Image processing apparatus, control method of the image processing apparatus, and program

Abstract

To provide a mechanism capable of suppressing disappearance of a correction mark when an electronic document is generated from a document.SOLUTION: A MFP 101 includes: a scanner part 201 that reads a document and acquires a read image data; a data processing part 216 that converts a color of a pixel having a brightness equal to or higher than a threshold value in the read image data into white; and an operation part 203 that can perform at least a user operation related to the scanner part 201 and a user operation related to the data processing part 216. When determining that a first predetermined operation has been performed on an operation part 203, a CPU 205 of the MFP 101 sets a reading mode of the scanner part 201 to a second reading mode in which the document is read under a darker condition than a first reading mode, sets the threshold value of the data processing part 216 to a second threshold value larger than a first threshold value, and disables the change of the second reading mode and the change of the second threshold value.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to an image processing device, a control method for an image processing device, and a program. [Background technology]

[0002] Document scanners are commonly used to generate digitized documents (hereinafter referred to as "electronic documents") by optically scanning a paper document and receiving reflected light with a light-receiving element. Single-function scanners and scanner units built into multifunction peripherals can also be used as document scanners. Hereinafter, these devices will be collectively referred to as "reading devices." When a reading device digitizes a paper document with a low-density, achromatic (close to white) background, it may perform background removal processing to whiten the background above a certain brightness level. This background removal processing enhances the contrast between the background and text, eliminating variations in the read signal due to unevenness of the paper background, improving the appearance of the electronic document. Furthermore, when compressing the data of an electronic document, signal variations in the background, which occupies the majority of the paper area, are corrected to white, improving compression efficiency.

[0003] Incidentally, until now, only paper documents related to tax matters were recognized as originals, but with the recent advances in electronic document technology, legal reforms have made it possible for electronic documents to be recognized as originals if they meet certain conditions. For example, the Electronic Bookkeeping Act (hereinafter referred to as the "Electronic Bookkeeping Act") stipulates that, when a manuscript is converted into an electronic document, the white of the gradation pattern must not become completely white on the electronic document, and information such as corrections must not be lost (visibility must be maintained).

[0004] However, when the above-mentioned background removal process is performed, the condition that information such as corrections is not lost (hereinafter also referred to as the "condition for retaining corrections") may not be met. For example, if the brightness of the corrections is higher than the brightness of the threshold used as the boundary when the background removal process changes a specific pixel to white, the corrections will become completely white on the electronic document due to the background removal process, and the condition for retaining corrections in the electronic document method will not be met. Therefore, Patent Document 1 discloses a technology that does not perform the background removal process in order to represent corrections and the like in the scanned image.

[0005] However, simply disabling background removal processing may result in corrected areas appearing completely white on the electronic document, depending on the reading gradation characteristics of the reading device. To address this issue, Patent Document 2 proposes a technology that reduces the amount of light irradiated when reading a document, reading the document darkly (hereinafter, this reading method will be referred to as "dark reading"), thereby controlling the paper background so that it does not appear completely white on the electronic document. Furthermore, there are also products that provide a setting that allows the acquisition of electronic documents such as tax-related forms, and that, when the user selects this setting, perform dark reading without performing background removal processing. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-201827 [Patent Document 2] Japanese Patent Application Laid-Open No. 2006-295307 Summary of the Invention [Problem to be solved by the invention]

[0007] However, even if the settings are set to perform the above-mentioned blind reading and not to perform background removal, the user may later change either setting by mistake, or one of the settings may be changed in conjunction with the setting of another function. In this case, the condition for retaining corrections under the Electronic Bookkeeping Act is not met, and an electronic document different from the user's desire may be generated.

[0008] The present invention has been made in view of the above-mentioned problems, and has an object to provide a mechanism that can prevent correction traces from being lost when generating an electronic document from a manuscript. [Means for solving the problem]

[0009] In order to achieve the above-mentioned object, the image processing device of the present invention is an image processing device having a reading means for reading a document and obtaining read image data, an adjustment means for converting the color of pixels in the read image data that have a brightness greater than a threshold to white, and an operation means capable of performing at least user operations on the reading means and user operations on the adjustment means, and is characterized by comprising: a first determination means for determining whether a first predetermined operation has been performed on the operation means; a reading mode setting means for, when the first determination means determines that the first predetermined operation has been performed on the operation means, setting the reading mode of the reading means to a second reading mode that reads the document under darker conditions than the first reading mode; a threshold setting means for, when the first determination means determines that the first predetermined operation has been performed on the operation means, setting the threshold of the adjustment means to a second threshold that is greater than the first threshold; and a change disabling means for disabling the second reading mode set by the reading mode setting means and the second threshold set by the threshold setting means from being changed. [Effects of the Invention]

[0010] According to the present invention, it is possible to prevent traces of corrections from being lost when generating an electronic document from a manuscript. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a schematic diagram showing a system configuration related to a multifunction peripheral (hereinafter referred to as "MFP") according to the present invention. [Figure 2] FIG. 2 is a block diagram showing a detailed configuration of an MFP. [Figure 3] FIG. 10 is a sequence diagram showing the overall processing flow of the scan system in the MFP. [Figure 4] 10A and 10B are diagrams showing an example of a receipt read in normal reading mode or dark reading mode. [Figure 5] 10A and 10B are diagrams for explaining the relationship between background removal levels and background removal processing. [Figure 6] 3A to 3C are diagrams illustrating examples of setting UI screens displayed on an operation unit according to the first embodiment. [Figure 7] 10 is a flowchart showing the process from when an electronic document storage mode is selected to when a UI operation restriction is implemented in the first embodiment. [Figure 8] FIG. 10 is a diagram showing an example of a scan setting UI screen when a restriction on UI operations is being performed on the operation unit according to the first embodiment. [Figure 9] 10A to 10C are diagrams illustrating examples of setting UI screens displayed on an operation unit according to the second embodiment. [Figure 10] 10 is a flowchart from when a correction mark disappearance prevention button is pressed until a UI operation restriction is implemented in the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0012] Each embodiment of the present invention will be described in detail below with reference to the drawings. However, the configurations described in each of the following embodiments are merely examples, and the scope of the present invention is not limited to the configurations described in each embodiment. For example, each component constituting the present invention can be replaced with any configuration that can perform the same function. Also, any component may be added. Furthermore, any two or more configurations (features) of each embodiment can be combined.

[0013] First Embodiment The first embodiment will be described below with reference to FIGS.

[0014] [Overall system configuration] FIG. 1 is a schematic diagram showing a system configuration related to an MFP 101. As shown in FIG. 1, the MFP 101 is connected to a PC 102 via a network 103. A user can configure various settings using an operation unit (203 in FIG. 2, which will be described later) included in the MFP 101. Specifically, the user can configure various settings, such as the resolution and compression rate of image data, the data format (e.g., JPEG, TIFF, PDF, few-color compression, few-color compression (with OCR results), e-Document mode), and the transmission destination. The MFP 101 generates image data using software or hardware functions based on the various settings configured by the user and transmits the generated image data to a destination (e.g., the PC 102). Note that the image data transmitted to the PC 102 is transmitted in a file format such as PDF, and therefore can be viewed using a general-purpose viewer included in the PC 102.

