JP2011250251A - Image processing system, additional image compositing method, and additional image compositing program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image processing system, an additional image compositing method, and an additional image compositing program which facilitate the operation to composite additional images to each of the background regions of multiple original images.SOLUTION: A MFP comprises: an original image acquisition part 51 which acquires multiple pages of original images; a background region detection part 53 which detects each of the background regions of the multiple original images; a common background region extraction part 55 which extracts a common background region shared by the multiple original images; an additional image acquisition part 93 which acquires additional images; a background region candidate determination part 57 which determines one or more candidate positions to add the acquired additional images to the common background region; a candidate position display part 65 which displays one or more the determined candidate positions; a selection part 91 which selects one of the one or more candidate positions; a composition part 95 which composites the additional images to the selected candidate positions of each of the multiple original images.

Description

  The present invention relates to an image processing apparatus, an additional image composition method, and an additional image composition program, and more particularly to an image processing apparatus for adding the same image to the same position of a plurality of pages of a document image and an additional image executed by the image processing apparatus. The present invention relates to a composition method and an additional image composition program.

  There is a demand for a technique for adding the same image to the same position on every page of a multi-page document. For example, in Japanese Patent Application Laid-Open No. 2007-212282, for all pages of a document composed of a plurality of pages, detection means for detecting a margin area in the page and a designated additional image are added to all pages of the document with the same size. Determining means for determining the image size of the additional image based on the detection result of the detecting means, and combining means for combining the additional image with each page of the document with the image size determined by the determining means. An image processing apparatus having the above-described features is described.

However, the conventional image processing apparatus can add the additional image to all pages of the document with the same size, but the image size of the additional image varies depending on the blank area in the page for all pages of the document including a plurality of pages. To do. For this reason, there is a problem that the image size of the additional image cannot be synthesized with a predetermined size.
JP 2007-212282 A

  The present invention has been made to solve the above-described problems, and one of the objects of the present invention is to provide an additional image synthesizer and an additional image synthesizer that facilitates the operation of synthesizing the additional image with the background area of each of the plurality of document images. An image synthesis method and an additional image synthesis program are provided.

  Another object of the present invention is to provide an additional image synthesizing apparatus, an additional image synthesizing method, and an additional image synthesizing program that facilitate the operation of synthesizing the additional image with the low density areas of the plurality of document images.

  Still another object of the present invention is to provide an additional image synthesizing apparatus, an additional image synthesizing method, and an additional image synthesizing program, which facilitate the operation of synthesizing the additional image with the high density area of each of the plurality of document images.

  The present invention has been made to solve the above-described problem. According to one aspect of the present invention, an image processing apparatus includes a document image acquisition unit that acquires a plurality of pages of document images, and a plurality of document images. Detection means for detecting a background area, extraction means for extracting a common background area common to a plurality of document images, additional image acquisition means for acquiring an additional image, and addition of the acquired additional image in the common background area Base area candidate determining means for determining one or more candidate positions for performing, candidate position displaying means for displaying the determined one or more candidate positions, and selecting means for selecting one of the one or more candidate positions And combining means for combining the additional image with the selected candidate position of each of the plurality of document images.

  According to this aspect, a background area of each of a plurality of document images is detected, a common background area common to the plurality of document images is extracted, and one or more candidate positions for adding an additional image in the common background area are detected. Determined and displayed. Then, an additional image is combined with each of the plurality of document images at a candidate position selected from one or more candidate positions. For this reason, the same additional image is synthesized at the same position of a plurality of document images. Since the position where the additional image is combined is selected from one or more candidate positions determined from the common background area common to the plurality of document images, the additional image is added to the background area of each of the plurality of document images. It is possible to provide an image processing apparatus that facilitates the combining operation.

  Preferably, the common background area is expanded by moving or reducing any one non-background area of the plurality of document images and non-background area extraction means for extracting an area other than the background area from each of the plurality of document images. And a common background region enlargement unit, and the first candidate position determination unit determines one or more candidate positions in the common background region after being enlarged.

  According to another aspect of the present invention, an image processing apparatus includes a document image acquisition unit that acquires a plurality of pages of document images, and a logical OR high density in which the image density is equal to or higher than a predetermined value in one or more of the plurality of document images. A logical OR high density area extracting unit for extracting an area, an additional image acquiring unit for acquiring an additional image, and an acquired additional image in a low density area other than the extracted logical OR high density area Low density region candidate determining means for determining one or more candidate positions; candidate position displaying means for displaying the determined one or more candidate positions; and selecting means for selecting one of the one or more candidate positions; Synthesizing means for synthesizing the additional image at the selected candidate position of each of the plurality of document images.

  According to this aspect, a logical OR high density region in which the image density is a predetermined value or more is extracted from one or more of a plurality of document images, and the acquired additional image is acquired in a low density region other than the logical OR high density region. One or more candidate positions for adding are determined and displayed. Then, an additional image is combined with each of the plurality of document images at a candidate position selected from one or more candidate positions. For this reason, the same additional image is synthesized at the same position of a plurality of document images. The position where the additional image is combined is selected from one or more candidate positions determined from the low-density areas where the image density is lower than a predetermined value in any of the plurality of document images. It is possible to provide an image processing apparatus that facilitates an operation of combining an additional image with a low density region of each image.

  Preferably, the image processing apparatus further includes background order assigning means for assigning a higher priority to one or more candidate positions as the number of document images in which the candidate area is a background area among a plurality of document images increases.

  According to this aspect, the user can select candidate positions so that the number of document images in which the position where the additional image is combined becomes a background area is as large as possible.

  Preferably, a character area detecting unit that detects a character region from each of a plurality of document images, a logical character region extracting unit that extracts a logical character region extracted as a character region in one or more of the plurality of document images, The density area candidate determining means determines the candidate position in the non-character area other than the logical sum character area in the low density area.

  According to this aspect, it is possible to synthesize an additional image at a position that is not a character area in any of a plurality of document images.

  Preferably, the apparatus further comprises a non-character area enlarging means for enlarging the non-character area by moving or reducing any one character area of the plurality of document images, and the low-density area candidate determining means is enlarged. One or more candidate positions are determined in the subsequent non-character region.

  According to still another aspect of the present invention, an image processing apparatus includes a document image acquisition unit that acquires a plurality of pages of a document image, and a logical sum that is equal to or higher than a predetermined value in one or more of the plurality of document images. One or more candidate positions for adding the acquired additional image in the extracted high density area, a logical OR high density area extracting means for extracting the density area, an additional image acquiring means for acquiring the additional image, and High density region candidate determining means for determining, candidate position displaying means for displaying one or more determined candidate positions, selecting means for selecting one of the one or more candidate positions, and each of a plurality of document images Combining means for combining the additional image with the selected candidate position.

  According to this aspect, one or more candidate positions for adding an additional image in the high density area are extracted from one or more of the plurality of document images. Is determined and displayed. Then, an additional image is combined with each of the plurality of document images at a candidate position selected from one or more candidate positions. For this reason, the same additional image is synthesized at the same position of a plurality of document images. Since the position where the additional image is combined is selected from one or more candidate positions determined from one or more of the plurality of document images and a logical high-density region having a density equal to or higher than a predetermined value, It is possible to provide an image processing apparatus that facilitates an operation of combining an additional image with a high density area of each original image.

  Preferably, the apparatus further includes a high density ranking assigning unit that gives higher priority to one or more candidate positions as the number of document images in which the candidate area is a high density area among a plurality of document images increases.

  According to this aspect, the user can select candidate positions so that the number of document images in which the position where the additional image is combined becomes a high density area is as large as possible.

  Preferably, a character region extracting unit that extracts a character region from each of a plurality of document images, a logical character region extracting unit that extracts a logical character region to be a character region extracted from one or more of the plurality of document images, The high density area candidate determining means determines the candidate position within the extracted high density area and in a non-character area other than the logical sum character area.

  According to this aspect, it is possible to synthesize an additional image at a position that is not a character area in any of a plurality of document images.

  Preferably, the apparatus further comprises a non-character area enlarging means for enlarging the non-character area by moving or reducing any one character area of the plurality of document images, and the high-density area candidate determining means is enlarged. One or more candidate positions are determined in the subsequent non-character region.

  Preferably, the image processing apparatus further includes an edge rank order assigning unit that assigns a higher priority to the determined one or more candidate positions closer to the edge of the document.

  According to this aspect, the additional image can be synthesized at a position close to the edges of the plurality of document images.

  According to still another aspect of the present invention, the additional image composition method includes a step of acquiring a plurality of document images, a step of detecting a background area of each of the plurality of document images, and a common common to the plurality of document images. A step of extracting a background area; a step of acquiring an additional image; a step of determining one or more candidate positions for adding the acquired additional image within the common background area; and the determined one or more candidates A step of displaying a position, a step of selecting one of the one or more candidate positions, and a step of synthesizing the additional image with the selected candidate position of each of the plurality of document images.

  According to this aspect, it is possible to provide an additional image synthesis method that facilitates an operation of synthesizing the additional image with the background area of each of the plurality of document images.

  According to still another aspect of the present invention, an additional image composition method includes a step of acquiring a plurality of document images, and a logical OR high-density region in which the image density is equal to or higher than a predetermined value in one or more of the plurality of document images. Extracting an additional image; determining one or more candidate positions for adding the acquired additional image in a low density region other than the extracted logical OR high density region; Displaying the determined one or more candidate positions; selecting one of the one or more candidate positions; and synthesizing the additional image at the selected candidate position of each of the plurality of document images; ,including.

  According to the present invention, it is possible to provide an additional image synthesis method that facilitates an operation of synthesizing an additional image with low density regions of a plurality of document images.

