JP2020174241A - Image reading device and control program thereof - Google Patents

Abstract

To provide an image reading device and a control program thereof which can improve the convenience.SOLUTION: A multifunction peripheral (MFP) as an image reading device includes an image reading unit 20 that acquires a reading image including images of a plurality of documents arranged on a platen, a document overlap detection unit 112 that detects the presence or absence of overlap between documents on the basis of the reading image, a foreground image identification unit 113 that identifies the image of the foreground document which is a document closest to the platen among the plurality of overlapping documents when the overlap between documents is detected, a foreground image storage unit 114 that stores the image of the foreground document, and a relocation notification unit 115 that requests the removal of the foreground document among the plurality of overlapping documents, and requests the rearrangement of the documents other than the foreground document among the plurality of overlapping documents.SELECTED DRAWING: Figure 2

Description

The present invention relates to an image reader and a control program for the image reader. More specifically, the present invention relates to an image reader and a control program for the image reader, which can improve convenience.

The image reading device irradiates the original with light, receives the light reflected by the image of the original, and reads the image. In recent years, an increasing number of companies are trying to improve work efficiency by converting the materials to be stored from printed matter to data due to the improvement of global environmental awareness, cost saving, or the spread of PCs (Personal Computers) and tablets. There is. In this case, the conversion to data is performed by reading the image of the printed matter with an image reading device. Some image forming devices are equipped with an automatic document feeder (ADF (Auto Document Feeder)).

When reading an image of a small-sized document such as a receipt or a photograph, the user places a plurality of documents on the platen (platen glass) of the image reading device in order to improve work efficiency, and the image reading device is used. Gives an instruction to execute image reading. Upon receiving this instruction, the image scanning device generates a scanned image including images of a plurality of originals by one scanning operation.

In particular, when the manuscript is a receipt or the like, there are various sizes and shapes of the manuscript. Therefore, when the original is a receipt or the like, it is often difficult to read the image of the original by passing the original through the automatic document feeder. Therefore, the user arranges a plurality of documents on the platen of the image reading device to obtain a scanned image including images of the plurality of documents.

A technique for detecting the overlap of documents when a plurality of documents are arranged on a platen is disclosed in Patent Document 1 and the like below. In Patent Document 1 below, when the position detection result of the original is recognized as a polygon of pentagon or more, an error is displayed as if the originals overlap, and the user is warned to confirm the position of the printed original. Is disclosed.

Japanese Unexamined Patent Publication No. 2004-260457

FIG. 20 is a diagram illustrating a conventional problem when a plurality of document MSs are arranged on a platen.

With reference to FIG. 20, the placement of the manuscript MS on the platen is done manually by the user. As shown in FIG. 20A, the plurality of document MSs are arranged in the reading area (area in which the image reading device can read the image) R0 on the platen so as not to overlap each other. When the total area of the plurality of document MSs is as large as the area of the reading area R0, as shown in FIG. 20 (b), the documents on the platen overlap each other (the middle area OP in FIG. 20 (b)). The part indicated by) may occur. When the image of the original is read with the originals overlapping each other, the originals other than the frontmost (closest to the platen) original among the plurality of overlapping originals MS are on the frontmost original. The image of the part overlapping with is missing from the scanned image.

In the conventional technique such as Patent Document 1, when the originals overlap each other, the user arranges all of the plurality of original MSs on the platen so that the originals do not overlap each other as shown in FIG. 20 (c). It was necessary to fix and have the image reader read all the images of the plurality of document MSs again. However, when the total area of the plurality of document MSs is as large as the area of the reading area R0, the distance between the documents is narrow. Therefore, as shown in FIG. 20 (d), even after the original MS is rearranged, the originals may overlap each other (the portion shown by the middle region OP in FIG. 20 (d)), which is not convenient. There was a problem.

The present invention is for solving the above problems, and an object of the present invention is to provide an image reading device and a control program for the image reading device, which can improve convenience.

The image reading device according to one aspect of the present invention detects the presence or absence of overlap between the originals based on the acquisition means for acquiring the scanned image including the images of a plurality of originals arranged on the platen and the scanned image. When the overlap detection means and the overlap detection means detect the overlap between the originals, the image of the frontmost original, which is the side closest to the platen among the plurality of overlapping originals, is specified. The foreground specifying means, the saving means for saving the image of the foreground original, and the foremost of the overlapping originals are requested to be removed from the foremost originals. It is provided with a requesting means for requesting the rearrangement of a document other than the original.

The image reading device preferably further includes a receiving means for receiving a setting indicating that a plurality of documents are arranged on the platen, and when the setting is received by the receiving means, the overlap detecting means overlaps the documents. Detects the presence or absence of the occurrence of.

In the image scanning device, preferably, the document region, which is the document region in the scanned image and in which a plurality of documents arranged on the platen exist, is specified based on the distribution of the brightness level in the scanned image. The document area specifying means is further provided, and the overlap detecting means detects the presence or absence of overlapping of documents based on the image of the document area.

In the above image reading device, preferably, the overlap detecting means is specified by the first vertex specifying means for specifying the vertices whose line segments are orthogonal to each other from the contour of the document region and the first vertex specifying means. It includes a vertex detecting means for detecting the presence or absence of overlap between documents in the document area based on whether or not the vertices form a rectangle.

In the above image reading device, preferably, the frontmost specifying means is an exclusion means for excluding pixels having a brightness level within the first range of the image in the document area from the image in the document area, and after exclusion by the exclusion means. When the second vertex specifying means for specifying the vertices from the outline of the new image and the vertices specified by the second vertex specifying means form a rectangle, the new image is the image of the foreground original. When the first foreground determination means for determining that and the vertex specified by the second vertex identification means do not form a rectangle, the second foreground for determining that the new image is not the image of the foreground original. Including means of judgment.

In the image reading device, the exclusion means preferably includes a peak specifying means for specifying a peak brightness level among a plurality of brightness levels of the image in the document region, and a first lightness level specified by the peak specifying means. Includes a pixel exclusion means that excludes pixels having a brightness level within the range of from the image in the document area.

In the image reading device, preferably, the foreground identification means is based on the third vertex specifying means for specifying the vertices perpendicular to the contour of the document region and the coordinates of the vertices specified by the third vertex specifying means. , Estimated by an estimation means for estimating a plurality of vertices and line segments constituting the contour of an overlapping document but not included in the contour of the document area, and an estimation means. Based on the change in the brightness level of the image of the document area at each position of the plurality of line segments, the line segment constituting the outline of the frontmost document is specified from the plurality of line segments estimated by the estimation means. It includes a line segment specifying means and an image specifying means for specifying an image of a rectangular area defined by a line segment specified by the line segment specifying means as an image of a foreground original.

In the above image reading device, preferably, the line segment identifying means indicates the brightness level in the image of the document region along the direction perpendicular to the extending direction of the line segments for each of the plurality of line segments estimated by the estimating means. A plurality of lines estimated by the estimation means based on the detection results of the edge detection means for detecting the presence or absence of the edge at the position where is changed and the edge detection means for each of the plurality of line segments estimated by the estimation means. It includes an edge specifying means for specifying a line segment constituting the outline of the frontmost document from among the minutes.

In the above image reading device, preferably, the requesting means is a reversing means for reversing the image of the document area with the main scanning direction or the sub-scanning direction as a reference line, and the frontmost document in the image after being reversed by the reversing means. The rearrangement specifying means for specifying the image other than the image of the foreground original after reversing by the reversing means as the original to be removed and the removal of the original to be removed. And a rearrangement requesting means for requesting the rearrangement of the original to be rearranged.

