Image processing device

Abstract

To provide a binarization processing capable of adjusting a character and a line width in a range where blacked destruction and white skipping do not occur, while removing winkle and contamination and remaining a character to be thinly written.SOLUTION: An image processing device comprises: an edge determination part that determines whether or not each pixel is an edge part to an image obtained by reading a script (S602); and a binarization processing part to perform a binarization of the image. The binarization processing part calculates a threshold value for performing the binarization of the pixel determined as an edge in the edge determination part from a whole image (S603), and calculates a threshold value for performing the binarization of the pixel that is not determined as an edge in the edge determination part from a neighbor pixel value of an object pixel and a thin adjustment value (S606).SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The present invention relates to an image processing apparatus that performs image processing on an image obtained by reading an original document. [Background technology]

[0002] In recent years, there has been an increase in the number of cases where documents such as printed matter, slips, and checks are scanned and digitized in large quantities using scanners. In this case, binary image data of the document image is often generated. Among such large volumes of documents, documents with wrinkles or dirt, or documents with faintly written characters, may be scanned and processed in a mixed state. When these documents are scanned, there are some systems that perform binarization processing to remove the wrinkles and dirt while leaving the faintly written characters (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-52731 A Summary of the Invention [Problem to be solved by the invention]

[0004] Furthermore, there is a demand for thicker or thinner characters and lines in order to improve the recognition rate and visibility of OCR processing.

[0005] To provide a binarization process that can remove wrinkles and dirt, leave lightly written characters, and adjust the thickness of characters and lines within a range that does not cause black crush or white blowout. [Means for solving the problem]

[0006] The image processing device according to the present invention comprises: an edge determination unit that determines whether each pixel in an image obtained by reading an original is an edge portion; a binarization processing unit that binarizes the image; Equipped with The binarization processing unit includes: a threshold value for binarizing pixels determined to be edges by the edge determination unit is calculated from an entire image; The threshold value for binarizing a pixel determined not to be an edge by the edge determination unit is calculated from pixel values ​​in the vicinity of the target pixel and a line width adjustment value. Effect of the Invention

[0007] According to the present invention, it is possible to remove wrinkles and dirt, leave lightly written characters, and adjust the thickness of characters and lines within a range that does not cause crushed black or blown white. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a diagram showing an example of an image reading system to which an image processing apparatus according to an embodiment of the present invention can be applied. [Diagram 2] FIG. 1 is a diagram showing an example of the configuration of a sheet-fed scanner according to an embodiment of the scanner. [Diagram 3] FIG. 4 is a block diagram showing an example of a control configuration of a scanner. [Figure 4] FIG. 4 is a diagram showing an example of a UI of a scan application in the embodiment. [Diagram 5] 5 is a flowchart showing an example of image processing according to the first embodiment. [Figure 6] 5 is a flowchart showing an example of image processing according to the first embodiment. [Figure 7] FIG. 13 is a diagram showing an example of a graph showing average edge levels for each brightness level. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, an embodiment of the invention will be described with reference to the drawings.

[0010] Hereinafter, an image reading system including an image reading device and an information processing device connectable to the image reading device will be described.

[0011] FIG. 1 is a diagram showing an example of an image reading system to which an image processing apparatus according to an embodiment of the present invention can be applied.

[0012] In Fig. 1, scanner 100 is an image reading device that reads image data from a document. Scanner 100 is communicably connected to a personal computer (PC) 200. Scanner 100 and PC 200 may be connected via a USB interface or the like, or may be connected via a network. The network may be either wired or wireless. Personal computer (PC) 200 is an information processing device that controls scanner 100.

[0013] The configuration and operation of the scanner 100 will be described below with reference to FIG.

[0014] 2 is a diagram showing an example of the configuration of a sheet-fed scanner showing one embodiment of the scanner 100. In this embodiment, a sheet-fed scanner that sequentially scans stacked documents (hereinafter referred to as "sheets") will be used for explanation.

[0015] As shown in FIG. 2, the scanner 100 includes an automatic document feeder (hereinafter referred to as "ADF") 101. A plurality of sheets are stacked on the sheet stacking platform 1, and the sheet stacking platform 1 is configured to be freely raised and lowered. A sheet stacking platform drive motor (not shown) raises and lowers the sheet stacking platform 1. The sheet detection sensor 3 detects that the sheets stacked on the sheet stacking platform 1 are at the sheet intake position. The sheet stacking detection sensor 12 detects that the sheets are stacked on the sheet stacking surface 1a of the sheet stacking platform 1. The document jump-up detection sensor 35 includes a plurality of sensors arranged in a direction perpendicular to the sheet stacking surface 1a, and detects the jump-up of the sheets stacked on the sheet stacking platform 1. For example, the document jump-up detection sensor 35 can detect the jump-up of the document that occurs when a stapled document is loaded on the sheet stacking platform 1 and fed. This makes it possible to control the feeding of the stapled document, for example, by stopping the feeding of the stapled document.