  According to still another aspect of the present invention, an additional image composition method includes a step of acquiring a plurality of document images, and a logical OR high-density region in which the image density is equal to or higher than a predetermined value in one or more of the plurality of document images. , Extracting an additional image, determining one or more candidate positions for adding the acquired additional image within the extracted high-density region, and determining one or more determined A step of displaying a candidate position; a step of selecting one of the one or more candidate positions; and a step of synthesizing the additional image with the selected candidate position of each of the plurality of document images.

  According to the present invention, it is possible to provide an additional image synthesis method that facilitates an operation of synthesizing an additional image with a high density area of each of a plurality of document images.

  According to still another aspect of the present invention, the additional image composition program includes a step of acquiring a plurality of document images, a step of detecting a background area of each of the plurality of document images, and a common common to the plurality of document images. A step of extracting a background area; a step of acquiring an additional image; a step of determining one or more candidate positions for adding the acquired additional image within the common background area; and the determined one or more candidates Causing the computer to execute a step of displaying the position, a step of selecting one of the one or more candidate positions, and a step of combining the additional image with the selected candidate position of each of the plurality of document images.

  According to this aspect, it is possible to provide an additional image synthesis program that facilitates an operation of synthesizing an additional image with a background area of each of a plurality of document images.

  According to still another aspect of the present invention, the additional image composition program includes a step of acquiring a plurality of document images, and a logical high density region in which the image density is a predetermined value or more in one or more of the plurality of document images. Extracting an additional image; determining one or more candidate positions for adding the acquired additional image in a low density region other than the extracted logical OR high density region; Displaying the determined one or more candidate positions; selecting one of the one or more candidate positions; and synthesizing the additional image at the selected candidate position of each of the plurality of document images; , Execute on the computer.

  According to the present invention, it is possible to provide an additional image synthesis program that facilitates an operation of synthesizing an additional image in a low density area of each of a plurality of document images.

  According to still another aspect of the present invention, the additional image composition program includes a step of acquiring a plurality of document images, and a logical high density region in which the image density is a predetermined value or more in one or more of the plurality of document images. , Extracting an additional image, determining one or more candidate positions for adding the acquired additional image within the extracted high-density region, and determining one or more determined The computer is caused to execute a step of displaying candidate positions, a step of selecting one of one or more candidate positions, and a step of combining an additional image with each selected candidate position of a plurality of document images.

  According to the present invention, it is possible to provide an additional image synthesis program that facilitates an operation of synthesizing an additional image with a high density area of each of a plurality of document images.

1 is a perspective view showing an appearance of an MFP. 2 is a block diagram illustrating an example of a hardware configuration of an MFP. FIG. It is a top view which shows an example of an operation panel. 2 is a block diagram illustrating an overview of functions of a CPU provided in the MFP. FIG. (A) is a diagram showing an example of an additional image setting screen, (B) is a diagram showing an example of a background region setting screen, and (C) is a diagram showing an example of a density region setting screen. (A) is a figure which shows an example of the original image of the 1st page, (B) is a figure which shows an example of the original image of the 2nd page. It is a figure which shows an example of a common base area | region. (A) is a view showing an example of a document image after moving an image included in the document image of the second page, and (B) is a view of the document image shown in FIG. 6 (A) and FIG. 8 (A). It is a figure which shows an example of the common base area | region extracted from the document image of the 2nd page after the change shown. (A) is a view showing an example of an original image after reducing an image included in the original image of the second page, and (B) is an original image shown in FIG. 6 (A) and FIG. 9 (A). It is a figure which shows an example of the common base area | region extracted from the document image of the 2nd page after the change shown. (A) is a first diagram illustrating an example of a selection screen, (B) is a diagram illustrating an example of a document image of a first page, and (C) is a diagram illustrating an example of a document image of a second page. It is. It is a 2nd figure which shows an example of a selection screen. It is a 3rd figure which shows an example of a selection screen. It is a flowchart which shows an example of the flow of an additional image composition process. It is a flowchart which shows an example of the flow of a background area | region candidate determination process. It is a flowchart which shows an example of the flow of a low concentration area | region candidate determination process. It is a flowchart which shows an example of the flow of a high concentration area | region candidate determination process.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same parts are denoted by the same reference numerals. Their names and functions are also the same. Therefore, detailed description thereof will not be repeated.

  FIG. 1 is a perspective view showing the appearance of the MFP. Referring to FIG. 1, MFP 100 includes an operation panel 9, an automatic document feeder (ADF) 10, a document reading unit 20, an image forming unit 30, and a paper feeding unit 40.

  The ADF 10 automatically conveys a plurality of documents set on the document feeding tray 11 one by one to a predetermined document reading position set on the platen glass of the document reading unit 20, and the document reading unit 20 The document on which the document image is read is discharged onto a document discharge tray. The document reading unit 20 includes a light source that emits light to the document conveyed to the document reading position and a photoelectric conversion element that receives light reflected from the document, and scans a document image corresponding to the size of the document. The photoelectric conversion element converts the received light into image data, which is an electrical signal, and stores it in a memory or outputs it to the image forming unit 30.

  The image forming unit 30 forms an image by a known electrophotographic method. The image forming unit 30 performs various types of data processing such as shading correction on the image data input from the document reading unit 20, and the image data after the data processing is processed. Based on this, an image is formed on the sheet conveyed by the sheet feeding unit 40. The paper feed unit 40 conveys the paper stored in the paper feed tray to the image forming unit 30.

  FIG. 2 is a block diagram illustrating an example of a hardware configuration of the MFP. Referring to FIG. 2, MFP 100 includes a main circuit 101, an ADF 10, a document reading unit 20, an image forming unit 30, a paper feeding unit 40, and an operation panel 9 as a user interface.

  The main circuit 101 includes a CPU 111, a communication interface (I / F) unit 112, a ROM (Read Only Memory) 113, a RAM (Random Access Memory) 114, an EEPROM (Electronically Erasable and Programmable ROM) 115, and a large capacity. A hard disk drive (HDD) 116 as a storage device, a facsimile unit 117, a network I / F 118, and a card I / F 119 in which a flash memory 119A is mounted are included. CPU 111 is connected to ADF 10, document reading unit 20, image forming unit 30, paper feed unit 40, and operation panel 9, and controls the entire MFP 100.

  The ROM 113 stores a program executed by the CPU 111 and data necessary for executing the program. The RAM 114 is used as a work area when the CPU 111 executes a program.

  Communication I / F unit 112 is an interface for connecting MFP 100 to another apparatus using a serial communication cable. The connection form may be wired or wireless.

  The facsimile unit 117 is connected to a public switched telephone network (PSTN) and transmits facsimile data to the PSTN or receives facsimile data from the PSTN. The facsimile unit 117 stores the received facsimile data in the HDD 116 or outputs it to the image forming unit 30. The image forming unit 30 prints the facsimile data received by the facsimile unit 117 on a sheet. Further, the facsimile unit 117 converts the data stored in the HDD 116 into facsimile data, and transmits the facsimile data to a facsimile apparatus connected to the PSTN.

  A network I / F 118 is an interface for connecting the MFP 100 to a network such as a local area network (LAN). The CPU 111 can communicate with a computer connected to the network via the network I / F 118. The network to which the network I / F 118 is connected is not limited to the LAN, but may be the Internet, a wide area network (WAN), a public switched telephone network, or the like.

  The card I / F 119 is mounted with a flash memory 119A. The CPU 111 can access the flash memory 119A via the card I / F 119, and can load a program stored in the flash memory 119A into the RAM 114 and execute it. Note that the program executed by the CPU 111 is not limited to the program stored in the flash memory 119A, but may be a program stored in the HDD 116, and another computer connected to the network via the network I / F 118. The program written in the HDD 116 may be used.

  The storage medium for storing the program is not limited to the flash memory 119A, but an optical disc (CD-ROM (Compact Disk Read Only Memory), MO (Magnetic Optical Disc) / MD (Mini Disc) / DVD (Digital Versatile Disc). ), An IC card, an optical card, a mask ROM, an EPROM (Erasable Programmable ROM), and an EEPROM (Electrically Erasable and Programmable ROM).

  The program here includes not only a program directly executable by the CPU 111 but also a source program, a compressed program, an encrypted program, and the like.

  Operation panel 9 is provided on the upper surface of MFP 100 and includes a display unit 103 and an operation unit 105. FIG. 3 is a plan view showing an example of the operation panel. Referring to FIG. 3, operation panel 9 includes a display unit 103 and an operation unit 105. The display unit 103 is a display device such as a liquid crystal display device or an organic ELD (Electroluminescence Display), and displays an instruction menu for a user, information about acquired display data, and the like.

  The operation unit 105 receives a user operation and outputs the received operation to the CPU 111. The operation unit 105 instructs the touch panel 105A superimposed on the display unit 103, the additional image key 105B to which an operation for instructing execution of an additional image synthesis process to be described later is assigned, and the execution of scan processing. A scan key 105C assigned with an operation to perform, a copy key 105D assigned with an operation for instructing execution of copy processing, a numeric key 105E, a clear key 105F for canceling input contents, and a start key 105G. Including. The touch panel 105 </ b> A is made of a transparent member, and is disposed so as to overlap the display unit 103. When the user touches touch panel 105A with a finger, touch panel 105A detects the touched position as an instruction position and outputs the detected position to CPU 111.

  The EEPROM 115 stores one or more additional images in advance. The additional image is an image including characters, graphics, or a combination thereof, and is a predetermined image. The additional image is, for example, an image including a company logo, page number, date, data file name, and the like. Further, the additional image may be an image including advertisement information when MFP 100 is installed for business use.

  FIG. 4 is a block diagram showing an overview of the functions of the CPU provided in the MFP. The functions of the CPU 111 shown in FIG. 4 are realized by the CPU 111 executing an additional image composition program stored in the ROM 113, the EEPROM 115, the HDD 116, or the flash memory 119A.