In the above image reading device, preferably, the rearrangement requesting means displays the original to be removed and the original to be rearranged in the image of the original area after being inverted by the reversing means in different modes. Request the removal of the original and the rearrangement of the original to be rearranged.

The image reader preferably further includes a document retainer that is rotatable about a hinge and is capable of taking an open state that exposes the platen and a closed state that covers the platen.

The control program of the image reader according to another aspect of the present invention detects the overlap between the originals based on the acquisition step of acquiring the scanned image including the images of a plurality of originals arranged on the platen and the scanned image. When the overlap detection step and the overlap detection step detect the overlap between documents, the frontmost image of the foreground document, which is the document closest to the platen among the plurality of documents with overlap, is specified. A specific step, a save step to save the image of the foreground original, and a request to remove the foremost original among the overlapping originals, and the foremost of the overlapping originals. Have the computer perform a request step that requests the rearrangement of the manuscript other than the manuscript.

According to the present invention, it is possible to provide an image reading device and a control program for the image reading device, which can improve convenience.

It is sectional drawing which shows typically the structure of the MFP1 in one Embodiment of this invention. It is a block diagram which shows the structure of the control part 100 in one Embodiment of this invention. It is the first figure explaining the problem peculiar to the image reading apparatus provided with the document holder. FIG. 2 is a second diagram illustrating a problem peculiar to an image reader provided with a document retainer. It is a flowchart which shows the operation of the MFP1 in one Embodiment of this invention. It is a figure explaining the process (S4) of specifying the document area of FIG. This is a subroutine of the process (S4) for specifying the document area of FIG. It is a figure explaining the process (S5) of detecting the overlap of the documents of FIG. This is a subroutine of the process (S5) for detecting the overlap of the documents of FIG. It is a figure explaining the process (S7) for specifying the foreground image of FIG. This is a subroutine of the process (S7) for specifying the foreground image of FIG. FIG. 1 is a first diagram illustrating a modified example of the process (S7) for specifying the foreground image of FIG. FIG. 2 is a second diagram illustrating a modified example of the process (S7) for specifying the foreground image of FIG. It is a figure which shows the relationship between the edge detection result and the specified foreground image in the modification of the process (S7) which specifies the foreground image of FIG. This is a subroutine of a modified example of the process (S7) for specifying the foreground image of FIG. It is a figure explaining the process (S9) of notifying the occurrence of overlap of the originals of FIG. FIG. 5 is a diagram schematically showing a screen displayed on the operation panel 70 in the process (S9) of notifying the occurrence of overlapping of documents in FIG. 5. This is a subroutine of the process (S9) for notifying the occurrence of overlap between the documents of FIG. It is a figure explaining the effect of one Embodiment of this invention. It is a figure explaining the conventional problem in the case of arranging a plurality of document MSs on a platen.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

In the following embodiment, a case where the image reading device is an MFP (Multifunction Peripheral) will be described. The MFP is an electrophotographic image forming apparatus having a scanner function, a facsimile function, a copying function, a printer function, a data communication function, and a server function. The image reading device may be a scanner, a copying machine, or the like, as well as an MFP.

[MFP configuration]

First, the configuration of the MFP 1 in the present embodiment will be described.

FIG. 1 is a cross-sectional view schematically showing the configuration of the MFP 1 according to the embodiment of the present invention.

With reference to FIG. 1, the MFP 1 (an example of an image reading device) in the present embodiment includes an automatic document feeding device 10 (an example of a document holder), a document reading unit 20 (an example of an acquisition means), and an image forming unit. 30, automatic double-sided unit 40, paper feed unit 50, paper feed cabinet 60, operation panel 70 (an example of reception means), facsimile unit 90, communication interface (I / F) unit 91, and control unit. It is equipped with 100, an HDD (Hard Disk Drive) 120, and the like.

The automatic document feeder 10 automatically feeds a plurality of documents set on the document paper feed tray 12 one by one. The automatic document feeder 10 conveys the fed original to a predetermined image reading position set on the platen (platen glass) 20a (an example of the platen) of the document reading unit 20, and then the document ejection tray 13 Drain up.

The automatic document feeder 10 includes a document set sensor 11. The document set sensor 11 is composed of a known tact switch. The document set sensor 11 detects whether or not a document has been set in the document input tray 12, and transmits the detection result as a signal to the control unit 100. The automatic document feeder 10 can be opened and closed, and also functions as a document retainer when a document is placed on the platen 20a.

The document reading unit 20 reads the image of the document conveyed by the automatic document feeder 10 at the image scanning position. Further, the document reading unit 20 reads an image of the document arranged on the platen 20a. The document reading unit 20 scans the image of the document according to the size of the document conveyed to the image scanning position, converts the incident light into an electric signal, and sends it to the control unit 100 as scanning data.

The document reading unit 20 includes a platen 20a, an IR module 20b, a drive transmission unit 20c, an IR motor 20d, and the like.

The IR module 20b can be moved (scanned) in the lateral direction in FIG. 1 along the platen 20a by the IR motor 20d and the drive transmission unit 20c such as a belt or a wire. Further, the IR module 20b has a lamp 20e for irradiating the document with light and an image sensor 20f for receiving the reflected light from the document. The lamp 20e scans the document arranged on the platen 20a, and the image sensor 20f receives the reflected light from the document. As a result, the IR module 20b reads the image of the original and acquires the image data.

The document reading unit 20 includes a device lifting sensor 21. The device lifting sensor 21 is composed of a known magnetic sensor. The device lifting sensor 21 detects whether or not the automatic document feeder 10 is opened (detects whether or not the platen 20a is exposed), and transmits the result as a signal to the control unit 100.

The image forming unit 30 forms an image on paper by an electrophotographic method. The image forming unit 30 includes the photoconductor drums 31a, 31b, 31c, and 31d, the exposure scanning units 32a, 32b, 32c, and 32d, the transfer belt 33, and the front door cover for protecting these members (not shown). (None) and the front door sensor 34 are included.

Each of the photoconductor drums 31a, 31b, 31c, and 31d corresponds to the colors Y (yellow), M (magenta), C (cyan), and K (black). Similarly, each of the exposure scanning units 32a, 32b, 32c, and 32d corresponds to each color of YMCK.

Each of the exposure scanning units 32a, 32b, 32c, and 32d generates a laser beam based on a drive signal output from the control unit 100, and the generated laser beam is used for each of the photoconductor drums 31a, 31b, 31c, and 31d. The surface of the surface is exposed and scanned. As a result, an electrostatic latent image is formed on the surface of each of the photoconductor drums 31a, 31b, 31c, and 31d. After that, the electrostatic latent images on the surfaces of the photoconductor drums 31a, 31b, 31c, and 31d are developed with toner to become toner images. The toner images formed on the surfaces of the photoconductor drums 31a, 31b, 31c, and 31d are transferred onto the transfer belt 33 so as to overlap each other. The toner image superimposed on the transfer belt 33 is transferred to the paper conveyed by the paper feed unit 50 at the image forming position 35.

The front door sensor 34 is composed of a tact switch. The front door sensor 34 detects whether or not the front door cover has been opened, and transmits the detection result as a signal to the control unit 100.

The automatic double-sided unit 40 temporarily switches back the paper after the image is formed on one side at the image forming position 35 on the paper passing path, and feeds the paper back to the image forming position 35. This enables double-sided printing on paper.

The paper feeding unit 50 conveys the paper to the image forming unit 30. The paper feeding unit 50 includes paper cassettes 51 and 53 for storing paper, and pickup rollers 52 and 54 for feeding the paper stored in each of the paper cassettes 51 and 53.

The paper feed cabinet 60 conveys paper to the image forming unit 30 via the paper feed unit 50. The paper feed cabinet 60 includes paper feed cassettes 61 and 63 for storing paper, and pickup rollers 62 and 64 for feeding paper stored in each of the paper feed cassettes 61 and 63.