[0016] The pickup roller 4, which is an example of a sheet pickup section, sends out a sheet on the sheet stacking table 1 from the sheet stacking table 1. A pickup roller drive motor (not shown) rotates the pickup roller 4 in a direction to take in the sheet. The pickup roller 4 can move to a sheet take-in position and a retracted position above the sheet take-in position. The pickup roller 4 is moved to the sheet take-in position when taking in a sheet, and is moved to the retracted position when the take-in is completed. The pickup roller 4 plays an auxiliary role in ensuring that separation and feeding are performed reliably by a separation roller pair 42, which will be described later. If the pickup roller 4 sends the sheet on the sheet stacking table 1 into the nip portion of the separation roller pair 42, separation and feeding by the separation roller pair 42 can be performed reliably.

[0017] In the separation roller pair 42, the feed roller 6 is driven by a feed motor (not shown) to rotate in a direction to feed the sheet downstream in the conveying direction (feeding direction). The separation roller 7 constantly receives a rotational force from the separation motor (not shown) via a torque limiter (slip clutch) (not shown) that rotates in a direction to push back the sheet upstream in the conveying direction.

[0018] When one sheet is present between the feed roller 6 and the separation roller 7, the torque in the direction in which the sheet is fed downstream by the feed roller 6 due to the frictional force between the separation roller 7 and the sheet fed downstream is greater than the upper limit of the torque in the direction in which the separation roller 7 pushes the sheet back upstream, which is transmitted by the torque limiter described above. Therefore, the separation roller 7 rotates following the feed roller 6.

[0019] On the other hand, when there are multiple sheets between the feeding roller 6 and the separation roller 7, the separation roller 7 receives rotation from the roller shaft in a direction to push the sheets back upstream, so that sheets other than the topmost sheet are not transported downstream.

[0020] In this way, due to the action of the feed roller 6 to feed the sheets downstream and the action of the separation roller 7 to prevent the sheets from being transported downstream, even if the sheets are overlapped and sent to the nip portion (contact portion between the feed roller 6 and the separation roller 7) formed between the feed roller 6 and the separation roller 7, only the topmost sheet is fed downstream and the other sheets are not transported downstream. As a result, the overlapped sheets are separated and fed.

[0021] The feed roller 6 and the separation roller 7 constitute a pair of separation rollers 42 (sheet separation section). In this embodiment, the separation roller pair 42 is used, but instead of the separation roller pair 42, a separation belt roller pair may be used in which either the separation roller or the feed roller is a belt. The separation roller may be replaced with a separation pad that abuts against the sheet to prevent multiple sheets from being transported downstream. The separation roller 7 may be used to abut against the sheet like a separation pad without rotating.

[0022] The sheets stacked on the sheet stacking tray 1 are separated one by one and taken into the scanner 100 by the sheet pickup section composed of the pickup roller 4, the feeding roller 6, the separation roller 7, etc. thus configured.

[0023] Furthermore, by providing the double-feed detection sensor 30 at a position where the separated sheets pass (that is, downstream of the pair of separation rollers 42), it is possible to detect whether the sheets have been separated one by one by the sheet separation unit.

[0024] A conveying motor (not shown) drives other rollers (sheet conveying section) to convey the separated sheet to an image reading position where the image on the sheet is read by image reading sensors 14 and 15, and further to a discharge position. The conveying motor also drives each roller so that the sheet conveying speed can be changed according to settings such as the optimum speed for reading the sheet and the sheet resolution.

[0025] A nip gap adjustment motor (not shown) adjusts the gap between the feeding roller 6 and the separation roller 7, or the pressure (nip pressure) with which the feeding roller 6 presses against the separation roller 7 via the sheet. This allows the gap or pressure to be adjusted to suit the thickness of the sheet, allowing the sheet to be separated.

[0026] A registration clutch (not shown) transmits or blocks the rotational driving force of the conveying motor to registration rollers 18 (sheet conveying section). By stopping the rotation of the first registration roller pair consisting of registration rollers 17 and 18, the leading edge of the fed sheet is abutted against the nip portion of the registration roller pair to correct the skew of the sheet.