  Referring to FIG. 4, CPU 111 includes a condition setting unit 50 that sets processing conditions, a document image acquisition unit 51 that acquires a plurality of pages of document images, and a background region detection that detects a background region of each of the plurality of document images. Unit 53, a common background region extraction unit 55 that extracts a common background region common to a plurality of document images, a background region candidate determination unit 57 that determines one or more candidate positions in the common background region, and one or more candidates A candidate position display unit 65 for displaying a position, a selection unit 91 for selecting one of one or more candidate positions, an additional image acquisition unit 93 for acquiring an additional image, and a candidate position for each of a plurality of document images. A composition unit 95 that synthesizes additional images, a non-background region extraction unit 59 that extracts regions other than the background region from each of a plurality of document images, a common background region enlargement unit 61 that expands a common background region, and document edge order Including the imparting section 63, the.

  The condition setting unit 50 sets processing conditions input by the user to the operation unit 105. Specifically, the condition setting unit 50 displays an additional image setting screen on the display unit 103, accepts a condition that the user inputs to the operation unit 105 according to the displayed additional image setting screen, and sets the accepted condition. To do.

  FIG. 5A is a diagram illustrating an example of the additional image setting screen. Referring to FIG. 5A, an additional image setting screen 201 includes an area 203 for setting an additional image and an area 205 for setting an attribute of the additional area. In the additional image setting area 203, the file name of the additional image is set. Here, a case where an additional image with the file name “aaa.jpg” is set is shown. As described above, the additional image is stored in the EEPROM 115 in advance. When the user designates the inverted triangle mark shown to the right of the area 203, a list of file names of the additional images stored in the EEPROM 115 is displayed, and when the user designates one of the lists, the instruction is given. The file name thus displayed is displayed in the area 203, and an additional image with the file name is set as a processing target.

  In an area 205 in which the attribute of the additional area is set, the attribute of the area to be combined with the additional image is set. Here, one of the three attributes of “background region”, “background region + low density region”, and “high density region” can be selected. The background area is a blank area in which an image composed of characters, figures, or photographs is not represented in the document image. The low density area is an area other than the background area in the document image and includes a pixel having a pixel value smaller than a predetermined value T. The high density region is a region other than the background region in the document image, and includes a pixel having a pixel value equal to or greater than a predetermined value T. The region having the attribute “background region + low concentration region” indicates a region including both the background region and the low concentration region.

  It should be noted that a rectangular character area in which characters are represented, a rectangular graphic area in which graphics are represented, and a rectangular photo area in which photographs are represented are extracted from the original image, respectively. The low density area and the high density area are determined depending on the density of the pixels in the photographic area.

  When “background area” is set in the area 205 in which the attribute of the additional area is set, the condition setting unit 50 displays a background area setting screen on the display unit 103, and in the area 205 in which the attribute of the additional area is set, When “background area + low density area” or “high density area” is set, the condition setting unit 50 displays a density area setting screen on the display unit 103.

  FIG. 5B is a diagram illustrating an example of the background area setting screen. Referring to FIG. 5B, the base area setting screen 211 includes an area 213 for setting an enlargement condition. In the area 213 for setting the enlargement condition, either permission or disapproval can be set. The enlargement condition is an area for setting whether to enlarge an area for compositing an additional image. When “background area” is set in the area 205 in which the attribute of the additional area is set and permission is set in the enlargement condition, it indicates that enlargement of the common background area is permitted.

  FIG. 5C is a diagram illustrating an example of the density area setting screen. Referring to FIG. 5C, density region setting screen 221 includes a region 223 for setting whether or not to superimpose a character region, and a region 225 for setting an enlargement condition. The area 223 for setting whether or not to superimpose a character area is an area for setting whether or not to allow the superimposition of an additional image to the image of the character area in which characters included in the low density area or the high density area are represented. When permission is instructed, the setting is made to allow the superimposition of the additional image to the image in the character area, and when permission is instructed, the setting is made not to allow the superimposition of the additional image to the image in the character area. The

  The area 213 for setting the enlargement condition can be set when the non-permission is instructed in the area 223 for setting whether to superimpose the character area, and sets whether to enlarge the area for compositing the additional image. It is an area to do. When permission is set in the enlargement condition, a setting is made to enlarge a non-character area other than the character area, and when disapproval is set in the enlargement condition, a setting is made not to enlarge a non-character area other than the character area.

  Returning to FIG. 4, the document image acquisition unit 51 acquires a plurality of document images that the document reading unit 20 reads and outputs a plurality of pages of documents. The document image acquisition unit 51 outputs the acquired plurality of document images to the background region detection unit 53, a high density region detection unit 73, a character region extraction unit 79, and a composition unit 95, which will be described later. In addition, when data including a plurality of pages of document images stored in the HDD 116 is instructed by an operation that the user inputs to the operation unit 105, the document image acquiring unit 51 reads out the instructed data from the HDD 116. The original image is acquired. The data including a plurality of pages of document images is not limited to data stored in the HDD 116, but may be data received by the network I / F 118 from another computer, or a flash memory 119A attached to the card I / F 119. May be stored in the data.

  Based on the file name of the additional image set by the condition setting unit 50, the additional image acquisition unit 93 reads the additional image specified by the file name from the EEPROM 115, and sends the read additional image to the combining unit 95 described later. Output. The additional image acquired by the additional image acquisition unit 93 is also used by the background region candidate determination unit 57, the low density region candidate determination 77, and the high density region candidate determination unit 87 described later.

  The background area detection unit 53 detects a background area from each of a plurality of document images input from the document image acquisition unit 51. The base area is a blank area in which characters, figures, photographs, and the like included in the document image are not represented. For example, a rectangular character area in which characters are represented, a rectangular graphic area in which graphics are represented, and a rectangular photo area in which photographs are represented are extracted from the original image, respectively, and the extracted character area, graphic area, and photograph are extracted. An area other than the area is set as a base area. If the background of the document image is white, an area including pixels having a pixel value equal to or larger than a predetermined value may be set as the background area. The background area detection unit 53 outputs the background area detected for each of the plurality of document images to the common background area extraction unit 55 and a background level assignment unit 85 described later.

<When “Background area” is set as the additional area attribute>
When the condition setting unit 50 sets “background region” as the attribute of the additional region, the common background region extraction unit 55 is based on the background region of each of the plurality of document images input from the background region detection unit 53. A ground area common to a plurality of document images is extracted as a common ground area. For example, the background area input from the background area detection unit 53 has the same number of pixels as the original image, the value of the pixel in the background area is set to “1”, and the value of the pixel not in the background area is set to “0”. In the case of image data, the image data of the common background area can be obtained by taking the logical product of the image data of each of the plurality of background areas. The common background area extraction unit 55 outputs the common background area to the background area candidate determination unit 57.

<When the enlargement condition is "Not allowed">
The background region candidate determination unit 57 sets the common background region input from the common background region extraction unit 55 when “background region” is set as the attribute of the additional region and “not permitted” is set as the enlargement condition. Among these, an area where the additional image acquired by the additional image acquisition unit 93 can be combined is determined as a background area candidate. An area in which the additional image acquired by the additional image acquisition unit 93 can be arranged in the common background area may be extracted by moving the additional image in the common background area. When there are a plurality of areas for compositing an additional image in the common background area, the background area candidate determination unit 57 determines all of the plurality of areas as background area candidates. The common background area extraction unit 55 sets the determined position in the document image of one or more background area candidates as candidate positions, and outputs the one or more candidate positions and the common background area to the candidate position display unit 65. The candidate position is output to the document edge rank assigning unit 63. Since the candidate position is determined from the common background area, the candidate position is determined for the background area of all the plurality of document images.

  The document edge rank assigning unit 63 receives one or more candidate background region candidate positions from the background region candidate determining unit 57, and assigns a higher priority to each of the one or more candidate positions as it is closer to the edge of the document image. . Here, the priority order given by the document edge order assigning unit 63 is referred to as the document edge order. The document edge order assigning unit outputs the document edge order assigned to each of the one or more candidate positions to the candidate position display unit 65.

  When “background region” is set as the attribute of the additional region, the candidate position display unit 65 receives one or more candidate positions and a common background region from the background region candidate determination unit 57, and receives from the document edge rank assigning unit 63. The document edge order is input. The candidate position display unit 65 displays on the display unit 103 a selection screen for selecting one or more candidate positions having the same priority order as the document edge order. The selection screen is a screen showing the position of the common background area in the entire document image and one or more candidate positions in the common background area with priority. Specifically, the selection screen includes an outer frame indicating the entire document image, a common background area is arranged in the outer frame, and an additional image with priority is arranged at one or more candidate positions in the common background area. Images included.

<When the enlargement condition is “Permitted”>
The non-background area extraction unit 59 receives the background area of each of the plurality of document images from the background area detection unit 53. The non-background area extraction unit 59 sets an area other than the background area as a non-background area when the condition setting section 50 sets “background area” as the attribute of the additional area and sets the enlargement condition to “permitted”. Extract as Specifically, if the image data of the background area has a pixel value of “1” and the value of a pixel not in the background area is “0”, the pixel value is “1”. By setting the value “0” and the pixel value “0” to “1”, the image data of the non-background region is generated. The non-background area extraction unit 59 outputs a plurality of non-background areas respectively corresponding to a plurality of document images to the common background area enlargement section 61.

  The common background region enlargement unit 61 is input from the non-background region extraction unit 59 when the condition setting unit 50 sets “background region” as the attribute of the additional region and the expansion condition is set to “permitted”. The common ground region is enlarged based on the plurality of non-ground regions. Specifically, a common non-background area common to a plurality of document images is obtained from the logical product of image data of a plurality of non-background areas, and the number of document images having non-background areas not included in the common non-background area is small. Specify the original image. Then, the common background area is expanded by moving or reducing an image including the non-background area in the specified document image.