The operation panel 70 is a known user interface, and includes a display unit 71, a touch panel input unit 72, a key input unit 73, and an auxiliary power switch 80. The display unit 71 displays various information. The touch panel input unit 72 detects various inputs (operations) to the display unit 71. The key input unit 73 detects the pressing of various hardware keys. The sub power switch 80 is a switch for directly instructing the user to shift to the sleep mode, which is a power saving operation mode.

The facsimile unit 90 is connected to a public telephone line and transmits / receives various data such as image data.

The control unit 100 controls the entire MFP1. When executing the copy job, the control unit 100 performs various data processing such as shading correction on the scanned data received from the document scanning unit 20. The control unit 100 reads out the read data after data processing for each main scanning line in synchronization with the paper supply, and sends a signal for driving the laser diodes of the exposure scanning units 32a, 32b, 32c, and 32d. Output.

The communication interface unit 91 is an interface for communicating with a device such as a PC (Personal Computer) connected to an external network such as a LAN or a device connected through a USB terminal.

The HDD 120 stores various information such as image data transmitted from the control unit 100.

FIG. 2 is a block diagram showing a configuration of a control unit 100 according to an embodiment of the present invention.

With reference to FIG. 2, the control unit 100 includes a CPU (Central Processing Unit) 101, a ROM (Read Only Memory) 102, a RAM (Random Access Memory) 103, and a document area specifying unit 111 (manuscript area specifying means). (Example), document overlap detection unit 112 (an example of overlap detection means), frontmost image identification unit 113 (an example of frontmost frontal identification means), frontmost image storage unit 114 (an example of storage means), and rearrangement. It includes a notification unit 115 (an example of requesting means).

The CPU 101 operates according to the control program and controls the entire MFP1.

The ROM 102 stores the control program.

The RAM 103 is a working memory of the CPU 101, and temporarily stores various data.

When the CPU 101 receives an image scanning execution instruction (scanning instruction) from the user through the operation panel 70, the document scanning unit 20 reads the image of the document arranged on the platen 20a, and the scanned image (reading area). Image) is generated.

In each of the document area identification unit 111, the document overlap detection unit 112, the frontmost image identification unit 113, the frontmost image storage unit 114, and the rearrangement notification unit 115, the CPU 101 transmits a control program stored in the ROM 102 to the RAM 103. It is a functional configuration realized by loading and executing.

The document area specifying unit 111 is a document area in the scanned image based on the distribution of the brightness level in the scanned image (difference in brightness level between the background background in the scanned area and the gradation data), and is on the platen 20a. The document area, which is the area where a plurality of documents arranged in the above exists, is specified.

The document overlap detection unit 112 detects whether or not the documents overlap with each other based on the scanned image (the image of the document area in the present embodiment). The document overlap detection unit 112 identifies vertices in the contour of the document area where the directions of the line segments are orthogonal to each other, and detects whether or not the documents overlap with each other based on the specified vertices.

The foreground image specifying unit 113 is an image of the foreground document which is the document closest to the platen 20a among the plurality of documents in which the overlap occurs when the overlap detection unit 112 detects the overlap between the documents. To identify.

The foreground image storage unit 114 stores the image of the foreground original document specified by the foreground image identification unit 113 in the HDD 120.

The rearrangement notification unit 115 notifies that the documents are overlapped with each other when the plurality of documents arranged on the platen 20a are overlapped with each other. In addition, the removal of the foreground original among the plurality of overlapping originals is requested, and the rearrangement of the originals other than the foremost original is requested. The rearrangement notification unit 115 notifies the user by displaying a screen including information on the removal and rearrangement of the original on the operation panel 70.

[Problems peculiar to image readers equipped with a document holder]

Next, a problem peculiar to an image reader provided with a document retainer will be described.

3 and 4 are diagrams illustrating a problem peculiar to an image reader provided with a document retainer.

With reference to FIG. 3, the document retainer 1010 is a member corresponding to the automatic document feeder 10 of the present embodiment. The document holder 1010 is rotatable about the hinge 1010a. The document retainer 1010 can be in an open state in which the platen 1020a is exposed and in a closed state in which the platen 1020a is covered.

When a user obtains a scanned image of a plurality of manuscripts (receipts, receipts, etc.) MS, as shown in FIG. 3A, the user arranges the plurality of manuscript MSs on the platen 1020a with the manuscript holder 1010 open. .. Then, the user closes the document holder 1010 as shown by the arrow G and gives an instruction to execute image reading. At this time, the plurality of document MSs are arranged in the reading region on the platen 1020a so as not to overlap each other.

Here, when the document MS is folded or curled, the document MS is pushed by the document retainer 1010 from above and stretched. As a result, as shown in FIG. 3B, a plurality of document MSs are likely to overlap each other.

Refer to FIG. 4, and when closing the document retainer 1010 as shown by an arrow G in FIG. 4 (a), an air flow between the document retainer 1010 and the platen 1020a (in the middle dotted line in FIG. 4A). Arrow) occurs. Each of the plurality of document MSs is blown by this air flow and moves in a direction away from the hinge 1010a. Since the amount of movement of each of the plurality of document MSs differs from each other depending on the magnitude and direction of the air flow, the plurality of document MSs are likely to overlap each other as shown in FIG. 4 (b).

As described above, in the image reading device provided with the document retainer, when a plurality of documents are arranged on the platen 1020a, the documents are particularly likely to overlap each other. In the present invention, the manuscript holder is not essential and may be omitted.

[Overview of MFP operation]

Subsequently, an outline of the operation of the MFP 1 will be described.

FIG. 5 is a flowchart showing the operation of the MFP 1 according to the embodiment of the present invention.

With reference to FIG. 5, the user makes various settings related to image reading and gives instructions for executing image reading through the setting screen displayed on the operation panel 70 with the document placed on the platen 20a. When the control unit 100 receives an image scanning execution instruction through the operation panel 70 (S1), the control unit 100 receives an execution instruction for reading images of a plurality of documents (setting indicating that a plurality of documents are arranged on the platen 20a). It is determined whether or not it is contained in (S2).

In step S2, when it is determined that the setting for reading the images of a plurality of documents is not included in the execution instruction (NO in S2), the control unit 100 performs a normal reading operation. That is, the control unit 100 reads the image of the original (S10) and saves the read image in the HDD 120 (S11). After that, the control unit 100 ends the process.

When it is determined in step S2 that the execution instruction includes the setting for reading the images of a plurality of documents (YES in S2), the control unit 100 reads the images of the plurality of documents arranged on the platen 20a. An image is acquired (S3), a document area is specified from the scanned image (S4), and the presence or absence of overlapping of documents is detected (S5). Subsequently, the control unit 100 determines whether or not the occurrence of overlapping of the originals is detected in the process of step S5 (S6).

When it is determined in step S6 that the occurrence of overlapping of the originals is not detected (NO in S6), the plurality of originals arranged on the platen 20a are in a state where the overlapping of the originals does not occur. In this case, the control unit 100 saves the read image in the HDD 120 (S11) and ends the process.

When it is determined in step S6 that the occurrence of overlapping of the originals is detected (YES in S6), the plurality of originals arranged on the platen 20a are in a state of overlapping originals. In this case, the control unit 100 identifies the image of the frontmost document among the plurality of documents (S7), and saves the image of the identified frontmost document in the HDD 120 (S8). Subsequently, the control unit 100 notifies the occurrence of overlapping of the original documents (S9), and ends the process.

[Process to specify the original area]

FIG. 6 is a diagram illustrating a process (S4) for specifying the document area of FIG. Note that in FIGS. 6 and 10, the difference in brightness level is shown by the difference in hatching.

