of FIG. 4A divided into a margin and an information area.
It is. The information areas 2, 3, and 4 corresponding to the cards 2, 3, and 4 in which the inclination occurs are larger than the information areas 1, 5, and 6 corresponding to the cards 1, 5, and 6, respectively. I have.

Step S204: The image data is converted into binary data which can be easily corrected.

Step S205: The counter C is set to 0.

Step S206: It is determined whether the counter C is equal to the number of information areas. If they are the same, the process ends; otherwise, the process proceeds to step S207.

Step S207: A histogram is obtained by tilting the information area of the number of the counter C within the range of the tilt angle specified in step S202 and for each tilt accuracy, and the tilt angle having the largest histogram distribution is set as the correction angle. calculate. In this example, as shown in FIG. 4B, the tilt angle of the information area 2 is −θ, and the horizontal direction is 0 degree.
Since it is detected that the information area 3 has an inclination of + θ and the information area 4 has an inclination of + θ, the information area 2 is set to a correction angle of + θ.
θ, the information area 3 is −θ, and the information area 4 is −θ.

Step S208: It is determined whether the correction angle detected in step S207 is 0 degree. If it is 0 degree, the process proceeds to step S211. If it is not 0 degree, step S20.
Go to 9.

Step S209: The center point of the information area is obtained, and the inclination correction for the correction angle is performed with the center point as an axis. In FIG. 4 (b), the information areas 2, 3, which have a tilt,
FIG. 4C shows the image data in which the inclination of FIG. 4 has been corrected.

Step S210: The color of the margin is obtained, and the gap generated when the inclination is corrected is filled with the color of the margin.
The shaded portion in FIG. 5D is a gap portion generated when the inclination correction of the correction angle: −θ is performed with the center point a of the information area 4 as an axis.

Step S211: One counter C is updated. Then, the process returns to step S206.

In this example, since the image data was corrected for black and white image data, the data format of the image data was converted to binary data in step S204. The format (binary data, grayscale data, 16-bit color data, 24-bit color data, etc.) may be obtained.

[0040]

The present invention is embodied in the form described above, and has the following effects.

One image data is divided into a margin and a plurality of other information areas, the inclination of each information area is detected, and only the information area where the inclination is detected is corrected so as not to have an inclination. This makes it possible to acquire an image without inclination as one image.

This eliminates the need to read the image again, thereby reducing the time required for reading. Further, even when the original to be read is already inclined, an image without inclination can be captured.
Therefore, the target range of the original to be read can be expanded.

Further, by correcting the inclination of the information area, the recognition rate can be improved when character recognition is performed thereafter. Further, since the inclination of the image can be automatically corrected, it is possible to automate processing after reading.

[Brief description of the drawings]

FIG. 1 is a configuration block diagram of an image correction device according to the present invention.

FIG. 2 is a processing flowchart of an embodiment of an image correction method according to the present invention.

FIG. 3 is an explanatory diagram (1) of image correction.

FIG. 4 is an explanatory diagram (2) of image correction.

FIG. 5 is an explanatory diagram (3) of image correction.

FIG. 6 is an explanatory diagram of reading a double-page spread of a book.

FIG. 7 is an explanatory diagram of reading a plurality of cards.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Image reading means 2 Format conversion means 3 Information area division means 4 Inclination determination means 5 Image correction means 10 Image correction device

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G06T 7/00 200 G06T 7/00 200B 7/60 150 7/60 150C 150P F-term (Reference) 5B057 AA11 CA02 CA08 CA12 CA16 CB02 CB08 CB12 CB16 CC01 CD03 CE09 CE12 DB02 DB05 DB09 DC02 DC08 DC23 5C076 AA24 AA37 AA40 BA06 5L096 AA03 AA06 BA07 DA01 EA35 EA43 FA37 FA42 FA62 FA67 GA34 MA03

Claims (13)

[Claims] 1. A method for correcting image data read by an image input device for a bookbinding document or a spread portion of a document in which a plurality of sheets of paper are bundled or a plurality of arranged documents is read. An image reading step, a format conversion step of converting the read image data into a data format suitable for image correction processing, and the image data whose data format has been converted in the format conversion step includes a margin and other character areas and table areas An information area dividing step for dividing into information areas, a tilt determining step for determining whether the information area partitioned in the information area separating step has a tilt in the image data, and an information area determined to have a tilt in the tilt determining step And an image correcting step of correcting the image data so that there is no inclination. One image data is divided into a margin and a plurality of other information areas. An image correction method, comprising detecting a tilt of an area and correcting a tilt of an information area having a tilt. 2. The image correction method according to claim 1, wherein
An image correction method characterized in that a method used for dividing an information area in image data is selected from either histogram, labeling, or both histogram and labeling. 3. The image correction method according to claim 1, wherein
In the range of the predetermined tilt angle, a histogram is taken for the image of the information area tilted by a predetermined angle, the tilt angle having the largest histogram distribution is set as the correction angle, and when the correction angle is not 0 degree, there is a tilt. An image correction method characterized by determining. 4. The image correction method according to claim 1, wherein
An image correction method, wherein a method used for detecting a tilt of an information area is selected from histogram or labeling. 5. The image correction method according to claim 1, wherein
An image correction method comprising: obtaining a center point of an information area for which tilt correction is to be performed; and rotating the information area around the center point to correct the tilt of the information area. 6. The image correction method according to claim 5, wherein
An image correction method characterized in that when a tilt of an information area is corrected, a gap generated by the correction is filled with a color of a blank area. 7. An image correction apparatus for reading image data of a bookbinding original or a spread of originals in which a plurality of sheets of paper are bundled, or an original in which a plurality of originals are arranged, is read by an image input device. Image reading means (1), format conversion means (2) for converting image data read by the image reading means into a data format suitable for image correction processing, and converting the image data converted by the format conversion means into margins. An information area dividing means (3) for dividing into other information areas including a character area and a table area; and an inclination determining means (4) for judging whether or not the information area divided by the information area dividing means has an inclination in the image data. )
And an image correcting means (5) for correcting the information area so as not to be tilted. 8. The image correction apparatus according to claim 7, wherein
An image correction apparatus, comprising: means for selecting a method used for dividing an information region in image data from either histogram, labeling, or both histogram and labeling. 9. The image correction apparatus according to claim 7, wherein
In the range of the predetermined tilt angle, a histogram is taken for the image of the information area tilted by a predetermined angle, the tilt angle having the largest histogram distribution is set as the correction angle, and when the correction angle is not 0 degree, there is a tilt. An image correction apparatus, comprising: a determination unit. 10. The image correction apparatus according to claim 7, further comprising means for selecting a method used for detecting the inclination of the information area from histogram or labeling. 11. The image correction apparatus according to claim 7, further comprising: means for obtaining a center point of the information area for which inclination correction is to be performed, and rotating about the center point to correct the inclination of the information area. Image correction device. 12. The image correction apparatus according to claim 11, further comprising means for, when the inclination of the information area is corrected, filling a gap generated by the correction with a color of a blank area. 13. A recording medium storing a program for correcting image data read by an image input device on a spread portion of a bound document or a document in which a plurality of sheets of paper are bundled, or a plurality of arranged documents. An image reading step for reading image data to be read, a format conversion step for converting the read image data into a data format suitable for image correction processing, and a margin and other character areas for converting the image data converted in the format conversion step into a margin. An information area dividing step of dividing the image area into information areas including a table area and a table area; an inclination determining step of determining whether the information area divided in the information area dividing step has an inclination in the image data; An image correction step of correcting the determined information area so as to have no inclination. Data readable recording medium.