  Here, the expansion of the common base region will be specifically described. FIG. 6A shows an example of the original image of the first page, and FIG. 6B shows an example of the original image of the second page. The original image 301 on the first page includes two images 303 and 305. In the document image 301 of the first page, the areas of the two images 303 and 305 are non-background areas, and the area other than the two images 303 and 305 is a background area. The document image 311 of the second page includes three images 313, 315, and 317. In the document image 311 of the second page, the areas of the three images 313, 315, and 317 are non-background areas, and the areas other than the three images 313, 315, and 317 are background areas.

  FIG. 7 is a diagram illustrating an example of the common base region. The common background area 221 shown in FIG. 7 includes the background area of the original image 201 of the first page shown in FIG. 6A and the background area of the original image 211 of the second page shown in FIG. This is a common area. In FIG. 7, a non-hatched area 323 is a common base area.

  The enlargement of the common background area is realized by moving or reducing the image of the non-background area. Here, an example will be described in which the common ground region is enlarged by moving or reducing the image 317 included in the document image 311 of the second page shown in FIG. 6B.

  FIG. 8A is a diagram illustrating an example of an original image after moving an image included in the original image of the second page. Referring to FIG. 8A, a second page original image 311A includes an image 317 included in the second page original image 311 shown in FIG. The image 317A moved to the left is included. FIG. 8B shows an example of a common ground region extracted from the first page document image shown in FIG. 6A and the changed second page document image shown in FIG. FIG. It can be seen that the common ground region 323A shown in FIG. 8B is larger than the common ground region 323 shown in FIG.

  FIG. 9A is a diagram illustrating an example of a document image after the image included in the document image of the second page is reduced. Referring to FIG. 9A, document image 311B on the second page includes an image 317B obtained by reducing image 317 included in document image 311 on the second page shown in FIG. 6B. FIG. 9B shows an example of a common ground area extracted from the original image of the first page shown in FIG. 6A and the changed original image of the second page shown in FIG. FIG. It can be seen that the common ground region 323B illustrated in FIG. 9B is larger than the common ground region 323 illustrated in FIG.

  Returning to FIG. 4, the background region candidate determination unit 57 receives an input from the common background region enlargement unit 61 when “background region” is set as the attribute of the additional region and “permission” is set as the expansion condition. Among the enlarged common background regions, a region where the additional image acquired by the additional image acquisition unit 93 can be combined is determined as a background region candidate. When there are a plurality of areas for compositing an additional image in the common background area, the background area candidate determination unit 57 determines all of the plurality of areas as background area candidates. The common background area extraction unit 55 uses the determined position of one or more background area candidates in the document image as a candidate position, and outputs the one or more candidate positions and the enlarged common background area to the candidate position display unit 65. One or more candidate positions are output to the document edge rank assigning unit 63.

  When “background region” is set as the attribute of the additional region, the candidate position display unit 65 receives one or more candidate positions and a common background region from the background region candidate determination unit 57, and receives from the document edge rank assigning unit 63. The document edge order is input. The candidate position display unit 65 displays a selection screen on which one or more candidate positions with priorities can be selected on the display unit 103. The selection screen is a screen showing the position of the common background area in the entire document image and one or more candidate positions in the common background area with priority. Specifically, the selection screen includes an outer frame indicating the entire document, a common background area is arranged in the outer frame, and an additional image with priority is arranged at one or more candidate positions in the common background area. Includes images.

  FIG. 10A is a first diagram illustrating an example of the selection screen. The selection screen shown in FIG. 10A is generated based on the first page original image 331 shown in FIG. 10B as an example and the second page original image 332 shown in FIG. 10C as an example. The selection screen to be displayed is shown. Referring to FIG. 10A, the selection screen 333 includes an outer frame 334 that shows the entire document, a common background area 335 that is arranged in the outer frame 334, and four candidates that are arranged in the common background area 335. Additional images 336 to 339 arranged at the respective positions are included. The additional images 336 to 339 are given a number indicating a priority order and are displayed so as to be selectable. The priority order here is higher as it is closer to the outer frame 334 of the document image.

  Returning to FIG. 4, in the selection unit 91, the user inputs an instruction to select one of the additional images 336 to 339 displayed on the display unit 103 by the candidate position display unit 65 to the operation unit 105. Then, the candidate position corresponding to the additional image selected from the additional images 336 to 339 is selected. The selection unit 91 outputs the selected candidate position to the synthesis unit 95.

  The synthesizer 95 receives a plurality of document images from the document image acquisition unit 51, receives additional images from the additional image acquisition unit 93, and receives candidate positions from the selection unit 91. The combining unit 95 combines the additional image with each of the plurality of document images at the position specified by the candidate position. The combining unit 95 outputs a plurality of document images in which the additional images are combined at the candidate positions to the image forming unit 30, and causes the image forming unit 30 to form a plurality of document images.

  For the original image of the page whose non-background area has been moved or reduced by the non-common background area enlargement section 61, the compositing unit 95 selects an additional image as the original image of the page whose non-background area has been moved or reduced. Composite to the position specified by the position.

  Although an example in which a plurality of document images are formed on the image forming unit 30 is shown here, the output destination of the document image is determined by an instruction input to the operation unit 105 by the user. For example, when an instruction to transmit a document image is input, a plurality of document images in which the additional images are combined are transmitted to the destination specified by the user via the network I / F 118. When an instruction to store an original image is input, a plurality of original images combined with additional images are stored in a flash memory 119A attached to a storage destination instructed by the user, for example, the HDD 116 or the card I / F 119. To remember.

  The CPU 111 further includes a high density area detection unit 73 that detects high density areas of each of the plurality of document images, a logical high density area extraction unit 75, and a character area extraction unit that extracts character areas from each of the plurality of document images. 79, a non-character area enlarging unit 81 for enlarging a non-character area other than the character area, a logical character area extracting unit 83, a low-density area candidate determining unit 77, and a background rank assigning unit 85.

<When “Primary Area + Low Density Area” OR “High Density Area” is set as the attribute of the additional area>
The high density area detection unit 73 detects a high density area from each of the plurality of document images input from the document image acquisition unit 51. The high density region is a region where characters, figures, photographs, etc. included in the document image are represented, and includes a pixel having a pixel value equal to or greater than a predetermined value T. For example, a rectangular character area in which characters are represented, a rectangular graphic area in which graphics are represented, and a rectangular photo area in which photographs are represented are extracted from the original image, respectively, and the extracted character area, graphic area, and photograph are extracted. Of the regions, a region including a pixel having a pixel value equal to or less than a predetermined value T is defined as a high density region. As for the relationship between the pixel value and the density here, the smaller the pixel value, the higher the density, and the larger the pixel value, the lower the density. The high density area detection unit 73 outputs the high density area detected for each of the plurality of document images to the logical OR high density area extraction unit 75 and a high density ranking assignment unit 89 described later.

  The logical OR high density area extraction unit 75 logically determines an area which is a high density area in one or more of the plurality of document images based on the high density areas of the plurality of document images input from the high density area detection unit 73. Extracted as a high-density region. For example, the high density area input from the high density area detection unit 73 has the same number of pixels as the original image, the pixel value of the high density area is set to “1”, and the pixel value not in the high density area is set to “1”. When the image data is “0”, the image data of the logical high density region can be obtained by calculating the logical sum of the image data of each of the plurality of high density regions. The logical high density region extraction unit 75 outputs the logical high density region to the low density region candidate determination unit 77 and a high density region candidate determination unit 87 described later.

<When character area superimposition is set to “permitted”>
The low density region candidate determination unit 77 can synthesize the additional image acquired by the additional image acquisition unit 93 from regions other than the logical high density region input from the logical sum high density region extraction unit 75. This region is determined as a low concentration region candidate. The area other than the logical OR high density area is a low density area or background area that is not a high density area in any of a plurality of document images.

  The low density area candidate determination unit 77 may extract the low density area candidate by moving the additional image in an area other than the logical OR high density area. When there are a plurality of regions where the additional image is synthesized in a region other than the logical OR high concentration region, the low concentration region candidate determination unit 77 determines all of the plurality of regions as low concentration region candidates.

  The low density area candidate determination unit 77 uses the determined position of one or more low density area candidates in the document image as a candidate position, and uses one or more candidate positions and areas other than the logical OR high density area as a candidate position display unit 65. And one or more candidate positions are output to the document edge rank assigning unit 63 and the background rank assigning unit 85.

  The background rank assigning unit 85 receives a plurality of background regions respectively corresponding to a plurality of document images from the background region detection unit 53 and receives one or more candidate positions of one or more low density candidates from the low density region candidate determination unit 77. The The background order assigning unit 85 assigns a higher priority to each of the one or more candidate positions as the number of document images in which the area specified by the candidate position is a background area among a plurality of document images increases. Here, the priority order given by the background order assigning unit 85 is referred to as the background order. The background order assigning unit 85 outputs the background order assigned to one or more candidate positions to the candidate position display unit 65.

  The document edge rank assigning unit 63 receives one or more candidate positions of the low density region candidate from the low density region candidate determination unit 77, and the document edge rank is higher as the one or more candidate positions are closer to the edge of the document image. Is granted.

  The candidate position display unit 65 receives one or more candidate positions and a region other than the logical OR high density region from the low density region candidate determination unit 77, receives the document edge order from the document edge order assignment unit 63, and receives the background order. The background order is input from the assigning unit 85. The candidate position display unit 65 displays a selection screen on which one or more candidate positions with priorities can be selected on the display unit 103. The priority order is determined from the background order input from the background order providing unit 85 and the document end order input from the document end order providing unit 63. Here, the background order has priority over the document edge order. Candidate positions can be selected based on the background order so that the number of document images in which the position where the additional image is combined becomes the background area is as large as possible. Further, based on the document edge order, a candidate position where the position where the additional image is combined is close to the edge of the document can be selected.