With reference to FIG. 6, in the present embodiment, the brightness level of the scanned image which is the image of the scanning area (the area where the document reading unit 20 can read the image) R0 is as shown in FIG. 6A. Is assumed. That is, the scanned image shown in FIG. 6A includes an image of the region R1 having a relatively high brightness level and an image of the region R2 having a relatively low brightness level. The area R1 corresponds to a non-manuscript area which is an area where the document arranged on the platen 20a does not exist. The area R2 corresponds to the document area, which is the area where the document is arranged. The images of the plurality of originals arranged on the platen 20a correspond to the images of the region R2, which is the image of the original region (sometimes referred to as the original image).

In the process of specifying the document area (S4), the control unit 100 creates the histogram shown in FIG. 6B. This histogram is a histogram showing the distribution of the brightness level of each pixel in the scanned image. The brightness level is calculated by substituting the output value indicating the light receiving intensity of the light receiving sensors for each color of R (red), G (green), and B (blue) constituting the image sensor 20f into a predetermined formula. To.

A graph showing the brightness level existing in the scanned image is shown in FIG. 6 (c).

As is clear from the histogram shown in FIG. 6B and the graph shown in FIG. 6C, there are a plurality of maximum brightness levels in the scanned image. The highest brightness level LV1 among the maximum values of the plurality of brightness levels in the scanned image is the brightness level of the image in the region R1 which is the non-original region. The brightness level of the image in the region R1 corresponds to the brightness level of the lower surface (white plate) of the automatic document feeder 10. On the other hand, among the maximum values of the plurality of brightness levels in the scanned image, the brightness level LV2 other than the brightness level LV1 is the brightness level of the image in the region R2 which is the original region. A plurality of original documents exist in the region R2, and each of the plurality of original documents has different paper qualities (reflectance). Therefore, there are a plurality of brightness levels LV2 of the image in the region R2.

The control unit 100 detects the highest brightness level LV1 among the maximum values of the plurality of brightness levels in the created histogram as the brightness level of the image in the non-manuscript region. When the control unit 100 holds a known value as the brightness level of the image in the non-manuscript area, the control unit 100 may detect the value held as the brightness level of the image in the non-manuscript area.

Subsequently, the control unit 100 sets an arbitrary value between the second highest lightness level LV2a and the highest lightness level LV1 among the maximum values of the plurality of lightness levels in the created histogram (for example, the lightness level LV2a and the lightness level LV1). (Intermediate value) is set as the threshold TH, and among the maximum values of the plurality of brightness levels of the number of pixels in the histogram, a plurality of brightness levels LV2 lower than the threshold TH are detected as the brightness level of the image in the document region.

Next, as shown in FIG. 6D, the control unit 100 extracts an image region having a brightness level equal to or lower than the threshold value TH (that is, an image region R2 having a brightness level LV2) as a document region, and extracts the region (e). ), The contour of the extracted document region (that is, the contour LN of the region R2) is extracted.

The control unit 100 may binarize the scanned image according to the brightness level with reference to the threshold value TH, and extract a position where the amount of change in the scanned image after binarization is large as the outline of the document region.

FIG. 7 is a subroutine of the process (S4) for specifying the document area of FIG.

In the process of identifying the document area (S4) with reference to FIG. 7, the control unit 100 detects the brightness level (first background level) of the image in the non-original area in the scanned image (S401), and the document The brightness level (second background level) of the image of the region is detected (S403).

Following the process of step S403, the control unit 100 extracts the original area (S405) and extracts the outline of the original area based on the brightness level of the image in the non-original area and the brightness level of the image in the original area (S405). S407), return.

[Process to detect overlapping of originals]

FIG. 8 is a diagram illustrating a process (S5) of detecting the overlap of the documents of FIG.

In the process of detecting the overlap of documents (S5) with reference to FIG. 8, the control unit 100 extracts one closed area from the contour of the document area. One closed area is extracted in order to detect the presence or absence of overlapping of documents in each document area when a plurality of document areas are extracted. Since the contour LN of the region R2, which is the document region of the present embodiment, includes only one closed region, the contour LN itself is extracted here.

Next, the control unit 100 identifies the vertices in the extracted closed region in which the directions of the line segments constituting the vertices are orthogonal to each other. The contour LN includes eight vertices CR1, CR2, CR3, CR4, CR5, CR6, CR7, and CR8. Of these vertices, the vertices CR3 and CR7 are not orthogonal to each other in the directions of the line segments forming the vertices. Therefore, the vertices CR1, CR2, CR4, CR5, CR6, and CR8 are identified from the contour LN.

Next, the control unit 100 determines whether or not the specified vertices form a rectangle. Specifically, the control unit 100 determines that the specified vertices do not form a rectangle when the specified vertices are not four. Further, when the number of the specified vertices is 4, the control unit 100 sets the extension directions of the two line segments orthogonal to each other at the arbitrary vertices as the x-axis and the y-axis, respectively, and the coordinates (x) of each vertex. , Y) is calculated. Then, when there is no other vertex having the same x-coordinate as the x-coordinate of the vertex, or when there is no other vertex having the same y-coordinate as the y-coordinate of the vertex, the specified vertex Determines that does not form a rectangle. The control unit 100 identifies when there is another vertex having the same x-coordinate as the x-coordinate of the vertex and another vertex having the same y-coordinate as the y-coordinate of the vertex. Determine that the vertices form a rectangle.

When the control unit 100 determines that the specified vertices form a rectangle, the control unit 100 does not detect the occurrence of overlapping documents from the extracted closed area. On the other hand, when the control unit 100 determines that the specified vertices do not form a rectangle, the control unit 100 detects the occurrence of overlapping documents from the extracted closed region. Since the contour LN has eight specified vertices, it is determined that the specified vertices do not form a rectangle, and the occurrence of overlapping of documents is detected.

FIG. 9 is a subroutine of the process (S5) for detecting the overlap of the documents of FIG.

In the process of detecting the overlap of documents (S5) with reference to FIG. 9, the control unit 100 extracts one closed area from the contour of the document area (S501). Next, the control unit 100 identifies the vertices in the extracted closed region in which the directions of the line segments constituting the vertices are orthogonal to each other (S503). Next, the control unit 100 determines whether or not the specified vertices form a rectangle (S505).

If it is determined in step S505 that the specified vertices form a rectangle (YES in S505), the control unit 100 detects the overlap of documents from the extracted closed area (S507), and proceeds to the process of step S511.

If it is determined in step S505 that the specified vertices do not form a rectangle (NO in S505), the control unit 100 does not detect the overlap of the originals from the extracted closed area (S509), and proceeds to the process of step S511.

In step S511, the control unit 100 determines whether or not all the closed regions included in the contour of the document region have been extracted (S511).

If it is determined in step S511 that all the closed areas included in the contour of the document area have not been extracted (NO in S511), the control unit 100 proceeds to the process of step S501 and extracts the unextracted closed areas.

When it is determined in step S511 that all the closed areas included in the contour of the document area have been extracted (YES in S511), the control unit 100 returns.

[Process to identify the foreground image]

FIG. 10 is a diagram illustrating a process (S7) for specifying the foreground image of FIG.

In the process of identifying the foreground image (S7) with reference to FIG. 10, the control unit 100 extracts a closed region (here, contour LN) in which the originals overlap from the contour of the original region, and FIG. Create a histogram as shown in a). This histogram is a histogram showing the distribution of the brightness level of each pixel in the image of the closed region (here, each pixel in the image of the region R2).