[0015] [MFP detailed configuration] FIG. 2 is a block diagram showing a detailed configuration of the MFP 101. The MFP 101 (image processing device) has a scanner unit 201 (reading means), a printer unit 202, an operation unit 203 (operation means), and a control unit 204. The scanner unit 201 is an image input device. The printer unit 202 is an image output device. The operation unit 203 is a user interface (UI) such as a touch panel. Therefore, a user can perform UI operations on the UI screen of the operation unit 203. The scanner unit 201, printer unit 202, and operation unit 203 are connected to the control unit 204. The control unit 204 is further connected to the network 103 to input and output image information and device information.

[0016] The control unit 204 has a CPU 205, RAM 206, an operation unit I / F 207, a network I / F 208, a ROM 209, a storage unit 210, and a system bus 211. The control unit 204 further has an image bus interface 212, an image bus 213, a RIP unit 214, a device I / F unit 215, and a data processing unit 216. RIP is an abbreviation for Ruster Image Processor. The CPU 205 is a processor that controls the entire MFP 101. The RAM 206 is a work memory for the operation of the CPU 205, and also serves as an image memory for temporarily storing image data.

[0017] The operation unit I / F 207 is an interface with the operation unit 203, and outputs image data to be displayed on the operation unit 203 to the operation unit 203. The operation unit I / F 207 also outputs information that a user of the MFP 101 inputs by operating the UI on the operation unit 203 to the CPU 205. The network I / F 208 connects the MFP 101 to the network 103 and inputs and outputs information in packet format. The ROM 209 is a boot ROM and stores programs such as a boot program. The storage unit 210 is a hard disk drive and stores control software, image data, and the like. The CPU 205, RAM 206, operation unit I / F 207, network I / F 208, ROM 209, and storage unit 210 are connected to one another via a system bus 211.

[0018] The image bus interface 212 is a bus bridge that connects the system bus 211 and the image bus 213 and converts data structures. The image bus 213 transfers image data at high speed and is configured, for example, by a PCI bus or IEEE 1394. The image bus 213 is connected to a RIP unit 214, a device I / F unit 215, and a data processing unit 216. The RIP unit 214 analyzes the PDL (Page Description Language) code of print data received from the PC 102 or the like and develops it into a bitmap image with a set resolution, which is known as rendering processing. The device I / F unit 215 is connected to the scanner unit 201, which is an image input device, via a signal line 217, and to the printer unit 202, which is an image output device, via a signal line 218.

[0019] The data processing unit 216 performs image processing of image data input from the scanner unit 201 (hereinafter referred to as "scan data") and data processing of print images output to the printer unit 202, as well as processing such as few-color compression and OCR. Furthermore, the data processing unit 216 generates image data that satisfies the conditions for retaining correction marks under the Electronic Bookkeeping Act, i.e., an electronic document, as will be described later. The generated electronic document is transmitted to a set destination (e.g., PC 102) via the network I / F 208 and the network 103. Note that the MFP 101 described with reference to FIG. 2 is merely an example, and may have components not shown, or may lack some of the components shown, as necessary.

[0020] [Processing flow of the entire scanning system in the MFP] FIG. 3 is a sequence diagram showing the overall processing flow of the scan system in MFP 101. Each step in FIG. 3 is realized by CPU 205 in MFP 101 reading a program stored in storage unit 210 into RAM 206 and executing it. First, in step S301, CPU 205 accepts a UI operation from the user via operation unit 203. This allows the user to configure scan settings using operation unit 203. The scan settings allow multiple settings, such as color selection, scanning magnification, document type, scanning mode, and background removal level. Details of the scan settings will be described later in "Scan Settings and UI Operations."

[0021] In steps S302 and S303, the CPU 205 receives, via the operation unit I / F 207, button press information when the user operates the UI on the operation unit 203. At this time, the CPU 205 stores each value of the scan setting in the RAM 209 based on the received button press information. Note that the CPU 205 continues to accept UI operations from the user via the operation unit 203 until the start button (606 in FIG. 6, which will be described later) is pressed. Then, when the CPU 205 receives start button press information via the operation unit I / F 207, the process proceeds to step S304.

[0022] In step S304, CPU 205 transmits a command to scanner unit 201 to execute scanning. At this time, CPU 205 simultaneously transmits to scanner unit 201, among the scan setting values, information necessary for scanner unit 201 to execute scanning (hereinafter referred to as "scanner information"). Note that the scanner information also includes information such as the reading mode set by the user through a UI operation in step S301. In step S305, CPU 205 generates scan data by causing scanner unit 201 to scan the document based on the scanner information.

[0023] In step S306, CPU 205 causes scanner unit 201 to transmit the scan data generated in step S305 to data processing unit 216. In step S307, CPU 205 receives a notification from scanner unit 201 that the scan processing has ended. In step S308, CPU 205 transmits a command to data processing unit 216 to execute image processing of the scan data. At this time, CPU 205 simultaneously transmits to data processing unit 216 information (hereinafter referred to as "scan information") necessary for data processing unit 216 to execute image processing of the scan data, among the scan setting values. Note that the scan information also includes information such as the background removal level set by the user via UI operation in step S301.

[0024] In step S309, CPU 205 processes the scan data (read image data) received from scanner unit 201 using data processing unit 216 based on the scan information received from CPU 205. Note that CPU 205 also performs background removal processing using data processing unit 216 (adjustment means) in step S309. In step S310, CPU 205 receives a notification from data processing unit 216 that data processing has ended. This concludes the description of the sequence showing the flow of processing in the entire scan system of MFP 101.

[0025] [Scan Settings and UI Operation] As described above, the scan settings allow for multiple settings such as color selection, scanning magnification, document type, scanning mode, and background removal level. Color selection is a setting item related to color / monochrome when saving and copying scanned data. Scanning magnification is a setting item related to enlarging / reducing scanned data. Document type is a setting item related to the type of document to be scanned. The scanning mode is a setting item related to the amount of light irradiated when the document is read by the scanner unit 201, and in the first embodiment, there are two modes: "normal reading" in which the document is read with a normal amount of light irradiated, and "dark reading" in which the document is read with an amount of light irradiated that is less than the normal amount of light irradiated.