  The selection screen is a screen that shows the position of an area other than the logical OR high density area in the entire document image and one or more candidate positions in the area other than the logical OR high density area with priority. Specifically, the selection screen includes an outer frame indicating the entire document, and an area other than the logical OR high density area is arranged in the outer frame, and one or more candidate positions in the area other than the logical OR high density area are arranged. It includes images in which additional images with priorities are arranged.

<When superimposition of the character area is set to “non-permitted”>
The character area extraction unit 79 receives a plurality of document images from the document image acquisition unit 51. In the character area extraction unit 79, “background area + low density area” or “high density area” is set as the additional area attribute by the condition setting unit 50, and the superimposition of the character area is set to “not permitted”. In this case, a character area is extracted from each of a plurality of document images. The character region extraction unit 79 outputs the character region extracted for each of the plurality of document images to the non-character region expansion unit 81 and the logical sum character region extraction unit 83.

  The logical character area extraction unit 83 receives a plurality of character areas respectively corresponding to a plurality of document images from the character area extraction unit 79. Based on the plurality of character regions input from the character region extraction unit 79, the logical character region extraction unit 83 extracts a region that is a character region in one or more of the plurality of document images as a logical character region. For example, the character area input from the character area extraction unit 79 has the same number of pixels as the original image, the value of the pixel in the character area is “1”, and the value of the pixel not in the character area is “0”. In the case of image data, the image data of the logical character area can be acquired by calculating the logical sum of the image data of each of the plurality of character areas. The logical sum character region extraction unit 83 outputs the logical sum character region to the low density region candidate determination unit 77 and a high density region candidate determination unit 87 described later.

<When the enlargement condition is set to “Not allowed”>
The low density area candidate determination unit 77 sets “background area + low density area” as the attribute of the additional area by the condition setting unit 50, sets the superimposition of the character area to “non-permitted”, and sets the enlargement condition Is set to “non-permitted”, an area other than the logical high density area input from the logical high density area extraction unit 75 and a logical character area input from the logical sum character area extraction unit 83 Among the regions other than the region, the region where the additional image acquired by the additional image acquisition unit 93 can be synthesized is determined as a low density region candidate. An area other than the logical OR high density area and other than the logical OR character area is a low density area or background area that is not a high density area and is not a character area in any of a plurality of document images. For this reason, the candidate position is determined as a low-density area or a background area other than the character area, so that it is possible to prevent the character from becoming unreadable.

  The low density area candidate determination unit 77 uses the determined position in the document image of one or more low density area candidates as a candidate position, and is an area other than the one or more candidate positions and the logical high density area, A region other than the region is output to the candidate position display unit 65, and one or more candidate positions are output to the document edge rank assigning unit 63 and the background rank assigning unit 85.

  The background rank assigning unit 85 receives a plurality of background regions respectively corresponding to a plurality of document images from the background region detection unit 53 and receives one or more candidate positions of one or more low density candidates from the low density region candidate determination unit 77. The The background order assigning unit 85 assigns a higher background order to each of the one or more candidate positions as the number of document images whose area specified by the candidate position is a background area among a plurality of document images increases. The background order assigning unit 85 outputs the background order assigned to one or more candidate positions to the candidate position display unit 65.

  The document edge rank assigning unit 63 receives one or more candidate positions of the low density region candidate from the low density region candidate determination unit 77, and the document edge rank is higher as the one or more candidate positions are closer to the edge of the document image. Is granted.

  The candidate position display unit 65 receives one or more candidate positions from the low density region candidate determination unit 77 and an area other than the logical sum high density area and a region other than the logical sum character area. The document edge order is input from 63, and the background order is input from the background order providing unit 85. The candidate position display unit 65 displays a selection screen on which one or more candidate positions with priorities can be selected on the display unit 103. The priority order is determined from the background order input from the background order providing unit 85 and the document end order input from the document end order providing unit 63. Here, the background order has priority over the document edge order.

  The selection screen is a region other than the logical OR high density area in the entire document image, and the priority order is set to the position of the area other than the logical OR character area and one or more candidate positions in the area other than the logical OR high density area. It is a screen attached and shown. Specifically, the selection screen includes an outer frame that indicates the entire document, and an area other than the logical OR high density area that is not the logical OR character area is arranged in the outer frame, and the logical OR high density area is arranged. And an image in which an additional image in which priority is given to one or more candidate positions in an area other than the logical character area is arranged.

<When the enlargement condition is set to “Allow”>
The non-character area enlargement unit 81 enlarges a non-character area other than the character area based on a plurality of character areas respectively corresponding to a plurality of document images input from the character area extraction unit 79. Enlarging a non-character area is a process of moving or reducing a character area of a document image selected from a plurality of document images. The non-character area enlargement unit 81 outputs the character areas of a plurality of document images after moving or reducing the character area to the logical character area extraction unit 83. Here, the character regions of the plurality of document images after the character region is moved or reduced are referred to as character regions after the non-character regions of the plurality of documents are enlarged.

  Specifically, the non-character area enlargement unit 81 obtains a common character area common to a plurality of document images from the logical product of image data of a plurality of character areas, and a document image having a character area not included in the common character area Document images with a small number of are identified. Then, the non-character area enlarging unit 81 moves or reduces the character area in the specified document image.

  The direction in which the non-character area enlarging unit 81 moves in the character area is set when the condition setting unit 50 sets “background area + low density area” as the attribute of the additional area, and when “high density area” is set. It differs depending on the case. When “background area + low density area” is set as the attribute of the additional area, it is on the logical high density area side, and thereby the non-character area in the low density area is enlarged. When “high density area” is set in the attribute of the additional area, the direction is the background area opposite to the logical high density area side, and thereby the non-character area in the high density area is enlarged. .

  The logical character area extraction unit 83 receives the character areas after the non-character areas of a plurality of documents are expanded from the non-character area expansion section 81. A logical character area extraction unit 83 extracts, as a logical character area, a region that is a character region in one or more of a plurality of document images, based on a character region after enlargement of a non-character region of a plurality of documents that is input. . For example, the character area after the non-character area enlargement of a plurality of originals input from the non-character area enlargement unit 81 has the same number of pixels as the original image, and the value of the pixel in the character area is “1”. When the image data having a pixel value of “0” is set to “0”, the logical sum of the image data of each character area after enlargement of the non-character area of a plurality of originals is calculated. Image data of the character area can be acquired. The logical sum character region extraction unit 83 outputs the logical sum character region after the non-character region enlargement to the low density region candidate determination unit 77 and a high density region candidate determination unit 87 described later.

  The low density region candidate determination unit 77 is a region other than the logical sum high density region input from the logical sum high density region extraction unit 75, and is an expanded non-character region input from the logical sum character region extraction unit 83. Of the areas other than the logical character area, an area where the additional image acquired by the additional image acquisition unit 93 can be synthesized is determined as a low density area candidate. An area other than the logical OR high density area and other than the logical OR character area is a background area or a low density area which is not a high density area and is not a character area in any of a plurality of document images. For this reason, the candidate position is determined as a low-density area or a background area other than the character area, so that it is possible to prevent the character from becoming unreadable.

  The low density region candidate determination unit 77 uses the determined position in the document image of one or more low density region candidates as a candidate position, and is a region other than the one or more candidate positions and the logical high density region, The region other than the logical sum character region after the region expansion is output to the candidate position display unit 65, and one or more candidate positions are output to the background rank assigning unit 85 and the document edge rank assigning unit 63.

  For each of one or more candidate positions input from the low-density area candidate determination unit 77, the background order assigning unit 85 counts the number of document images in which a region specified by the candidate position is a background region among a plurality of document images. The higher the number, the higher the background order. The background order assigning unit 85 outputs the background order assigned to one or more candidate positions to the candidate position display unit 65.

  The document edge rank assigning unit 63 receives one or more candidate positions of the low density region candidate from the low density region candidate determination unit 77, and the document edge rank is higher as the one or more candidate positions are closer to the edge of the document image. Is granted.

  The candidate position display unit 65 receives one or more candidate positions from the low density region candidate determination unit 77 and a region other than the logical sum high density region and a region other than the logical sum character region after the non-character region enlargement. Then, the document edge rank is input from the document edge rank assigning unit 63, and the background rank is input from the background rank adding unit 85. The candidate position display unit 65 displays a selection screen on which one or more candidate positions with priorities can be selected on the display unit 103. The priority order is determined from the background order input from the background order providing unit 85 and the document end order input from the document end order providing unit 63. Here, the background order has priority over the document edge order.

  The selection screen is an area other than the logical OR high density area in the entire original image, and the position of the area other than the logical OR character area after the enlargement of the non-character area and the area other than the logical OR high density area. It is a screen which shows one or more candidate positions in an area other than the logical sum character area after the character area has been enlarged with priorities. Specifically, it includes an outer frame indicating the entire document, and an area other than the logical high-density area other than the logical high-density area is arranged in the outer frame, and an area other than the logical character area after the non-character area expansion is arranged. It includes an image in which an additional image with priority is arranged at one or more candidate positions in an area other than the density area and other than the logical character area after the non-character area is enlarged.

  The CPU 111 further includes a high density region candidate determination unit 87 that determines one or more candidate positions in the high density region, and a high density ranking assigning unit 89.

<When character area superimposition is set to “permitted”>
The high density area candidate determination unit 87 selects an area where the additional image acquired by the additional image acquisition unit 93 can be combined from the logical high density area input from the logical high density area extraction unit 75. And determined as a high density region candidate. The logical OR high density area is an area that becomes a high density area in one or more of a plurality of document images.

  The high density area candidate determination unit 87 may extract the high density area candidate by moving the additional image in the logical OR high density area. The high density region candidate determination unit 87 determines all of the plurality of regions as high density region candidates when there are a plurality of regions in which the additional image is synthesized in the logical high density region.

  The high density area candidate determination unit 87 sets the determined position in the document image of one or more high density area candidates as candidate positions, and outputs the one or more candidate positions and the logical high density area to the candidate position display unit 65. One or more candidate positions are output to the document edge rank assigning unit 63 and the high density rank assigning unit 89.