As described above, there are a plurality of brightness levels of each pixel in the image of the region R2 which is the original region. Therefore, the histogram includes a plurality of (here, two) peaks P1 and P2. Here, as shown in FIG. 10B, in the region R2, the original of the image of the region R21 exists in the foreground, and a part of the original of the image of the region R22 overlaps the original of the region R21. It is assumed that The peak P1 is a peak according to the brightness level of each pixel in the image of the region R21. The peak P2 is a peak according to the brightness level of each pixel in the image of the region R22 shown in FIG. 10 (b). The brightness level of each pixel in the image of the area R21 and the brightness level of each pixel in the image of the area R22 due to the difference between the paper quality of the document existing in the area R21 and the paper quality of the document existing in the area R22. Are different from each other.

Next, the control unit 100 identifies a plurality of peaks P1 and P2 appearing in the histogram, and identifies the brightness level LV21 of any peak P1 among the peaks P1 and P2. Next, the control unit 100 identifies pixels having a brightness level (that is, pixels in the area R21) in a predetermined range including the brightness level LV21 (here, a range of the brightness level LV21A or more and the brightness level LV21B or less), and FIG. As shown in c), the specified pixel is excluded from the image of the region R2. As a result, the removed image becomes the image of the region R22.

Next, the control unit 100 identifies the vertex CR of the contour LN222 of the image of the region R22, which is the image after removal, and determines whether or not the specified vertex CR constitutes a rectangle. When it is determined that the specified vertices do not form a rectangle, the control unit 100 does not specify the removed image as the image of the foreground original, and does not save the removed image as the image of the foreground original. On the other hand, when it is determined that the specified vertices form a rectangle, the control unit 100 specifies the removed image as the image of the frontmost document, and saves the removed image as the image of the frontmost document. Here, the number of vertices CR identified from the contour LN222 of the image of the region R22 is 5, and does not form a rectangle. Therefore, the removed image is not specified as the image of the foreground original, and the image of the area R22 is not saved.

Next, the control unit 100 identifies the brightness level LV22 at another peak P2 among the plurality of peaks P1 and P2 in the histogram. Next, the control unit 100 identifies pixels having a brightness level in a predetermined range including the brightness level LV22 (here, a range of the brightness level LV22A or more and the brightness level LV22B or less) (that is, the pixels in the image of the area R22), and the figure As shown in 10 (d), the specified pixel is excluded from the image of the region R2. As a result, the removed image becomes the image of the region R21.

Next, the control unit 100 identifies the four vertices CR of the contour LN221 of the image of the region R21 which is the removed image, and determines that the specified vertices form a rectangle. The control unit 100 identifies the image of the region R21, which is the image after removal, as the image of the foreground original. In this case, the control unit 100 adds a line segment hidden in the image of the region R2 (a line segment constituting the contour LN221 that is not included in the contour LN) to the contour LN. The control unit 100 saves the image of the area R21 as the image of the foreground original.

FIG. 11 is a subroutine of the process (S7) for specifying the foreground image of FIG.

In the process of identifying the foreground image (S7) with reference to FIG. 11, the control unit 100 extracts from the contour of the document region the closed region in which the overlap of the documents is detected in step S507 of FIG. 9 (S701). , Create a histogram showing the distribution of the brightness level of each pixel in the extracted closed region image (S703). Next, the control unit 100 identifies the brightness level of the peak appearing in the created histogram (S705), and identifies pixels having a brightness level within a predetermined range including the specified brightness level (S707). Subsequently, the control unit 100 excludes the specified pixel from the extracted image of the closed region (S709), and specifies the apex of the contour of the removed image (S711). Next, the control unit 100 determines whether or not the specified vertices form a rectangle (S713).

When it is determined in step S713 that the specified vertices do not form a rectangle (NO in S713), the control unit 100 does not specify the removed image as the image of the foreground original (S7715), and all the images in the histogram. It is determined whether or not the peak has been specified (S717).

If it is determined in step S717 that all peaks in the histogram are not specified (NO in S717), the control unit 100 proceeds to the process of step S705 and specifies the brightness level of another peak appearing in the created histogram.

If it is determined in step S717 that all the peaks in the histogram have been identified (YES in S717), the control unit 100 proceeds to the process of step S723.

When it is determined in step S713 that the specified vertices form a rectangle (YES in S713), the control unit 100 identifies the removed image as the image of the foreground original (S719) and hides it in the original area. The line segment is added to the outline of the document area (S721), and the process proceeds to step S723.

In step S723, the control unit 100 determines whether or not all the closed regions where the overlap of the originals is detected in step S507 of FIG. 9 are extracted (S723).

When it is determined in step S723 that all the closed regions where the overlap of the originals is detected are not extracted (NO in S723), the control unit 100 proceeds to the process of step S701 and extracts another closed region.

When it is determined in step S723 that all the closed regions where the overlap of the originals is detected have been extracted (YES in S723), the control unit 100 returns.

The process of specifying the foreground image may be performed by the following method in addition to the case of being performed by the above method.

12 and 13 are diagrams for explaining a modified example of the process (S7) for specifying the foreground image of FIG.

In the process of identifying the foreground image (S7) with reference to FIG. 12A, the control unit 100 extracts one closed region from the contour of the document region. Here, the contour LN itself is extracted.

Next, the control unit 100 identifies the vertices in the extracted closed region. Eight vertices CR1, CR2, CR3, CR4, CR5, CR6, CR7, and CR8 are identified from the contour LN.

With reference to FIG. 12B, the control unit 100 subsequently identifies the vertices that are at right angles to the identified vertices. Here, the vertices CR1, CR2, CR4, CR5, CR6, and CR8 are identified.

Whether or not each of the eight vertices in the extracted closed region is a right angle is specified by using the filter (differential filter) FR1, FR2, FR3, and FR4 for detecting the document angle shown in FIG. 12 (c). May be good. The filter FR1 is a filter for detecting the upper left vertex of the rectangle. The filter FR2 is a filter for detecting the upper right vertex of the rectangle. The filter FR3 is a filter for detecting the lower left vertex of the rectangle. The filter FR4 is a filter for detecting the lower right vertex of the rectangle.

When the filter for detecting the document angle is used, the control unit 100 selects one of the eight vertices in the extracted closed region, and extends one of the two line segments constituting the selected vertex. The current direction is the x direction, and the direction perpendicular to the x direction (the extending direction of the other line segment) is the y direction. Next, the control unit 100 superimposes the positions of the selected vertex and the center of the filter FR1 in a state where the x direction of the selected vertex and the x direction of the filter FR1 are parallel to each other. Next, the control unit 100 calculates the differential value of the brightness level of each of the plurality of pixels near the selected vertices from the extracted image of the closed region, and superimposes each of the calculated differential values and each of the plurality of pixels. Multiply each numerical value of the filtered FR1 with each of them. Next, the control unit 100 calculates the total value of the values obtained by multiplication. When the total value exceeds a predetermined threshold value, the control unit 100 determines that the selected vertices are at right angles to the upper left of the rectangle. Since the amount of change in the brightness level is large near the contour LN of the extracted closed region image, when the selected vertex is the upper left vertex of the rectangle, each of the two line segments constituting the vertex and the filter FR1 “ The arrangement direction of the numbers of "1" matches, and the calculated total value exceeds the threshold value.

The control unit 100 determines whether or not the selected vertices are at right angles by performing the same calculation for each pair of the selected vertices and the filters FR2, FR3, and FR4.

With reference to FIG. 13A, the control unit 100 then estimates a plurality of vertices and line segments hidden in the extracted closed region based on the coordinates of the identified vertices at right angles. The "hidden vertices and line segments" mean the vertices and line segments that constitute the contour of the document in which overlap occurs, and are not included in the contour of the document area.