[0026] FIG. 4 shows an example of a receipt read in normal reading mode (first reading mode) or dark reading mode (second reading mode). Reference numeral 401 in FIG. 4(a) is the original receipt. The receipt original 401 includes a paper base portion 402 and a correction trace portion 403. Reference numeral 404 in FIG. 4(b) is the read image when the receipt original 401 is read in normal reading mode. Reference numeral 405 is a graph showing the conversion characteristics from the brightness of the read image 404 to RGB signal values. Graph 405 has the brightness of the read image 404 on the horizontal axis and the RGB signal value on the vertical axis, and shows the reading gradation characteristics when the brightness of the receipt original 401 read in normal reading mode is converted to RGB signal values.

[0027] As shown in graph 405, brightness values ​​equal to or greater than a certain value 406 are converted to white (RGB signal value = 255). In the example of FIG. 4(b), the brightness values ​​of the paper base 402 and correction trace 403 in the receipt manuscript 401 both exceed the certain value 406, and are therefore converted to white (255) in the RGB signal value. Therefore, in the scanned image 404, the paper base 402 and correction trace 403 in the receipt manuscript 401 are completely white, and the correction trace 407 is buried in the paper base 408 and disappears. In this case, the scanned image 404 does not satisfy the conditions that "the white of the gradation pattern does not become completely white on the electronic document" and "information such as correction traces does not disappear," and therefore is an unacceptable scanned image under the Electronic Bookkeeping Act.

[0028] In FIG. 4(c), 409 is a read image when the receipt document 401 is read in dark reading mode. 410 is a graph showing the conversion characteristics from brightness to RGB signal values ​​for the read image 409. Graph 410 can be interpreted in the same way as graph 405 in normal reading mode. When the receipt document 401 is read in dark reading mode, the amount of light irradiated is reduced compared to normal reading mode, so the brightness of the paper background and correction marks in graph 410 is lower than in graph 405 (shifted to the left on graph 410). As a result, the brightness of the paper background 402 and correction marks 403 in the receipt document 401 is lower than the constant value 406, so neither of them becomes white (255) in the RGB signal value, and information other than white is preserved. Therefore, in the read image 409, neither the paper background 411 nor the correction marks 412 becomes white, and visibility is maintained. Therefore, the scanned image 409 satisfies the conditions of the Electronic Bookkeeping Act.

[0029] In the dark reading mode of FIG. 4(c), the original 401 is irradiated with an amount of light that is 10% less than the amount of light in FIG. 4(b). However, the 10% reduction here is merely an example, and the value should be changed in the design depending on the brightness of the leader or the remaining correction marks. Dark reading can also be achieved by controlling the light receiving sensitivity and light receiving time rather than the amount of irradiated light. In other words, dark reading is achieved in the dark reading mode by lowering the light receiving sensitivity and shortening the light receiving time compared to the normal reading mode.

[0030] Next, the background removal level will be described. The background removal level is a setting item relating to the brightness level from which the background removal process starts converting to white. In the first embodiment, the background removal level value is set within a range of 0 to 8, and is defined so that the lower the level value, the larger the threshold value for converting to white. Therefore, when the background removal level value is low, the threshold value is large and therefore fewer pixels are converted to white, whereas when the background removal level value is high, the threshold value is small and therefore more pixels are converted to white. Furthermore, when the background removal level value is the minimum of 0, the result is the same as when the background removal process is not performed. Therefore, when the background removal level value is the minimum of 0, the background removal process is not performed.

[0031] The relationship between the background removal level and the background removal process will be explained below with reference to FIG. 5. The left side of FIG. 5 shows an image (referred to as the "output image" only when describing FIG. 5) after background removal process has been performed on a scanned image 409 (referred to as the "input image" only when describing FIG. 5) of a receipt document 401 acquired in dark reading mode. Here, examples are given for background removal level values ​​of 0, 1, 2, and 8. Also, to the right of each output image in FIG. 5, an input / output graph of the background removal process corresponding to each output image is shown. In each input / output graph, the horizontal axis represents the RGB signal value of the input image, and the vertical axis represents the RGB signal value of the output image, showing how the input signal is converted into an output signal by the background removal process. FIG. 5(a) shows an example when the background removal level value is 0. The threshold value when the background removal level value is 0 is set to 255, which is equal to the brightness value indicating white. As a result, when the background removal level value is 0, the background removal process is not performed, so the input / output graph also shows a straight line, and the input signal is output as is. Therefore, the output image 501 is the same as the input image.

[0032] FIG. 5(b) shows an example where the background removal level is 1. As mentioned above, the lower the level, the larger the threshold value. Here, for example, the threshold value when the background removal level is 1 is set to 241. Therefore, according to the input / output graph, all RGB signal values ​​of the input image equal to or greater than 241 are converted to 255 (white) by the background removal process. Because the RGB signal values ​​of the paper base of the input image are smaller than 241, they do not become white, as shown in paper base portion 503 of output image 502, and information other than white is retained. However, because the RGB signal values ​​of the correction traces of the input image exceed 241, they become 255 (white), as shown in correction trace portion 504 of output image 502. In this case, output image 502 does not satisfy the condition of the Electronic Document Act that "white should not become completely white in electronic documents."

[0033] FIG. 5(c) shows an example where the background removal level value is 2. Here, as an example, the threshold value when the background removal level value is 2 is set to 231. Therefore, in the input / output graph, all RGB signal values ​​of the input image that are 231 or greater are converted to 255 (white) by the background removal process. The RGB signal values ​​of the paper base and correction trace areas of the input image are both greater than the threshold value, so they are converted to 255 (white). As a result, in the output image 505, the correction trace area 506 is buried in the paper base area 507 and disappears. In this case, the output image 505 does not satisfy the condition of the Electronic Bookkeeping Act that "information such as correction traces will not be lost."

[0034] FIG. 5(d) shows an example where the background removal level is 8. Here, as an example, the threshold value when the background removal level is 8 is set to 162. As in the case where the background removal level is 2 (FIG. 5(c)), the RGB signal values ​​of both the paper base and correction trace areas of the input image are greater than the threshold value of 162, so the output image 508 is also the same as when the background removal level is 2 (FIG. 5(c)). Therefore, the output image 508 does not satisfy the condition of the Electronic Bookkeeping Act that "information such as correction traces will not be lost." However, in the input / output graph, because the threshold is smaller, the linear portion below the threshold is steeper than when the background removal level is 2 (FIG. 5(c)). As a result, when the background removal level is 8, the output image 508 becomes brighter overall as the background removal level becomes higher. Note that when the background removal level is 3 to 7, the tendency is basically the same as when the background removal level is 2 or 8, so a description of these will be omitted.

[0035] In the scan settings of the first embodiment, when the document type is set to the electronic document mode, the reading mode and background removal level are changed, and furthermore, UI operations on the operation unit 203 are restricted. FIG. 6 is a diagram showing an example of each setting UI screen displayed on the operation unit 203 of the first embodiment. The setting UI screens shown in FIG. 6 are displayed on the operation unit 203 by the CPU 205 (UI screen display means) via the operation unit I / F 207. This also applies to the setting UI screens shown in FIGS. 8 and 9, which will be described later. FIG. 6(a) is a diagram showing an example of a scan setting UI screen displayed on the operation unit 203. The scan setting UI screen of FIG. 6(a) displays buttons 601 to 605 for transitioning to each setting UI screen for color selection, magnification, reading mode, background removal level, and document type, as well as a start button 606 for starting reading by scanning. The scan setting UI screen also displays a button 607 for resetting various settings to their initial values.