  The high density ranking assigning unit 89 receives a plurality of high density regions respectively corresponding to a plurality of document images from the high density region detection unit 73, and one or more high density region candidate candidate positions from the high density region candidate determination unit 87. Is entered. The high density ranking assigning unit 89 assigns a higher priority to each of one or more candidate positions as the number of document images in which the area specified by the candidate position is a high density area among the plurality of document images increases. . Here, the priority order given by the high density order assigning unit 89 is referred to as a high density order. The high density ranking giving unit 89 outputs the high density ranking given to one or more candidate positions to the candidate position display unit 65.

  The document edge order assigning unit 63 receives one or more candidate positions of the high density region candidate from the high density region candidate determination unit 87, and the document edge order is higher as the one or more candidate positions are closer to the edge of the document image. Is granted.

  The candidate position display unit 65 receives one or more candidate positions and a logical high density region from the high density region candidate determination unit 87, receives the document edge order from the document edge order provision unit 63, and receives the high density order provision unit. From 89, the high density ranking is input. The candidate position display unit 65 displays a selection screen on which one or more candidate positions with priorities can be selected on the display unit 103. The priority order is determined from the high density order input from the high density order assignment unit 89 and the document end order input from the document end order assignment unit 63. Here, the high density order is given priority over the document edge order. Candidate positions can be selected based on the high density order so that the number of document images in which the position where the additional image is combined becomes a high density area is as large as possible.

  The selection screen is a screen showing the position of the logical OR high density area in the entire document image and one or more candidate positions in the logical OR high density area with priority. Specifically, the selection screen includes an outer frame indicating the entire document, an OR high density region is arranged in the outer frame, and one or more candidate positions in the OR high density region are prioritized. Includes images with images.

<When character area superimposition is set to “not allowed” and enlargement condition is set to “not allowed”>
The high density region candidate determination unit 87 sets “high density region” as the attribute of the additional region by the condition setting unit 50, sets “superimpose” of the character region as “not permitted”, and sets “not permitted” as the enlargement condition. When “permitted” is set, the logical high-density region input from the logical sum high-density region extraction unit 75 and the region other than the logical sum character region input from the logical sum character region extraction unit 83 Then, an area where the additional image acquired by the additional image acquisition unit 93 can be synthesized is determined as a high density area candidate. The logical high-density area other than the logical character area is a high-density area in one or more of the plurality of document images and is not a character area in any of the plurality of document images. For this reason, the candidate position is determined to be an area other than the character area, so that it is possible to prevent the character from becoming unreadable.

  The high density area candidate determination unit 87 uses the determined position of one or more high density area candidates in the document image as a candidate position, and is one or more candidate positions, a logical high density area other than the logical character area. The region is output to the candidate position display unit 65, and one or more candidate positions are output to the document edge rank assigning unit 63 and the high density rank assigning unit 89.

  The high density ranking assigning unit 89 receives a plurality of high density regions respectively corresponding to a plurality of document images from the high density region detection unit 73, and one or more candidate positions of one or more high density region candidates from the high density region candidate determination unit 87. Are entered. The high density ranking assigning unit 89 assigns a higher density ranking to each of one or more candidate positions as the number of document images in which the area specified by the candidate position is a high density area among a plurality of document images increases. To do. The high density ranking giving unit 89 outputs the high density ranking given to one or more candidate positions to the candidate position display unit 65.

  The document edge order assigning unit 63 receives one or more candidate positions of the high density region candidate from the high density region candidate determination unit 87, and the document edge order is higher as the one or more candidate positions are closer to the edge of the document image. Is granted.

  The candidate position display unit 65 receives one or more candidate positions and a logical high density region other than the logical sum character region from the high density region candidate determination unit 87 and receives a document from the document edge rank assigning unit 63. The edge rank is input, and the high density rank is input from the high density rank assigning unit 89. The candidate position display unit 65 displays a selection screen on which one or more candidate positions with priorities can be selected on the display unit 103. The priority order is determined from the high density order input from the high density order assignment unit 89 and the document end order input from the document end order assignment unit 63. Here, the high density order is given priority over the document edge order.

  The selection screen is a logical high-density area in the entire original image, the position of an area other than the logical sum character area, and one or more candidates in the logical high-density area other than the logical sum character area. Specifically, the selection screen includes an outer frame that indicates the entire document, and is a logical high-density region in the outer frame, other than the logical character region. An area is arranged and includes an image in which an additional image with priority is assigned to one or more candidate positions in an area other than the logical sum character area, which is a logical high density area.

<When character area superimposition is set to “not allowed” and enlargement condition is set to “permitted”>
The high density region candidate determination unit 87 is a logical high density region input from the logical sum high density region extraction unit 75, and is a logical sum character after expansion of the non-character region input from the logical sum character region extraction unit 83. Of the areas other than the areas, an area where the additional image acquired by the additional image acquisition unit 93 can be combined is determined as a high density area candidate. An area other than the logical sum character area after enlargement of the non-character area, which is the logical sum high density area, is a high density area of one or more of the plurality of document images, and In any case, the area is not a character area. For this reason, since the candidate position is determined in an area other than the character area, it is possible to prevent the character from being unreadable.

  The high density area candidate determination unit 87 uses the determined position in the original image of one or more high density area candidates as a candidate position, and is one or more candidate positions and a logical high density area after the non-character area is enlarged. Are output to the candidate position display unit 65, and one or more candidate positions are output to the high density level assigning unit 87 and the document edge order assigning unit 63.

  The high density ranking assigning unit 89 receives a plurality of high density regions respectively corresponding to a plurality of document images from the high density region detection unit 73, and one or more candidate positions of one or more high density region candidates from the high density region candidate determination unit 87. Are entered. The high density ranking assigning unit 89 assigns a higher density ranking to each of one or more candidate positions as the number of document images in which the area specified by the candidate position is a high density area among a plurality of document images increases. To do. The high density ranking giving unit 89 outputs the high density ranking given to one or more candidate positions to the candidate position display unit 65.

  The document edge order assigning unit 63 receives one or more candidate positions of the high density region candidate from the high density region candidate determination unit 87, and the document edge order is higher as the one or more candidate positions are closer to the edge of the document image. Is granted.

  The candidate position display unit 65 is input with one or more candidate positions and a logical high density region from the high density region candidate determination unit 87 and a region other than the logical character region after the non-character region is enlarged, The document edge rank is input from the rank assigning section 63, and the high density rank is input from the high density rank assigning section 89. The candidate position display unit 65 displays a selection screen on which one or more candidate positions with priorities can be selected on the display unit 103. The priority order is determined from the high density order input from the high density order assignment unit 89 and the document end order input from the document end order assignment unit 63. Here, the high density order is given priority over the document edge order.

  The selection screen displays the position of the logical high-density area in the entire original image other than the logical sum character area after enlargement of the non-character area, and the logical sum character after the logical sum high-density area and non-character area enlargement. It is a screen which shows one or more candidate positions in an area other than the area with priority. Specifically, the selection screen includes an outer frame indicating the entire document, and an area other than the logical sum character area after the enlargement of the non-character area is arranged in the outer frame. It includes an image in which an additional image with priority is placed at one or more candidate positions in a density area other than the logical character area after enlargement of the non-character area.

  FIG. 11 is a second diagram illustrating an example of the selection screen. The selection screen shown in FIG. 11 shows the selection screen when “background region + low density region” is set as the attribute of the additional region. Referring to FIG. 11, the selection screen 341 is an area other than the common background area 343 and the logical OR high-density area, the area 345 other than the common background area 343, and the priorities 1 to 8 are attached. Includes low density region candidates. In the figure, the common ground region 343 is indicated by hatching with a slanting line to the left, and the region 345 is indicated by hatching with a slanting line to the right. The low density area candidates having the priorities of 1 to 4 are displayed inside the common background area 343. The low-density area candidates with the priorities 1 to 4 have higher priorities as they are closer to the edge of the document image. Low density region candidates with priorities of 5 to 8 are displayed inside the region 345. For the low density region candidates with the priorities of 5 to 8, the closer to the edge of the document image, the higher the priorities.

  FIG. 12 is a third diagram illustrating an example of the selection screen. The selection screen shown in FIG. 12 shows the selection screen when “high density region” is set as the attribute of the additional region. Referring to FIG. 12, selection screen 351 includes logical sum high density areas 353 and 355 and high density area candidates 357 assigned a priority of 1. A high density area candidate 357 is displayed in the logical sum high density area 353. Since the logical high density region 355 is smaller than the size of the additional image, the high density region candidate is not arranged.

  FIG. 13 is a flowchart showing an example of the flow of additional image composition processing. 13 is a process executed by the CPU 111 when the CPU 111 executes an additional image synthesis program stored in the ROM 113, the EEPROM 115, the HDD 116, or the flash memory 119A.

  Referring to FIG. 13, CPU 111 determines whether an instruction to synthesize an additional image has been received (step S01). When it is detected that the additional image key 105B assigned in advance to the operation unit 105 is pressed, an instruction to synthesize an additional image is received. The process waits until an instruction to synthesize an additional image is received (NO in step S01). If an instruction to synthesize an additional image is received (YES in step S01), the process proceeds to step S02.

  In step S02, an additional image setting screen is displayed on display unit 103. Here, the additional image setting screen shown in FIGS. 5A to 5C is displayed on the display unit 103. In step S03, it is determined whether an instruction to end the setting has been accepted. If an instruction to end the setting is received, the process proceeds to step S04. If not, the process returns to step S02. In other words, the additional image setting screen is displayed until the setting on the additional image setting screen is completed. When the setting on the additional image setting screen is completed, the process proceeds to step S04.

  In step S04, an additional image designated by the user on the additional image setting screen displayed in step S02 is acquired. In the present embodiment, the additional image is acquired by reading the specified additional image from the additional images stored in advance in the EEPROM 115.