Specifically, the control unit 100 extracts two vertices A and B from the specified right-angled vertices, and sets the extending direction of the line segment connecting the extracted two vertices A and B in the x direction and x. The direction perpendicular to the direction is defined as the y direction. Next, the control unit 100 determines whether or not another vertex exists on a line segment extending in the y direction from each of the two extracted vertices A and B. The control unit 100 makes the above determination for all combinations of the two vertices. The control unit 100 has another vertex C on a line segment extending in the y direction from one vertex A of the two extracted vertices, and the other vertex B of the two extracted vertices is in the y direction. If there are no other vertices on the extending line segment, specify the combination of vertices A and B, and assume a rectangle composed of the specified combination of vertices A and B and other vertices C. The remaining one vertex in the assumed rectangle is estimated as a hidden vertex D. Further, the hidden line segment is estimated based on the hidden vertex D and the assumed rectangle.

Here, the vertex CR11 and the line segments LN11 and LN12 are estimated based on the coordinates of the vertices CR5 and CR6 (in this case, the vertex CR5 corresponds to the vertex A, the vertex CR6 corresponds to the vertex B, and the vertex CR4 corresponds to the vertex C). Further, the vertices CR21 and the line segments LN21 and LN22 are estimated based on the coordinates of the vertices CR1 and CR2 (in this case, the vertex CR1 corresponds to the vertex A, the vertex CR2 corresponds to the vertex B, and the vertex CR8 Corresponds to the above vertex C).

With reference to FIG. 13 (b), the control unit 100 then determines the brightness level of the image of the region R2 at each position of the estimated line segments LN11 and LN12, and the line segments LN21 and LN22. From the estimated line segments LN11 and LN12, and the line segments LN21 and LN22, the line segment constituting the outline of the frontmost document is specified.

Specifically, the control unit 100 sets each of the estimated line segments LN11 and LN12 in a direction perpendicular to the extending direction of the line segment (directions indicated by middle arrows AR11 and AR12 in FIG. 13B, respectively). The presence or absence of an edge, which is a position where the brightness level changes in the image of the region R2 along the line, is detected. Based on the edge detection result, the control unit 100 determines whether or not the estimated line segments LN11 and LN12 are specified as the line segments constituting the contour of the frontmost document.

Similarly, with reference to FIG. 13 (c), the control unit 100 determines each of the estimated line segments LN21 and LN22 in a direction perpendicular to the extending direction of the line segment (middle arrow in FIG. The presence or absence of an edge, which is a position where the brightness level changes in the image of the region R2 along the direction indicated by AR21 and AR22) is detected. Based on the edge detection result, the control unit 100 determines whether or not to specify the estimated line segments LN21 and LN22 as the line segments constituting the contour of the frontmost document.

The edge may be specified by using the filter (differential filter) FR11 and FR12 for edge detection shown in FIG. 13D. The filter FR11 is a filter for detecting an edge in the x direction when the estimated extension direction of the line segment is the y direction (in the case of the line segments LN12 and LN22). The filter FR12 is a filter for detecting an edge in the y direction when the estimated extension direction of the line segment is the x direction (in the case of the line segments LN11 and LN21).

Specifically, the control unit 100 selects one of the estimated line segments (a line segment extending in a direction close to the horizontal direction, in this case, a line segment LN11 or LN21), and the selected line segment. The extending direction is the x direction, and the direction perpendicular to the extending direction of the selected line segment is the y direction. Next, the control unit 100 superimposes the filter FR11 near the selected line segment in a state where the x direction of the selected line segment and the x direction of the filter FR11 are parallel to each other. Next, the control unit 100 calculates the differential value of the brightness level of each of the plurality of pixels in the vicinity of the selected line segment in the region R2, and each of the calculated differential values and the filter superimposed on each of the plurality of pixels. Multiply each value of FR11 with each of them. Next, the control unit 100 calculates the total value of the values obtained by multiplication. The control unit 100 calculates the total value each time while moving the filter FR11 in the y direction, and when the calculated total value exceeds a predetermined threshold value, extends parallel to the extending direction of the selected line segment. Detect existing edges.

Similarly, the control unit 100 selects one of the estimated line segments (a line segment extending in a direction close to the vertical direction, in this case, a line segment LN12 or LN22), and extends the selected line segment. Let the direction be the y direction and the direction perpendicular to the extending direction of the selected line segment be the x direction. Next, the control unit 100 superimposes the filter FR12 near the selected line segment in a state where the y direction of the selected line segment and the y direction of the filter FR12 are parallel to each other. Next, the control unit 100 calculates the differential value of the brightness level of each of the plurality of pixels in the vicinity of the selected line segment in the region R2, and each of the calculated differential values and the filter superimposed on each of the plurality of pixels. Multiply each value of FR12 by each value. Next, the control unit 100 calculates the total value of the values obtained by multiplication. The control unit 100 calculates the total value each time while moving the filter FR12 in the x direction, and when the calculated total value exceeds a predetermined threshold value, extends parallel to the extending direction of the selected line segment. Detect existing edges.

FIG. 14 is a diagram showing the relationship between the edge detection result and the specified foreground image in the modified example of the process (S7) for specifying the foreground image of FIG.

With reference to FIGS. 13 and 14, the control unit 100 subsequently adds a specified line segment to the contour of the document area as a line segment constituting the contour of the frontmost document, and is defined by the specified line segment. The image in the rectangular area is specified as the image of the foreground original.

In FIG. 14A, an edge extending parallel to the extending direction (x direction) of the line segment LN11 is detected, and extends parallel to the extending direction (y direction) of the line segment LN12. The existing edge has been detected. On the other hand, an edge extending parallel to the extending direction (x direction) of the line segment LN21 is not detected, and an edge extending parallel to the extending direction (y direction) of the line segment LN22 is detected. Not detected. In this case, the control unit 100 specifies the line segments LN11 and LN12 as the line segments constituting the contour of the frontmost document. As shown in FIG. 14B, the control unit 100 identifies the image of the rectangular region R22 defined by the specified line segments LN11 and LN12 as the image of the foreground original, and the specified line segment LN11 and LN12 is added to the contour of the document area.

The control unit 100 displays on the screen displayed in the process (S9) of notifying the occurrence of overlapping of the originals by saving the line segments LN21 and LN22 different from the specified line segments in association with the image of the original area. , The line segments LN21 and LN22 may be displayed as the outline of the document to be rearranged.

In FIG. 14C, an edge extending parallel to the extending direction (x direction) of the line segment LN21 is detected, and extends parallel to the extending direction (y direction) of the line segment LN22. The existing edge has been detected. On the other hand, an edge extending parallel to the extending direction (x direction) of the line segment LN11 is not detected, and an edge extending parallel to the extending direction (y direction) of the line segment LN12 is detected. Not detected. In this case, the control unit 100 specifies the line segments LN21 and LN22 as the line segments constituting the contour of the foreground document. As shown in FIG. 14D, the control unit 100 identifies the image of the rectangular region R21 defined by the specified line segment LN21 and LN22 as the image of the foreground original, and the specified line segment LN21 and LN22 is added to the contour of the document area.

The control unit 100 displays on the screen displayed in the process (S9) of notifying the occurrence of overlapping of the originals by saving the line segments LN11 and LN12 different from the specified line segments in association with the image of the original area. , The line segments LN11 and LN12 may be displayed as the outline of the document to be rearranged.

FIG. 15 is a subroutine of a modified example of the process (S7) for specifying the foreground image of FIG.