[0036] 6(b) shows an example of a reading mode setting UI screen to which the screen transitions from the scan setting UI screen after button 603 is pressed. Buttons 608 and 609 corresponding to the normal reading mode and the dark reading mode, respectively, are displayed on the reading mode setting UI screen in FIG. 6(b). In the first embodiment, a reading mode flag is held as one of the scan setting values, with the normal reading mode set to 0 and the dark reading mode set to 1. As described above, when the user presses a button, the CPU 205 holds in the RAM 209 each of the scan setting values ​​associated with the setting change made by the UI operation.

[0037] Therefore, when button 608 corresponding to the normal reading mode is pressed on the reading mode setting UI screen, CPU 205 sets the value of the reading mode flag to 0, and when button 609 corresponding to the dark reading mode is pressed, CPU 205 sets the value of the reading mode flag to 1. As described above, button 603 is a button operated by the user to start setting the reading mode. Buttons 608 and 609 are buttons operated by the user to set the reading mode. Furthermore, a character based on the value of the reading mode flag is displayed in reading mode display portion 610 on the scan setting UI screen of FIG. 6(a). As a result, one of the reading mode names (i.e., "normal reading" or "dark reading") is displayed in reading mode display portion 610. Note that in the first embodiment, it is assumed that the normal reading mode is set by default.

[0038] FIG. 6(c) shows an example of a background removal level setting UI screen to which the screen transitions from the scan setting UI screen after button 604 is pressed. The background removal level setting UI screen of FIG. 6(c) displays a gauge 611 indicating the background removal level value in nine stages from 0 to 8, and a mark 612. On the gauge 611, the background removal level value decreases as you move to the left, and increases as you move to the right. In the example of FIG. 6(c), since the mark 612 on the gauge 611 is located third from the left, the background removal level value is set to 2.

[0039] The background removal level setting UI screen displays a “+” button 613, a “-” button 614, and an OK button 615. The user can arbitrarily change the background removal level value by pressing the “+” button 613 or the “-” button 614. When the “+” button 613 is pressed, the mark 612 moves to the right, and when the “-” button 614 is pressed, the mark 612 moves to the left. When the mark 612 is positioned at the leftmost position, the background removal level value is 0, which means that background removal processing is not performed. When the user presses the OK button 615, the background removal level setting UI screen transitions to the scan setting UI screen of FIG. 6( a). As described above, the button 604 is a button operated by the user to start setting the background removal level value (i.e., the threshold value). The “+” button 613 and the “-” button 614 are buttons operated by the user to set the background removal level value (i.e., the threshold value).

[0040] In the first embodiment, the value of the background removal level corresponding to the position of the mark 612 is stored in the RAM 209 by the CPU 205 as one of the scan setting values. At this time, a character based on the background removal level value is displayed in the background removal level display portion 616 on the scan setting UI screen of FIG. 6(a). As a result, one of the background removal level values ​​(i.e., any one of 0 to 8) is displayed in the background removal level display portion 616. Note that in the example of FIG. 6(c), the background removal level value stored in the RAM 209 by the CPU 205 is 2.

[0041] FIG. 6(d) shows an example of a document type setting UI screen to which the screen transitions from the scan setting UI screen after button 605 is pressed. Document type setting is a function for switching to image processing prepared in advance for each document type according to the document type set by the user. The document type setting UI screen in FIG. 6(d) displays buttons 617 to 620 corresponding to representative document types. The user can use buttons 617 to 620 to select and set one of "Text / Photo / Map," "Printed Photo," "Text," and "Electronic Document Save Mode" as the document type.

[0042] Button 617 corresponds to a document on which various contents such as text, photos, maps, etc. are arranged. When the user presses button 617, "text / photo / map" is selected as the document type. In this case, image processing is performed to separate the scanned data of the document into each content (text, photo, or map), and further, settings are made so that appropriate filter processing, etc. is performed for each separated area.

[0043] Button 618 is a button corresponding to a document that is mainly composed of photos. When the user presses button 618, "printed photo" is selected as the document type. In this case, settings are made so that filter processing, color conversion, etc. suitable for a document that is mainly composed of photos are executed. Button 619 is a button corresponding to a document that is mainly composed of text. When the user presses button 619, "text" is selected. In this case, settings are made so that filter processing, color conversion, etc. suitable for a document that is mainly composed of text are executed. Specifically, when button 619 corresponding to text is pressed, settings are made so that filter processing is executed that emphasizes the edges of the text in order to improve the readability of the text, for example.

[0044] Button 620 corresponds to the electronic document storage mode. When the user presses button 620, "electronic document storage mode" is selected as the document type. The user presses button 620 when making the electronic document compatible with the Electronic Bookkeeping Method. In this case, in order to ensure the conditions of the Electronic Bookkeeping Method, settings are made so that unnecessary image processing such as color conversion and filter processing is not performed. As described above, button 620 is a button operated by the user to set the electronic document storage mode (i.e., electronic document) as the document type. Note that the document type display portion 621 on the scan setting UI screen in FIG. 6(a) displays text based on the button 617-620 pressed by the user.

[0045] In the first embodiment, as described above, when the button 620 corresponding to the electronic document storage mode is pressed, the value of the reading mode flag and the value of the background removal level are changed to satisfy the conditions for retaining correction marks in the electronic bookkeeping method. Specifically, the CPU 205 sets the value of the reading mode flag to 1 and the value of the background removal level to 0 in order to perform dark reading and not perform background removal processing. This concludes the description of scan settings and UI operations.

[0046] [UI operation restrictions in electronic document save mode] Even if a user selects the electronic document storage mode on the document type setting UI screen of FIG. 6(d), the settings of the reading mode and background removal level, which are related to the conditions for retaining corrections under the Electronic Bookkeeping Method, may be changed unexpectedly. In this case, the MFP 101 generates an electronic document that does not satisfy the conditions for retaining corrections under the Electronic Bookkeeping Method. Therefore, when the electronic document storage mode is selected on the operation unit 203, UI operation restrictions are imposed to prevent changes to the settings related to the conditions for retaining corrections under the Electronic Bookkeeping Method. The following describes the restrictions on UI operation on the operation unit 203 with reference to FIGS. 7 and 8.

[0047] Fig. 7 is a flowchart showing the process from when the electronic document save mode is selected to when UI operation is restricted. Each step (control method of the image processing device) of the flowchart shown in Fig. 7 is realized by the CPU 205 (computer) reading out a program stored in the storage unit 210 into the RAM 206 and executing it in the MFP 101. In the flowchart shown in Fig. 7, first, in step S701, the CPU 205 (first determination means) determines whether the electronic document save mode has been selected as the type of document (determination step).