  In the next step S05, the process waits until an original reading instruction is accepted. When the original reading instruction is accepted, the process proceeds to step S06. When it is detected that the start key 105G included in the operation unit 105 is pressed, a document reading instruction is accepted.

  In step S06, the document reading unit 20 is controlled to read the document and acquire a document image. In the next step S07, the process branches depending on the setting of the additional area attribute. If the attribute of the additional area is set to “background area”, the process proceeds to step S08. Otherwise, the attribute of the additional area is set to “background area + low density area” or “high density area”. If so, the process proceeds to step S10. In step S08, a background area is detected from the document image obtained by reading the document in step S06, and the process proceeds to step S09.

  On the other hand, in step S10, as in step S08, the background area is detected from the document image. In the next step S11, a high density region is detected from the document image. In the next step S12, a character area is extracted from the document image, and the process proceeds to step S09. In step S09, it is determined whether or not the next original exists. If there is a document to be read next, the process returns to step S06; otherwise, the process proceeds to step S13.

  In step S13, as in step S07, the process branches depending on the setting of the additional area attribute. If the attribute of the additional area is set to “background area”, the process proceeds to step S14. If the attribute of the additional area is set to “background area + low density area”, the process proceeds to step S14. If the attribute of the additional area is set to “high density area”, the process proceeds to step S15.

  In step S14, a background area candidate determination process is executed, and the process proceeds to step S17. Although details of the background area candidate determination process will be described later, this is a process of determining one or more background area candidates for combining an additional image with the background area detected in step S08.

  In step S15, a low density region candidate determination process is executed, and the process proceeds to step S17. Although details of the low density area candidate determination process will be described later, this is a process of determining one or more low density area candidates for synthesizing an additional image with an area other than the high density area detected in step S11.

  In step S16, a high density region candidate determination process is executed, and the process proceeds to step S17. Although details of the high density area candidate determination process will be described later, this is a process of determining one or more high density area candidates for synthesizing the additional image with the high density area detected in step S11.

  In step S17, it is determined whether any one of the candidate positions determined in any of steps S14, S15, and S16 has been accepted. The process waits until selection of a candidate position is accepted (NO in step S17). If selection of a candidate position is accepted (YES in step S17), the process proceeds to step S18.

  In step S18, the additional image acquired in step S04 is combined with the candidate position selected by the user in step S17 of each of the plurality of document images read in step S06, and the process proceeds to step S19. In step S19, a plurality of document images obtained by combining the additional images are output to the image forming unit 30, and a plurality of document images are formed on a sheet.

  FIG. 14 is a flowchart illustrating an example of the flow of a background area candidate determination process. The background area candidate determination process is a process executed in step S14 of FIG. Referring to FIG. 14, CPU 111 extracts a common base area. Based on the plurality of background areas detected from each of the plurality of document images in step S08 in FIG. 13, a background area common to the plurality of document images is extracted as a common background area.

  In the next step S22, it is determined whether or not the enlargement setting is set to be permitted by the user on the additional image setting screen displayed in step S02 of FIG. If the enlargement setting is set to permit, the process proceeds to step S23; otherwise, the process proceeds to step S25.

  In step S23, a non-background area is detected. Based on the plurality of background areas detected from each of the plurality of document images in step S08 of FIG. 13, a non-background area is detected as a plurality of document images as a non-background area. In the next step S24, the common ground region is enlarged. Specifically, the common background area is expanded by moving or reducing the image included in the non-background area detected in step S23 in a direction different from the background area. In step S24, one or more of the plurality of document images are partially changed.

  In step S25, a background area candidate is determined from the common background area. A position where the additional image acquired in step S04 of FIG. 13 can be combined in the common background area is determined as a background area candidate. If there are a plurality of background area candidates, a plurality of background area candidates are determined. When the process proceeds from step S24, in step S25, a background area candidate is determined from the enlarged common background area.

  In the next step S26, one or more background area candidates determined in step S25 are assigned a higher priority from the one close to the document edge, and the process proceeds to step S27. In step S27, the candidate position is displayed, and the process returns to the additional image composition process. The candidate position indicates the position of the background area candidate in the common background area. Specifically, a selection screen in which one or more background area candidates determined in step S25 are arranged in the common background area is displayed on the display unit 103.

  FIG. 15 is a flowchart illustrating an example of the flow of a low density region candidate determination process. The low density region candidate determination process is a process executed in step S15 of the additional image synthesis process shown in FIG. Referring to FIG. 15, CPU 111 extracts a logical OR high density region (step S31). Specifically, based on the high density area detected from each of the plurality of document images in step S11 of FIG. 13, a region that is a high density area in one or more of the plurality of document images is extracted as a logical OR high density area. To do. In the next step S32, it is determined whether or not the user is permitted to superimpose the character area on the additional image setting screen displayed in step S02 of FIG. If superimposition of the character area is permitted, the process proceeds to step S33. If not, the process proceeds to step S34.

  In step S33, a low density region candidate is determined, and the process proceeds to step S41. Specifically, an area where the additional image can be synthesized is determined as a low density area from areas other than the logical OR high density area extracted in step S31. If there are a plurality of areas in which the additional image can be synthesized, all of the plurality of areas are determined as low density area candidates.

  On the other hand, in step S34, a logical sum character area is extracted. Based on the character areas detected from each of the plurality of document images in step S12 of FIG. 13, a region that is a character region in one or more of the plurality of document images is extracted as a logical character region. In the next step S35, it is determined whether or not the enlargement setting is set to be permitted by the user on the additional image setting screen displayed in step S02 of FIG. If the enlargement setting is set to permit, the process proceeds to step S36; otherwise, the process proceeds to step S40.

  In step S36, it is determined whether there is a movable character area among the character areas included in any of the plurality of document images. The movable character area refers to a character area in which a character area existing in an area other than the logical high density area can be moved into the logical high density area. If there is a movable character area among the character areas included in any of the plurality of document images, the process proceeds to step S37; otherwise, the process proceeds to step S38.

  In step S37, the character area of the document image determined to be movable in step S36 is moved, and the process proceeds to step S39. When the character region to be moved overlaps with a plurality of document images, the character region is moved in all document images including the character region to be moved.

  On the other hand, in step S38, the character area of any of the plurality of document images is reduced, and the process proceeds to step S39. The character area to be reduced may be a character area existing in an area other than the logical high density area. However, as a result of reducing the character area, the non-character area in the area other than the logical OR high density area must be enlarged, and therefore the character area is reduced in all document images having the character area overlapping the character area.

  In step S39, the logical character area is updated, and the process proceeds to step S40. Based on the character regions of the plurality of document images after the character region is moved, the logical character region is extracted in the same manner as that extracted in step S34. In the next step S40, an area other than the high density area where an additional image can be arranged from an area other than the logical character area is determined as a low density area candidate, and the process proceeds to step S41. The logical character area to be processed is the logical character area extracted in step S34 when the process proceeds from step S35, and the logical element updated in step S39 when the process proceeds from step S39. Japanese character area.

  In step S41, when the process proceeds from step S33, one or more low density region candidates determined in step S33, and when the process proceeds from step S40, one or more low density region candidates determined in step S40. The higher priority is assigned in descending order of the number of document images serving as background areas among a plurality of document images.

  In the next step S42, the one or more low density area candidates determined in S33 or the one or more low density area candidates determined in step S41 are assigned a high priority from the one close to the document edge, and the process is performed. Proceed to step S43.

  In the next step S43, candidate positions are displayed, and the process returns to the additional image composition process. The candidate position indicates the position of a low density region candidate in an area other than the logical OR high density area. Specifically, a selection screen in which one or more low-density area candidates determined in step S33 or step S40 are arranged with priority in areas other than the logical OR high-density area is displayed on the display unit 103. The priority order is determined based on the background order given in step S41 and the document edge order given in step S62, and the background order has priority over the document edge order. The document edge order may be given priority over the background order.

  FIG. 16 is a flowchart illustrating an example of the flow of the high density region candidate determination process. The high density region candidate determination process is a process executed in step S16 of the additional image synthesis process shown in FIG. Referring to FIG. 16, CPU 111 extracts a logical OR high density region (step S51). Specifically, based on the high density area detected from each of the plurality of document images in step S11 of FIG. 13, a region that is a high density area in one or more of the plurality of document images is extracted as a logical OR high density area. To do. In the next step S52, it is determined whether or not the user is permitted to superimpose the character area on the additional image setting screen displayed in step S02 of FIG. If superimposition of the character area is permitted, the process proceeds to step S53. If not, the process proceeds to step S54. In step S53, a high density region candidate is determined, and the process proceeds to step S61. Specifically, an area where an additional image can be synthesized is determined as a high density area candidate from the logical high density area extracted in step S51. If there are a plurality of areas in which the additional image can be synthesized, all of the plurality of areas are determined as high density area candidates.

  On the other hand, in step S54, a logical sum character area is extracted. Based on the character areas detected from each of the plurality of document images in step S12 of FIG. 13, a region that is a character region in one or more of the plurality of document images is extracted as a logical character region. In the next step S55, it is determined whether or not enlargement setting is set to be permitted by the user on the additional image setting screen displayed in step S02 of FIG. If the enlargement setting is set to permit, the process proceeds to step S56; otherwise, the process proceeds to step S60.

  In step S56, it is determined whether there is a movable character area among the character areas included in any of the plurality of document images. The movable character area refers to a character area in which a character area existing in the logical sum high density area can be moved out of the logical sum high density area. If there is a movable character area among the character areas included in any of the plurality of document images, the process proceeds to step S57. If not, the process proceeds to step S58.

  In step S57, the character area of the document image determined to be movable in step S56 is moved, and the process proceeds to step S59. When the character region to be moved overlaps with a plurality of document images, the character region is moved in all document images including the character region to be moved.