In the process of identifying the foreground image (S7) with reference to FIG. 15, the control unit 100 extracts from the contour of the document region the closed region in which the overlap of the documents is detected in step S507 of FIG. 9 (S751). , The vertices in the extracted closed region are specified (S753). Next, the control unit 100 identifies vertices that are right-angled among the specified vertices (S755), and estimates hidden vertices and line segments in the extracted closed region based on the coordinates of the identified vertices that are right-angled. (S757). Subsequently, the control unit 100 identifies the line segment constituting the contour of the foreground document from the estimated line segment based on the change in the brightness level of the image at each position of the estimated line segment (S759). ). Subsequently, the control unit 100 adds a line segment specified as a line segment constituting the contour of the frontmost document to the contour of the document area (S761), and obtains an image of a rectangular area defined by the specified line segment. It is specified as an image of the front document (S763).

Following the process of step S763, the control unit 100 determines whether or not all the closed regions where the overlap of the originals is detected in step S507 of FIG. 9 are extracted (S765).

When it is determined in step S765 that all the closed regions where the overlap of the originals is detected are not extracted (NO in S765), the control unit 100 proceeds to the process of step S751 and extracts another closed region.

When it is determined in step S765 that all the closed regions where the overlap of the originals is detected have been extracted (YES in S765), the control unit 100 returns.

[Process to notify the occurrence of overlapping of originals]

FIG. 16 is a diagram illustrating a process (S9) of notifying the occurrence of overlapping of the documents of FIG. FIG. 17 is a diagram schematically showing a screen displayed on the operation panel 70 in the process (S9) of notifying the occurrence of overlapping of the documents of FIG. Note that FIG. 16 shows the processing when the image of the rectangular region R22 (FIG. 14 (b)) defined by the specified line segments LN11 and LN12 is specified as the image of the foreground original.

In the process (S9) of notifying the occurrence of overlapping of documents with reference to FIG. 16, the control unit 100 identifies the image of the area R2, which is the document area, and the image, as shown in FIG. 16A. The contour LN1 of the region R2 obtained in the process (S7) (the contour LN plus the line segments LN11 and LN12) is acquired. The area R2 includes an image of the area R22 which is an image of the frontmost document and an image of the area R21 which is an image of a document other than the frontmost document.

Next, as shown in FIG. 16B, the control unit 100 inverts the image of the region R2, which is the original image, with the sub-scanning direction (or the main scanning direction) as the reference line. As a result, the planar positional relationship between the documents arranged in the area R21 and the documents arranged in the area R22 is the planar positional relationship when the user views these documents from above the platen 20a. Is equal to. Then, the control unit 100 identifies the image of the foreground document (image of the area R22) as the original to be removed in the inverted original image, and the image other than the image of the foreground document (image of the area R21). ) Is specified as the manuscript to be rearranged.

Next, the control unit 100 specifies the position of the document to be removed with respect to the position of the document to be rearranged. As shown in FIG. 16 (c), the identification includes the distribution of the main scanning direction and the sub-scanning direction of the pixels constituting the image of the region R21, and the main scanning direction and the sub-scanning direction of the pixels constituting the image of the region R22. It is preferably performed based on the distribution of. Here, the pixels constituting the image in the area R22 are present on the minus side (right side) in the main scanning direction as compared with the pixels forming the image in the area R21, and are present on the minus side (lower side) in the sub-scanning direction. ) Exists. Therefore, it is specified that the document to be removed is located on the lower right side of the document to be rearranged.

Subsequently, the control unit 100 notifies the removal and rearrangement of the original. As shown in FIG. 17A, the control unit 100 notifies the user that the documents are overlapped with each other, and displays a screen on the operation panel 70 asking the user whether or not to rearrange the documents. To do. When the "No" key KY1 is pressed on the screen shown in FIG. 17A, the control unit 100 ends the process.

When the "Yes" key KY2 is pressed on the screen of FIG. 17A, the control unit 100 displays on the operation panel 70 a screen requesting the removal of the original to be removed and the rearrangement of the original to be rearranged. To do. The screen shown in FIG. 17B shows the position of the original to be removed, removes the original to be removed, rearranges the original to be rearranged, and re-instructs the execution of image scanning. Is to notify.

It is preferable that the original to be removed and the original to be rearranged in the original image are displayed in different modes from each other. Here, a preview image showing the outlines of a plurality of originals arranged on the platen 20a is displayed, and a character string indicating that the original is to be removed is attached to the area of the original to be removed, and the original to be rearranged. A character string indicating that it is a target for relocation is attached to the area of. Further, the image and contour of the original to be removed are colored differently from the image and contour of the original to be rearranged. As a result, the manuscript to be removed can be notified to the user in an easy-to-understand manner.

Further, when the "Yes" key KY2 is pressed on the screen of FIG. 17 (a), the control unit 100 may display the screen shown in FIG. 17 (c) instead of the screen shown in FIG. 17 (b). Good. The screen shown in FIG. 17C is a screen for explaining the position of the document to be removed in characters and notifying that the document to be removed is to be removed and that the image reading execution instruction is to be performed again.

The user who receives the above notification and rearranges the originals removes the frontmost original (the image of the frontmost original is already saved in the process of step S8 of FIG. 5) from the platen 20a. By rearranging the documents other than the foreground document on the platen 20a and pressing the "confirmation" key KY3 on the screen shown in FIG. 17 (b) or FIG. 17 (c), an instruction to re-execute the image reading is given. Do. When the image is read again, the frontmost document in the first image reading is removed, and the empty space in the scanning area R0 becomes wide, so that the documents are less likely to overlap each other.

"Rearranging the original" means placing the original on the platen for re-reading the image, and it is not essential to remove the original from the platen and then reposition it on the platen. Absent. The position of the rearranged original may or may not be changed.

In the process (S9) of notifying the occurrence of overlapping of documents, the control unit 100 removes the documents to be removed without explaining the position of the documents to be removed, and re-instructs the execution of image reading. You may notify us of what to do. In this case, the user identifies the document to be removed by visually observing the arrangement state of the plurality of documents on the platen 20a.

FIG. 18 is a subroutine of the process (S9) for notifying the occurrence of overlapping of the documents of FIG.

With reference to FIG. 18, in the process (S9) of notifying the occurrence of overlapping of the originals, the control unit 100 acquires the original image and its outline (S901), and the originals with the main scanning direction or the sub-scanning direction as the reference line. The image is inverted (S903). Next, the control unit 100 identifies the foreground original as the original to be removed (S905), and identifies the original other than the foremost original as the original to be rearranged (S907). Next, the control unit 100 specifies the position of the document to be removed with respect to the position of the document to be rearranged (S909), and displays a screen for notifying the occurrence of overlapping of the documents (S911). Next, the control unit 100 determines whether or not the image reading execution instruction has been received (S913).

If it is determined in step S913 that the image reading execution instruction has been received (YES in S913), the control unit 100 proceeds to the process of step S3 of FIG. 5 and reads the original image again.

If it is determined in step S913 that the image reading execution instruction is not accepted (NO in S913), the control unit 100 ends the process.

[Effect of Embodiment]

FIG. 19 is a diagram illustrating the effect of one embodiment of the present invention.

With reference to FIG. 19, in the present embodiment, after the user places a plurality of documents MS1 and MS2 on the platen 20a (FIG. 19 (a)), the documents are overlapped with each other as shown in FIG. 19 (b). When (the portion shown by the middle region OP in FIG. 19B) occurs, the image of the frontmost document MS1 which is the document closest to the platen is specified. Then, the image of the frontmost document MS1 is saved, the removal of the frontmost document MS1 is requested, and the rearrangement of the document MS2 other than the frontmost document is required. In response to this request, the user removes the foremost original MS1 (FIG. 19 (c)) and gives an instruction to execute image reading again for only the remaining original MS2 (FIG. 19 (d)). By removing the frontmost document MS1, the empty space in the reading area R0 becomes wider, so that the document MS2 after removal is less likely to overlap. As a result, it is possible to eliminate the trouble of rearrangement and rescanning that may occur when scanning images of a plurality of original documents. As a result, the loss of the scanning time of the original image can be reduced, the work efficiency can be improved, and the convenience can be improved.