[0048] That is, CPU 205 determines whether button 620 (first predetermined button) corresponding to the electronic document save mode has been pressed (first predetermined operation). If button 620 corresponding to the electronic document save mode has been pressed, CPU 205 determines that the electronic document save mode has been selected as the type of document. In this case, processing proceeds to step S702. On the other hand, if button 620 corresponding to the electronic document save mode has not been pressed, CPU 205 determines that the electronic document save mode has not been selected as the type of document. In this case, the flowchart shown in FIG. 7 ends.

[0049] In step S702, the CPU 205 (reading mode setting means) sets the value of the reading mode flag to 1 so that dark reading is performed (reading mode setting process). In step S703, the CPU 205 (threshold setting means) sets the value of the background removal level to 0 so that background removal processing is not performed (threshold setting process). As a result, the threshold for the background removal processing is set to a value equal to the brightness value indicating white, for example, 255. In this case, 255 corresponds to the second threshold, and anything less than 255 corresponds to the first threshold. In step S704, the CPU 205 (change disabling means) restricts UI operations on the scan setting UI screen displayed on the operation unit 203, thereby disabling changes to the reading mode and background removal level settings (change disabling process). Specifically, the CPU 205 restricts operation by graying out the button 603 (first start button) corresponding to the reading mode and the button 604 (second start button) corresponding to the background removal level, and disabling input via the buttons 603 and 604. Thereafter, the flowchart shown in FIG. 7 ends.

[0050] 8 is a diagram showing an example of the scan setting UI screen when UI operation is restricted on the operation unit 203. In the first embodiment, as described above, input is disabled by graying out buttons as a method for disabling changes to the reading mode and background removal level settings. As shown in FIG. 8, on the scan setting UI screen when UI operation is restricted, the button 603 corresponding to the reading mode and the button 604 corresponding to the background removal level are grayed out to prevent the user from pressing them. This prevents the scan setting UI screen from transitioning to the reading mode setting UI screen or the background removal level setting UI screen, thereby preventing the user from changing the settings of the reading mode and background removal level.

[0051] At this time, characters based on the value of the reading mode flag and the value of the background removal level are displayed in the reading mode display portion 610 and the background removal level display portion 616, respectively. In the first embodiment, when the electronic document storage mode is selected on the document type setting UI screen, as described in the explanation of steps S702 and S703, the value of the reading mode flag is set to 1 and the value of the background removal level is set to 0. Therefore, as shown in Fig. 8, the reading mode display portion 610 displays "Dark Reading" and the background removal level display portion 616 displays "0". Furthermore, the selected "electronic document storage mode" is displayed in the document type display portion 621.

[0052] If the user selects a document type other than the electronic document storage mode on the document type setting UI screen, the CPU 205 cancels the input disablement caused by graying out the buttons in step S704. That is, if the CPU 205 (second determination means) (cancellation means) determines that one of the plurality of buttons 617-619 (second predetermined buttons) on the document type setting UI screen (FIG. 6(d)) has been pressed (a second predetermined operation), the CPU 205 cancels the operation restriction imposed in step S704. As a result, the user can cancel the operation restriction imposed in step S704 simply by pressing one of the plurality of buttons 617-619 other than the button 620 corresponding to the electronic document storage mode. This concludes the description of the restriction on UI operations on the operation unit 203. In this way, the MFP 101 can prevent unexpected setting changes by graying out the buttons 603 and 604 that allow for setting changes related to the conditions for retaining correction marks in the electronic bookkeeping method.

[0053] [summary] As explained above, in the first embodiment, when the electronic document save mode is selected on the MFP 101, dark reading is performed and background removal is not performed, while UI operations are restricted by graying out input. This allows the MFP 101 to prevent the loss of correction marks due to the reading mode or background removal process when generating an electronic document from a manuscript. Furthermore, the user can generate an electronic document from a manuscript in which the loss of correction marks is prevented simply by pressing the button 620 corresponding to the electronic document save mode on the MFP 101.

[0054] Second Embodiment The second embodiment will be described below with reference to Figures 9 and 10. The following mainly describes the differences from the first embodiment. In the first embodiment, when the electronic document storage mode was selected as the document type, the reading mode and background removal level were appropriately set to satisfy the conditions for retaining correction marks in the electronic bookkeeping method, and then UI operations were restricted to prevent unexpected UI operations. However, in the first embodiment, when a mode other than the electronic document storage mode was selected as the document type, it was not possible to use functions that satisfy the conditions for retaining correction marks in the electronic bookkeeping method (i.e., execution of the processes from step S702 to step S704).

[0055] For example, when scanning and saving a cadastral map required for land sales, a user often selects "Text / Photo / Map" as the document type to apply appropriate filter and color processing to the cadastral map. However, it is also necessary to be able to determine whether or not there are any corrections to the cadastral map required for land sales, just as it is when the electronic document storage mode is selected. Therefore, in the second embodiment, a button for making the electronic document compliant with the Electronic Bookkeeping Act is provided in addition to the button 620 corresponding to the electronic document storage mode. This allows for the restriction of UI operations to preserve corrections even when a document type other than the electronic document storage mode is selected.

[0056] In the second embodiment, the overall system configuration, the detailed configuration of the MFP 101, and the overall processing flow of the scan system in the MFP 101 are the same as those in the first embodiment, so descriptions thereof will be omitted. Furthermore, in the second embodiment, the same reference numerals are used to designate components that are the same as or similar to those in the first embodiment, and redundant descriptions will be omitted.

[0057] [Scan Settings and UI Operation] FIG. 9 is a diagram showing an example of each setting UI screen displayed on the operation unit 203 in the second embodiment. FIG. 9(a) is an example of a scan setting UI screen displayed on the operation unit 203 in the second embodiment, and is similar to the scan setting UI screen (FIG. 6(a)) in the first embodiment. FIG. 9(b) shows an example of a background removal level setting UI screen to which the scan setting UI screen transitions after the button 604 is pressed. The only difference between the background removal level setting UI screen in FIG. 9(b) and the background removal level setting UI screen (FIG. 6(c)) in the first embodiment is the provision of a correction mark disappearance prevention button 901. Pressing the correction mark disappearance prevention button 901 performs settings that satisfy the correction mark retention conditions of the electronic bookkeeping method. Note that a detailed flowchart when the correction mark disappearance prevention button 901 is pressed will be described later in [Restrictions on UI Operation in Correction Mark Disappearance Prevention Settings].