  On the other hand, in step S58, the character area of any of the plurality of document images is reduced, and the process proceeds to step S59. The character area to be reduced may be a character area existing in the logical high density area. However, as a result of reducing the character area, the non-character area in the logical OR high density area has to be enlarged. Therefore, the character area is reduced in all document images having the character area overlapping the character area.

  In step S59, the logical sum character area is updated, and the process proceeds to step S60. Based on the character regions of the plurality of document images after the character region is moved, the logical character region is extracted in the same manner as that extracted in step S54. In step S60, an area where an additional image can be arranged from a high density area other than the logical sum character area is determined as a high density area candidate, and the process proceeds to step S61. The logical character area to be processed is the logical character area extracted in step S54 when the process proceeds from step S55. If the process proceeds from step S59, the logical character area updated in step S59 is processed. Japanese character area.

  In step S61, if the process proceeds from step S53, one or more high density area candidates determined in step S53, and if the process proceeds from step S60, one or more high density area candidates determined in step S60. Among the plurality of document images, the highest priority is assigned in descending order of the number of document images that become high density regions.

  In step S62, the one or more high density area candidates determined in step S53 or the one or more high density area candidates determined in step S60 are assigned a high priority from the one close to the document edge, and the process is performed. Proceed to S63.

  In the next step S63, candidate positions are displayed, and the process returns to the additional image composition process. The candidate position indicates the position of the high density area candidate in the logical OR high density area. Specifically, a selection screen in which one or more high-density area candidates determined in step S53 or step S60 are given priority in the logical high-density area is displayed on the display unit 103. The priority order is determined based on the high density ranking given in step S61 and the document edge ranking given in step S62, and the high density ranking takes precedence over the document edge ranking. The document edge order may be given priority over the high density order.

  In the above-described embodiment, MFP 100 has been described as an example of an image processing apparatus. However, an additional image composition method for causing MFP 100 to execute the additional image composition processing illustrated in FIGS. It goes without saying that the invention can be understood as an additional image composition program for causing a computer to execute the composition method.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

<Appendix>
(1) A document reading unit that reads a plurality of pages of documents and outputs a plurality of document images,
The image processing apparatus according to claim 1, wherein the document image acquisition unit acquires a plurality of document images output by the previous document reading unit.
(2) The image processing device according to claim 1 or 2, wherein the candidate position display unit displays an image in which the additional image is superimposed on a candidate position in the common ground region.
(3) The image processing apparatus according to any one of claims 3 to 6, wherein the candidate position display unit displays an image in which the additional image is superimposed on a candidate position in the low density region.
(4) The image processing device according to any one of claims 7 to 11, wherein the candidate position display unit displays an image in which the additional image is superimposed on a candidate position of the high density region.

DESCRIPTION OF SYMBOLS 10 ADF, 20 Original reading part, 30 Image formation part, 40 Paper feed part, 50 Condition setting part, 51 Original image acquisition part, 53 Background area detection part, 55 Common background area extraction part, 57 Background area candidate determination part, 59 Non-background region extraction unit, 61 Common background region enlargement unit, 63 Document edge rank assignment unit, 65 Candidate position display unit, 73 High density region detection unit, 75 OR high density region extraction unit, 77 Low density region candidate determination unit, 79 character region extraction unit, 81 non-character region expansion unit, 83 logical sum character region extraction unit, 85 background rank assignment unit, 87 high density region candidate determination unit, 89 high density rank addition unit, 91 selection unit, 93 additional image acquisition Part, 95 composition part, 100 MFP, 101 main circuit, 103 display part, 105 operation part, 111 CPU, 112 communication I / F part, 113 ROM, 114 RAM, 115 EEPROM 116 HDD, 117 facsimile unit, 118 network I / F, 119 card I / F, 119A flash memory.

Claims (17)

Document image acquisition means for acquiring a document image of a plurality of pages;
Detecting means for detecting a background area of each of the plurality of document images;
Extracting means for extracting a common ground region common to the plurality of document images;
Additional image acquisition means for acquiring the additional image;
Background area candidate determination means for determining one or more candidate positions for adding the acquired additional image in the common background area;
Candidate position display means for displaying the determined one or more candidate positions;
Selecting means for selecting one of the one or more candidate positions;
An image processing apparatus comprising: a combining unit configured to combine the additional image with the selected candidate position of each of the plurality of document images. A non-background area extracting means for extracting an area other than the background area from each of the plurality of document images;
A common ground area enlarging means for enlarging the common ground area by moving or reducing any one non-background area of the plurality of document images;
The image processing apparatus according to claim 1, wherein the first candidate position determination unit determines one or more candidate positions in the enlarged common ground region. Document image acquisition means for acquiring a document image of a plurality of pages;
Logical OR high density area extraction means for extracting a logical OR high density area having an image density of a predetermined value or more in one or more of the plurality of document images;
Additional image acquisition means for acquiring the additional image;
Low density region candidate determination means for determining one or more candidate positions for adding the acquired additional image in a low density region other than the extracted logical sum high density region;
Candidate position display means for displaying the determined one or more candidate positions;
Selecting means for selecting one of the one or more candidate positions;
An image processing apparatus comprising: a combining unit configured to combine the additional image with the selected candidate position of each of the plurality of document images.   4. The image processing apparatus according to claim 3, further comprising: a background rank assigning unit that assigns a higher priority to the one or more candidate positions as the number of document images whose candidate areas are background areas among the plurality of document images increases. The image processing apparatus described. A character area detecting means for detecting a character area from each of the plurality of document images;
OR character area extraction means for extracting an OR character area extracted as a character area in one or more of the plurality of document images;
5. The image processing apparatus according to claim 3, wherein the low-density area candidate determining unit determines the candidate position within a non-character area other than the logical character area within the low-density area. Non-character area enlarging means for enlarging the non-character area by moving or reducing any one character area of the plurality of document images;
The image processing apparatus according to claim 5, wherein the low-density area candidate determination unit determines one or more candidate positions in the non-character area after the enlargement. Document image acquisition means for acquiring a document image of a plurality of pages;
Logical OR high density area extraction means for extracting a logical OR high density area having an image density of a predetermined value or more in one or more of the plurality of document images;
Additional image acquisition means for acquiring the additional image;
High density region candidate determining means for determining one or more candidate positions for adding the acquired additional image in the extracted high density region;
Candidate position display means for displaying the determined one or more candidate positions;
Selecting means for selecting one of the one or more candidate positions;
An image processing apparatus comprising: a combining unit configured to combine the additional image with the selected candidate position of each of the plurality of document images.   High density ranking assigning means for giving higher priority to the one or more candidate positions as the number of document images in which the candidate area is the high density area among the plurality of document images increases. The image processing apparatus according to claim 7. A character region extracting means for extracting a character region from each of the plurality of document images;
OR character area extraction means for extracting an OR character area to be a character area extracted from one or more of the plurality of document images;
The image processing according to claim 7 or 8, wherein the high-density area candidate determining unit determines the candidate position in a non-character area other than the logical sum character area in the extracted high-density area. apparatus. Non-character area enlarging means for enlarging the non-character area by moving or reducing any one character area of the plurality of document images;
The image processing apparatus according to claim 9, wherein the high-density area candidate determining unit determines one or more candidate positions in the non-character area after the enlargement.   The image processing apparatus according to claim 1, further comprising an edge part rank assigning unit that assigns a higher priority to the determined one or more candidate positions closer to the edge part of the document. Obtaining a multi-page document image;
Detecting a background area of each of the plurality of document images;
Extracting a common ground area common to the plurality of document images;
Obtaining an additional image;
Determining one or more candidate positions for adding the acquired additional image within the common ground region;
Displaying the determined one or more candidate positions;
Selecting one of the one or more candidate positions;
Combining the additional image with the selected candidate position of each of the plurality of document images. Obtaining a multi-page document image;
Extracting a logical OR high density region having an image density equal to or higher than a predetermined value in one or more of the plurality of document images;
Obtaining an additional image;
Determining one or more candidate positions for adding the acquired additional image in a low density region other than the extracted logical high density region;
Displaying the determined one or more candidate positions;
Selecting one of the one or more candidate positions;
Combining the additional image with the selected candidate position of each of the plurality of document images. Obtaining a multi-page document image;
Extracting a logical OR high density region having an image density equal to or higher than a predetermined value in one or more of the plurality of document images;
Obtaining an additional image;
Determining one or more candidate positions for adding the acquired additional image within the extracted high density region;
Displaying the determined one or more candidate positions;
Selecting one of the one or more candidate positions;
Combining the additional image with the selected candidate position of each of the plurality of document images. Obtaining a multi-page document image;
Detecting a background area of each of the plurality of document images;
Extracting a common ground area common to the plurality of document images;
Obtaining an additional image;
Determining one or more candidate positions for adding the acquired additional image within the common ground region;
Displaying the determined one or more candidate positions;
Selecting one of the one or more candidate positions;
And a step of synthesizing the additional image with the selected candidate position of each of the plurality of document images. Obtaining a multi-page document image;
Extracting a logical OR high density region having an image density equal to or higher than a predetermined value in one or more of the plurality of document images;
Obtaining an additional image;
Determining one or more candidate positions for adding the acquired additional image in a low density region other than the extracted logical high density region;
Displaying the determined one or more candidate positions;
Selecting one of the one or more candidate positions;
And a step of synthesizing the additional image with the selected candidate position of each of the plurality of document images. Obtaining a multi-page document image;
Extracting a logical OR high density region having an image density equal to or higher than a predetermined value in one or more of the plurality of document images;
Obtaining an additional image;
Determining one or more candidate positions for adding the acquired additional image within the extracted high density region;
Displaying the determined one or more candidate positions;
Selecting one of the one or more candidate positions;
And a step of synthesizing the additional image with the selected candidate position of each of the plurality of document images.

Images