[Other]

The processing in the above-described embodiment may be performed by software or by using a hardware circuit. It is also possible to provide a program that executes the processing according to the above-described embodiment, and record the program on a recording medium such as a CD-ROM, a flexible disk, a hard disk, a ROM, a RAM, or a memory card and provide the program to the user. You may decide to do it. The program is executed by a computer such as a CPU. Further, the program may be downloaded to the device via a communication line such as the Internet.

It should be considered that the above embodiments are exemplary in all respects and not restrictive. The scope of the present invention is shown by the scope of claims rather than the above description, and it is intended to include all modifications within the meaning and scope equivalent to the scope of claims.

1 MFP (Multifunction Peripheral)
10 Automatic document feeder (example of document holder)
11 Document set sensor 12 Document paper feed tray 13 Document output tray 20 Document reader (example of acquisition means)
20a, 1020a Platen (an example of platen)
20b IR module 20c Drive transmission unit 20d IR motor 20e lamp 20f Image sensor 21 Device lifting sensor 30 Image forming unit 31a, 31b, 31c, 31d Photoreceptor drum 32a, 32b, 32c, 32d Exposure scanning unit 33 Transfer belt 34 Front door sensor 35 Image formation position 40 Automatic double-sided unit 50 Paper feed section 51, 53, 61, 63 Paper cassette 52, 54, 62, 64 Pickup roller 60 Paper feed cabinet 70 Operation panel (example of reception means)
71 Display unit 72 Touch panel input unit 73 Key input unit 80 Secondary power switch 90 Facsimile unit 91 Communication interface unit 100 Control unit 101 CPU (Central Processing Unit)
102 ROM (Read Only Memory)
103 RAM (Random Access Memory)
111 Original area specifying part (an example of document area specifying means)
112 Overlap detection unit (an example of overlap detection means)
113 Foreground image identification part (an example of foreground identification means)
114 Foreground image storage unit (example of storage means)
115 Relocation notification unit (example of requesting means)
120 HDD (Hard Disk Drive)
1010 Document holder 1010a Hinge A, B, C, CR, CR1, CR3, CR4, CR5, CR6, CR7, CR8, CR11, CR21, D Vertex FR1, FR2, FR3, FR4, FR11, FR12 Filter KY1, KY2, KY3 Keys LN, LN1, LN221, LN222 Contours LN11, LN12, LN21, LN22 Line segments LV1, LV2, LV2a, L21, LV21A, LV21B, LV22, LV22A, LV22B Brightness level MS, MS1, MS2 Manuscripts overlap Area R0 Reading area R1, R2, R21, R22 area

Claims (12)

An acquisition means for acquiring a scanned image including images of a plurality of originals arranged on a platen, and
An overlap detecting means for detecting the presence or absence of overlap between documents based on the scanned image, and
When the overlap of the originals is detected by the overlap detecting means, the frontmost specifying means for specifying the image of the foremost original, which is the original closest to the platen among the plurality of overlapping originals. ,
A storage means for storing the image of the foreground original, and
It is provided with a requesting means for requesting the removal of the frontmost original among the plurality of overlapping originals and requesting the rearrangement of the originals other than the frontmost original among the plurality of overlapping originals. Also, an image reader. Further provided with a reception means for accepting a setting indicating that a plurality of documents are arranged on the platen.
The image reading device according to claim 1, wherein when the receiving means receives the setting, the overlapping detecting means detects the presence or absence of overlapping of documents. Based on the distribution of brightness levels in the scanned image, a document area specifying means for specifying a document area in the scanned image, which is an area in which a plurality of documents arranged on the platen exist. Further prepare
The image reading device according to claim 1 or 2, wherein the overlap detecting means detects the presence or absence of overlap between documents based on an image in the document area. The overlap detecting means is
A first vertex identifying means for identifying vertices whose line segments are orthogonal to each other from the contour of the document region,
3. The third aspect of the present invention includes a vertex detecting means for detecting the presence or absence of overlapping of documents in the original document area based on whether or not the vertices specified by the first vertex specifying means form a rectangle. The image reader described. The foreground identification means
Exclusion means for excluding pixels having a brightness level within the first range of the image of the original area from the image of the original area, and
A second vertex identification means for identifying vertices from the contour of a new image after exclusion by the exclusion means, and
When the vertices specified by the second vertex specifying means form a rectangle, the first foreground determination means for determining that the new image is the image of the foreground original.
3. The third aspect of the present invention includes a second frontmost determination means for determining that the new image is not an image of the frontmost original when the vertices specified by the second vertex identification means do not form a rectangle. Or the image reading device according to 4. The exclusion means
A peak identification means for specifying a peak brightness level among a plurality of brightness levels of the image in the document area, and
The image reading apparatus according to claim 5, further comprising a pixel exclusion means for excluding pixels having a brightness level within the first range including the brightness level specified by the peak specifying means from the image in the original area. The foreground identification means
A third vertex identifying means for identifying vertices at right angles to the contour of the document region,
A plurality of vertices and line segments constituting the contour of the document in which overlap occurs based on the coordinates of the vertices specified by the third vertex specifying means, and are not included in the contour of the document area. An estimation method for estimating the vertices and line segments of
Based on the change in the brightness level of the image in the document region at each position of the plurality of line segments estimated by the estimation means, the foreground document from the plurality of line segments estimated by the estimation means. Line segment identification means for identifying the line segments that compose the outline of
The image reading device according to claim 3 or 4, which includes an image specifying means for specifying an image of a rectangular region defined by a line segment specified by the line segment specifying means as an image of the frontmost original. The line segment identification means
For each of the plurality of line segments estimated by the estimation means, the presence or absence of an edge at a position where the brightness level changes in the image of the document region along the direction perpendicular to the extending direction of the line segment is detected. Edge detection means and
Based on the detection results of the edge detection means for each of the plurality of line segments estimated by the estimation means, the contour of the frontmost document is formed from the plurality of line segments estimated by the estimation means. The image reading device according to claim 7, further comprising an edge identifying means for identifying a line segment. The requesting means
A reversing means for reversing an image in the original area with the main scanning direction or the sub-scanning direction as a reference line, and
In the image after being inverted by the inversion means, the image of the foreground original is specified as the original to be removed, and the image other than the image of the foreground original after being inverted by the inversion means is specified. Relocation identification means to specify as the original to be rearranged, and
The image reading apparatus according to any one of claims 3 to 8, further comprising a rearrangement requesting means for requesting removal of the original to be removed and rearrangement of the original to be rearranged. The rearrangement requesting means displays the manuscript to be removed and the manuscript to be rearranged in the image of the manuscript area after being inverted by the reversing means in different modes from each other, thereby displaying the manuscript to be removed. 9. The image reading apparatus according to claim 9, which requests the removal of the original and the rearrangement of the original to be rearranged. One of claims 1 to 10, further comprising a document retainer that is rotatable about a hinge and is capable of taking an open state that exposes the platen and a closed state that covers the platen. The image reader described. The acquisition step of acquiring a scanned image including images of a plurality of originals arranged on a platen, and
An overlap detection step for detecting overlap between documents based on the scanned image, and
When the overlap between the originals is detected in the overlap detection step, the frontmost identification step for specifying the image of the foremost original, which is the original closest to the platen among the plurality of overlapping originals. ,
A save step to save the image of the foreground original,
A computer performs a request step of requesting the removal of the frontmost document among a plurality of overlapping originals and requesting the rearrangement of a document other than the frontmost original among a plurality of overlapping originals. The control program of the image reader to be executed by.

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