[0058] FIG. 9(c) shows an example of a background removal level setting UI screen that has changed as a result of pressing the button 901 in FIG. 9(b). In order to preserve the correction marks, the gauge 611, mark 612, "+" button 613, and "-" button 614 related to the background removal level are grayed out, making the UI inoperable. This makes it impossible to change the background removal level setting. Furthermore, in order to prevent the background removal process from being executed, the mark 612 is moved to the leftmost position, and the background removal level value is set to 0. The user can release the grayed-out state in which the UI cannot be operated by pressing the correction mark disappearance prevention button 901 again.

[0059] Fig. 9(d) shows an example of a scan setting UI screen to which the transition from the background removal level setting UI screen occurs after the OK button 615 in Fig. 9(c) is pressed. On the scan setting UI screen in Fig. 9(d), the text "Prevent Correction Mark Loss" is displayed in the background removal level display portion 616, based on the pressing of the "Prevent Correction Mark Loss" button 901. Furthermore, on the scan setting UI screen in Fig. 9(d), "Dark Reading" is displayed in the reading mode display portion 610.

[0060] FIG. 9(e) shows an example of a reading mode setting UI screen to which the screen transitions from the scan setting UI screen after the button 603 in FIG. 9(d) is pressed. The only difference between the reading mode setting UI screen in FIG. 9(e) and the reading mode setting UI screen (FIG. 6(b)) in the first embodiment is that a correction mark disappearance prevention button 902 is provided. In the second embodiment, in conjunction with the change in the background removal level setting UI screen in FIG. 9(b), the buttons 608 and 609 in the reading mode setting UI screen in FIG. 9(e) are also grayed out, making the UI inoperable. This makes it impossible to change the reading mode setting. Furthermore, to perform background reading, the value of the reading mode flag is set to 1. Furthermore, on the reading mode setting UI screen in FIG. 9(e), as with the background removal level setting UI screen in FIG. 9(c), the user can cancel the grayed-out state in which the UI cannot be operated by pressing the correction mark disappearance prevention button 902.

[0061] Therefore, when the correction mark disappearance prevention button 901 or the correction mark disappearance prevention button 902 is pressed twice, the grayed-out state in which the UI cannot be operated is released on the reading mode setting UI screen and the background removal level setting UI screen. Note that the same process occurs as described above when the correction mark disappearance prevention button 902 is pressed on the reading mode setting UI screen from which the grayed-out state in which the UI cannot be operated is released. That is, the buttons 608 and 609 are grayed out, the UI cannot be operated, and the value of the reading mode flag is set to 1. Furthermore, on the background removal level setting UI screen, in conjunction with the change in the reading mode setting UI screen, the gauge 611, the mark 612, the "+" button 613, and the "-" button 614 are grayed out, the UI cannot be operated, and the value of the background removal level is set to 0. Furthermore, on the scan setting UI screen, "correction mark disappearance prevention" is displayed in the background removal level display portion 616.

[0062] In the second embodiment, even if the settings of the reading mode and background removal level cannot be changed, the user can select one of "Text / Photo / Map," "Printed Photo," "Text," and "Electronic Document Save Mode" as the document type. This is different from the first embodiment. The above is a description of the scan settings and UI operations in the second embodiment.

[0063] [UI operation restrictions for correction mark disappearance prevention settings] Fig. 10 is a flowchart from when correction mark disappearance prevention buttons 901, 902 are pressed until UI operation is restricted. Each step (control method of the image processing apparatus) of the flowchart shown in Fig. 10 is realized by the CPU 205 (computer) reading out a program stored in the storage unit 210 into the RAM 206 and executing it in the MFP 101. In the flowchart shown in Fig. 10, first, in step S1001, the CPU 205 (first determination means) determines whether or not the correction mark disappearance prevention buttons 901, 902 (first predetermined buttons) have been pressed (first predetermined operation) (determination step).

[0064] If the CPU 205 determines that the correction mark disappearance prevention buttons 901, 902 have been pressed, the process proceeds to step S1002. On the other hand, if the CPU 205 determines that the correction mark disappearance prevention buttons 901, 902 have not been pressed, the flowchart shown in Fig. 10 ends. Steps S1002 and S1003 are the same as the above-mentioned steps S702 and S703, respectively, and therefore their description will be omitted. In step S1004, the CPU 205 (change disabling means) restricts UI operations on the reading mode setting UI screen and the background removal level setting UI screen, thereby disabling changes to the reading mode and background removal level settings (change disabling step).

[0065] Specifically, the CPU 205 grays out the buttons 608 and 609 (first setting buttons) on the reading mode setting UI screen (FIG. 9(e)) displayed on the operation unit 203. As a result, the CPU 205 restricts operation by invalidating input using the buttons 608 and 609. Note that the CPU 205 (second determination means) (release means) releases the operation restriction in step S1004 when it determines that the correction mark disappearance prevention button 902 (second predetermined button) has been pressed (second predetermined operation) on the reading mode setting UI screen (FIG. 9(e)). As a result, the user can release the operation restriction in step S1004 simply by pressing the correction mark disappearance prevention button 902.

[0066] Furthermore, the CPU 205 grays out the gauge 611, the mark 612, the "+" button 613 (second setting button), and the "-" button 614 (second setting button) on the background removal level setting UI screen (FIG. 9(c)) displayed on the operation unit 203. As a result, the CPU 205 restricts operation by invalidating input using the gauge 611, the mark 612, the "+" button 613, and the "-" button 614. Note that when the CPU 205 (second determination means) (release means) determines that the correction mark disappearance prevention button 901 (second predetermined button) has been pressed (second predetermined operation) on the background removal level setting UI screen (FIG. 9(c)), the CPU 205 releases the operation restriction imposed in step S1004. As a result, the user can release the operation restriction imposed in step S1004 simply by pressing the correction mark disappearance prevention button 901.

[0067] In step S1005, the CPU 205 (notification display means) displays "Prevent Correction Mark Loss" (notification) in the background removal level display portion 616 on the scan setting UI screen (FIG. 9(d)) displayed on the operation unit 203. As a result, "Prevent Correction Mark Loss" is displayed near the button 604 corresponding to the background removal level. When "Prevent Correction Mark Loss" is displayed in this manner, when the user attempts to touch button 604 in order to change the background removal level setting, the user can see "Prevent Correction Mark Loss" displayed near the button and know that operation restrictions are in place. Thereafter, the flowchart shown in FIG. 10 ends.

[0068] Furthermore, although not shown, the CPU 205 (notification display means) may display "Prevent Correction Mark Loss" instead of "Dark Reading" in the reading mode display area 610 on the scan setting UI screen ( FIG. 9(d) ) displayed on the operation unit 203. As a result, "Prevent Correction Mark Loss" is displayed near the button 603 corresponding to the reading mode. When "Prevent Correction Mark Loss" is displayed in this manner, the user can see "Prevent Correction Mark Loss" displayed near the button 603 when attempting to touch the button 603 to change the reading mode setting, and can thereby know that operation restrictions have been imposed. In this case, "Prevent Correction Mark Loss" may be displayed in both the background removal level display area 616 and the reading mode display area 610, or may be displayed only in the reading mode display area 610.

[0069] The above is the description of the restriction on UI operations when the correction mark loss prevention buttons 901 and 902 are pressed. In this way, the MFP 101 can prevent unexpected setting changes by graying out buttons 608, 609, 613, 614, etc., which allow for setting changes related to the conditions for retaining correction marks in the electronic bookkeeping method.

[0070] [summary] As described above, in the second embodiment, when the correction trace loss prevention buttons 901 and 902 are pressed on the MFP 101, dark reading is performed and background removal is not performed, while UI operations are restricted by graying out input. This allows the MFP 101 to prevent correction traces from being lost due to the reading mode or background removal processing when generating an electronic document from a document. Unlike the first embodiment, the MFP 101 can also prevent correction traces from being lost when generating an electronic document from a document even when a mode other than the electronic document save mode is selected as the document type. Furthermore, a user can generate an electronic document from a document in which the loss of correction traces is prevented by simply pressing either of the correction trace loss prevention buttons 901 and 902 on the MFP 101.

[0071] <Other> Although preferred embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments and various modifications and changes are possible within the scope of the gist thereof. For example, the method of restricting UI operations is not limited to graying out. However, when restricting UI operations by a method other than graying out, it is desirable that the UI screen be one that "enables the user to recognize that UI operations are being restricted" and "enables the user to release the restriction on UI operations."

[0072] Also, in general situations where dark reading is performed, the value of the background removal level is often set to 0. Therefore, when button 609 (first predetermined button) corresponding to the dark reading mode is pressed (first predetermined operation) and the value of the reading mode flag is set to 1, CPU 205 may set the value of the background removal level to 0 in conjunction with this and further restrict UI operations. Alternatively, when “-” button 614 (first predetermined button) is pressed (first predetermined operation) and the value of the background removal level is set to 0, CPU 205 may set the value of the reading mode flag to 1 in conjunction with this and further restrict UI operations. In these cases, the user can generate an electronic document from a manuscript in which the loss of correction traces is suppressed, simply by performing an operation of pressing button 609 corresponding to the dark reading mode or “-” button 614 on MFP 101.

[0073] Furthermore, in step S703 of the first embodiment and step S1003 of the second embodiment, if the conditions of the Electronic Bookkeeping Act are satisfied, the CPU 205 may set the background removal level threshold to a value less than 255. In this case, the value set for the background removal level threshold corresponds to the second threshold, and a value less than the set value for the background removal level threshold corresponds to the first threshold. Furthermore, in the second embodiment, only one of the correction mark disappearance prevention buttons 901 and 902 may be provided. Furthermore, buttons related to the present invention are not limited to buttons on a UI screen, and may be buttons with physical mechanisms, except for those requiring a display function such as graying out. Furthermore, the present invention can be implemented in a single-function scanner device, etc., in addition to an MFP.

[0074] The present invention can also be realized by supplying a program that realizes one or more functions of each of the above embodiments to a system or device via a network or storage medium, and having one or more processors in the computer of the system or device read and execute the program. The present invention can also be realized by a circuit (e.g., ASIC) that realizes one or more functions.

[0075] The disclosure of each embodiment includes the following configurations, methods, and programs. (Configuration 1) An image processing apparatus having a reading means for reading an original document and acquiring read image data, an adjustment means for converting the color of pixels in the read image data that have a brightness equal to or greater than a threshold value to white, and an operation means for allowing a user to perform at least a user operation on the reading means and a user operation on the adjustment means, a first determination means for determining whether a first predetermined operation has been performed by the operation means; a reading mode setting means for setting a reading mode of the reading means to a second reading mode in which the document is read under darker conditions than in the first reading mode when the first determination means determines that the first predetermined operation has been performed by the operating means; a threshold setting means for setting the threshold of the adjusting means to a second threshold that is greater than the first threshold when the first determining means determines that the first predetermined operation has been performed by the operating means; and a change disabling unit that disables the change of the second reading mode set by the reading mode setting unit and the change of the second threshold value set by the threshold value setting unit. (Configuration 2) The image processing device according to configuration 1, wherein the second threshold value is a brightness value that indicates white. (Configuration 3) The image processing device according to configuration 1 or 2, wherein the first predetermined operation is an operation performed by a user on a first predetermined button of the operation means. (Configuration 4) The image processing device according to configuration 3, wherein the first predetermined button is a button that a user operates to set an electronic document as the type of the document. (Configuration 5) An image processing device according to configuration 3 or 4, characterized in that the first predetermined button is a button that a user operates to cause the image processing device to execute the reading mode setting means, the threshold setting means, and the non-changeable means. (Configuration 6) The image processing device according to any one of configurations 3 to 5, wherein the first predetermined button is a button that a user operates to set the second reading mode as the reading mode of the reading means. (Configuration 7) The image processing device according to any one of configurations 3 to 6, wherein the first predetermined button is a button that is operated by a user to set the second threshold as the threshold of the adjustment means. (Configuration 8) An image processing device described in any one of configurations 1 to 7, characterized in that the change prohibition means restricts operations in the operation means so that the user cannot set the reading mode of the reading means and the threshold value of the adjustment means. (Configuration 9) A UI screen display means for displaying a UI screen on the operation means is provided, The image processing device according to configuration 8, wherein the change-disabling means restricts the operation by graying out a first start button that the user operates to start setting the reading mode of the reading means and a second start button that the user operates to start setting the threshold of the adjusting means on the UI screen of the operating means. (Configuration 10) A UI screen display means for displaying a UI screen on the operation means is provided, The image processing device described in configuration 8, wherein the change-disabling means restricts operation by graying out a first setting button that a user operates to set the reading mode of the reading means and a second setting button that a user operates to set the threshold value of the adjusting means on the UI screen of the operating means. (Configuration 11) A UI screen display means for displaying a UI screen on the operation means; 9. The image processing device according to configuration 8, further comprising: a notification display unit that displays a notification that the operation restriction is being imposed on the UI screen of the operation unit. (Configuration 12) The change prohibiting means restricts the operation by graying out a first setting button operated by a user to set the reading mode of the reading means and a second setting button operated by a user to set the threshold value of the adjusting means on the UI screen of the operating means, The image processing device described in configuration 11, wherein the notification display means displays a notification that the operation restriction is in effect on the UI screen of the operation means near a first start button that the user operates to start setting the reading mode of the reading means or near a second start button that the user operates to start setting the threshold of the adjustment means. (Configuration 13) A second determination means for determining whether a second predetermined operation has been performed by the operation means; 13. The image processing device according to any one of configurations 8 to 12, further comprising a release means for releasing the operation restriction when the second determination means determines that the second predetermined operation has been performed by the operation means. (Configuration 14) The image processing device according to configuration 13, wherein the second predetermined operation is an operation performed by a user on a second predetermined button of the operation means. (Configuration 15) The image processing device described in Configuration 14, wherein the second predetermined button is one of a plurality of buttons for setting the type of the document that the user operates to set the type of the document to something other than an electronic document. (Configuration 16) The image processing device described in Configuration 14, characterized in that the second predetermined button is a button that a user operates to cause the image processing device to execute the reading mode setting means, the threshold setting means, and the non-changeable means. (Configuration 17) An image processing device according to any one of configurations 1 to 16, characterized in that the dark conditions are at least one of conditions of a lower amount of irradiated light, lower light receiving sensitivity, and shorter light receiving time than in the first reading mode. (Method 1) A control method for an image processing apparatus having a reading unit that reads an original document and acquires read image data, an adjustment unit that converts the color of pixels in the read image data that have a brightness equal to or greater than a threshold value to white, and an operation unit that allows a user to at least perform operations on the reading unit and the adjustment unit, a determination step of determining whether a predetermined operation has been performed by the operation means; a reading mode setting step of setting a reading mode of the reading means to a second reading mode in which the document is read under darker conditions than in the first reading mode when it is determined in the determining step that the predetermined operation has been performed by the operating means; a threshold setting step of setting the threshold of the adjusting means to a second threshold that is greater than a first threshold when it is determined in the determining step that the predetermined operation has been performed by the operating means; a change disabling step of disabling the second reading mode set in the reading mode setting step and the second threshold value set in the threshold value setting step. (Program 1) A program for causing a computer to execute each means of the image processing device according to any one of configurations 1 to 17. [Explanation of symbols]

[0076] 101 MFP (Image Processing Device) 201 Scanner unit (reading means) 203 Operation unit (operation means) 205 CPU (first determination means) (read mode setting means) (threshold value setting means) (change-disabling means) 216 Data processing unit (adjustment means)

Claims

1. An image processing apparatus having a reading unit that reads an original document and acquires read image data, an adjustment unit that converts a color of a pixel having a brightness equal to or greater than a threshold value in the read image data to white, and an operation unit that allows a user to perform at least a user operation on the reading unit and a user operation on the adjustment unit, a first determination means for determining whether a first predetermined operation has been performed by the operation means; a reading mode setting means for setting a reading mode of the reading means to a second reading mode in which the document is read under darker conditions than in the first reading mode when the first determination means determines that the first predetermined operation has been performed by the operating means; a threshold setting means for setting the threshold of the adjusting means to a second threshold that is greater than the first threshold when the first determining means determines that the first predetermined operation has been performed by the operating means; and a change disabling unit that disables the second reading mode set by the reading mode setting unit and the second threshold value set by the threshold value setting unit.

2. The image processing device according to claim 1 , wherein the second threshold value is a brightness value that indicates white.

3. 2. The image processing apparatus according to claim 1, wherein the first predetermined operation is an operation performed by a user on a first predetermined button of the operation unit.

4. 4. The image processing apparatus according to claim 3, wherein the first predetermined button is a button that a user operates to set an electronic document as the type of the original.

5. 4. The image processing apparatus according to claim 3, wherein the first predetermined button is a button that a user operates to cause the image processing apparatus to execute the reading mode setting means, the threshold value setting means, and the change prohibiting means.

6. 4. The image processing apparatus according to claim 3, wherein the first predetermined button is a button that is operated by a user to set the second reading mode as the reading mode of the reading means.

7. 4. The image processing apparatus according to claim 3, wherein the first predetermined button is a button that is operated by a user to set the second threshold as the threshold of the adjustment means.

8. 2. The image processing device according to claim 1, wherein the change prohibiting means restricts the operation of the operating means so as to prohibit a user from setting the reading mode of the reading means and from setting the threshold value of the adjusting means.

9. a UI screen display means for displaying a UI screen on the operation means, The image processing device described in claim 8, characterized in that the change-disabling means restricts operation by graying out a first start button that the user operates to start setting the reading mode of the reading means and a second start button that the user operates to start setting the threshold of the adjustment means on the UI screen of the operation means.

10. a UI screen display means for displaying a UI screen on the operation means, The image processing device described in claim 8, characterized in that the change-disabling means restricts operation by graying out a first setting button that the user operates to set the reading mode of the reading means and a second setting button that the user operates to set the threshold value of the adjustment means on the UI screen of the operation means.

11. a UI screen display means for displaying a UI screen on the operation means; 9. The image processing apparatus according to claim 8, further comprising a notification display unit that displays a notification that the operation restriction is being imposed on the UI screen of the operation unit.

12. the change prohibiting means restricts the operation by graying out a first setting button operated by a user to set the reading mode of the reading means and a second setting button operated by a user to set the threshold value of the adjusting means, on the UI screen of the operating means; The image processing device described in claim 11, characterized in that the notification display means displays a notification that the operation restriction is in effect on the UI screen of the operation means, near a first start button that the user operates to start setting the reading mode of the reading means, or near a second start button that the user operates to start setting the threshold of the adjustment means.

13. a second determination means for determining whether a second predetermined operation has been performed by the operation means; 9. The image processing apparatus according to claim 8, further comprising a release unit that releases the operation restriction when the second determination unit determines that the second predetermined operation has been performed on the operation unit.

14. 14. The image processing apparatus according to claim 13, wherein the second predetermined operation is an operation performed by a user on a second predetermined button of the operation unit.

15. 15. The image processing apparatus according to claim 14, wherein the second predetermined button is one of a plurality of buttons for setting the type of the document that is operated by a user to set the type of the document to something other than an electronic document.

16. 15. The image processing apparatus according to claim 14, wherein the second predetermined button is a button that a user operates to cause the image processing apparatus to execute the reading mode setting means, the threshold value setting means, and the change prohibiting means.

17. 2. The image processing apparatus according to claim 1, wherein the dark conditions are at least one of conditions of a lower amount of irradiated light, a lower light receiving sensitivity, and a shorter light receiving time than those in the first reading mode.

18. A control method for an image processing apparatus having a reading unit that reads an original document and acquires read image data, an adjustment unit that converts a color of a pixel in the read image data that has a brightness equal to or greater than a threshold value to white, and an operation unit that allows a user to perform at least a user operation on the reading unit and a user operation on the adjustment unit, a determination step of determining whether a predetermined operation has been performed by the operation means; a reading mode setting step of setting a reading mode of the reading means to a second reading mode in which the document is read under darker conditions than in the first reading mode when it is determined in the determining step that the predetermined operation has been performed by the operating means; a threshold setting step of setting the threshold of the adjusting means to a second threshold that is greater than a first threshold when it is determined in the determining step that the predetermined operation has been performed by the operating means; a change disabling step of disabling the second reading mode set in the reading mode setting step and the second threshold value set in the threshold value setting step.

19. 2. A program for causing a computer to execute each means of the image processing apparatus according to claim 1.

Images