[0027] The second registration roller pair consisting of registration rollers 20 and 21, the conveying roller pair consisting of conveying rollers 22 and 23, the conveying roller pair consisting of conveying rollers 24 and 25, and the discharge roller pair consisting of discharge rollers 26 and 27 convey the sheet, and finally convey it to a discharge stacking section 44. The discharge sensor 16 detects the passage of the conveyed sheet. The two guide plates, the upper guide plate 40 and the lower guide plate 41, guide the sheet conveyed by the separation roller pair, the registration roller pair, each conveying roller pair, and the discharge roller pair.

[0028] The pre-registration sensor 32 is disposed upstream of the first registration roller pair 17, 18 and detects the fed sheet. The post-registration sensor 34 is disposed downstream of the second registration roller pair 20, 21 and detects the conveyed sheet. Furthermore, the registration sensor 33 is disposed downstream of the first registration roller pair 17, 18 and upstream of the second registration roller pair 20, 21 and detects the conveyed sheet.

[0029] When the post-registration sensor 34 detects the sheet, a control unit (CPU 306 described later) issues an instruction to read the image to the image reading sensors 14 and 15, and the image on the conveyed sheet is read. The image reading sensors 14 and 15 are provided with platen rollers 14a and 15a, respectively, so that the sheet can be read while being in close contact with the image reading sensors 14 and 15.

[0030] The images of the sheets read by the image reading sensors 14 and 15 are transmitted to an external device such as an information processing device via an interface unit (not shown).

[0031] FIG. 3 is a block diagram showing an example of a control configuration of the scanner 100. As shown in FIG.

[0032] A / D conversion units (ADC) 301a, 301b perform analog processing such as amplification and black level clamping on the output signals of the line image sensors (image reading sensors 14, 15 in FIG. 2), and then convert the signals into digital data (image data). An image processing unit 302 controls the line image sensors 14, 15 and the A / D conversion units 301a, 301b, and performs various image processing on the image data output from the A / D conversion units 301a, 301b. The image processing unit 302 has an image processing buffer that stores image data therein.

[0033] The I / F 304 is an interface for communicating with an external host device (such as the PC 200). The I / F 304 is connected to an external host device such as a PC via a signal cable 305. For example, the I / F 304 is a USB interface. The I / F 304 may be a wired interface such as a USB interface or a wired LAN interface, or may be a wireless interface such as a wireless LAN, a wireless USB, BLUETOOTH (registered trademark), or NFC.

[0034] The CPU 306 is a control unit that controls the scanner 100. The image processing unit 302 and the CPU 306 are connected via a bus 307. The CPU 306 accesses the RAM 303 and the ROM 310 via the image processing unit 302.

[0035] The ROM 310 stores programs and various data.

[0036] The RAM 303 functions as a work memory for the CPU 306 .

[0037] The driving unit 309 is a motor or the like for driving various loads such as the pickup roller 4, the feeding roller 6, and the separation roller 7. The motor driver 308 is a control circuit for controlling the driving unit 309 based on instructions from the CPU 306.

[0038] 4 is a diagram of an example of an application in this embodiment. This application may be provided inside the scanner 100, or may be provided in the PC 200 so that adjustment values ​​can be set via the I / F 304, and a display unit for displaying a GUI may be provided in either the scanner 100 or the PC 200. The user inputs to this application the mode (color, gray, black and white), paper size (A4, letter), resolution (200, 300), and the degree of thinning or thickening of characters and lines (hereinafter, line width) (9 levels from 1 to 9). By pressing the scan button after inputting the settings, the document placed on the sheet stacking tray 1 of the scanner 100 is read and output according to the application settings.

[0039] 5 is a flowchart showing an example of image processing according to the embodiment. In this embodiment, the input image is described as an 8-bit grayscale image, but it may be a full-color image. When a full-color image is input, an 8-bit grayscale image is generated from the full-color image in the image processing unit 302, and the process of this flowchart is executed using the 8-bit grayscale image as an input image.

[0040] Fig. 5 is a flowchart of the entire binarization process in this embodiment. The binarization process in this embodiment will be described below with reference to Fig. 5. Note that each process in the following description is executed by the image processing unit 302 or the CPU 306, and functions as an edge determination unit that performs edge determination (to be described later), a binarization processing unit that performs binarization processing, etc.

[0041] First, in S501, edge detection processing (for example, edge detection processing using a Sobel filter) is performed on the input image, the edge level of each pixel is calculated, and edge level data is generated. Here, the edge level indicates the output value of each pixel in the image to which the edge detection processing has been applied, and a large output value in the image after the edge detection processing corresponds to a high edge level.

[0042] Next, in S502, the number of pixels for each brightness (0 to 255 in this embodiment) of the input image is calculated.

[0043] Next, in S503, for each pixel whose edge level was calculated in S501, the edge levels of the pixels included in a specified range around that pixel (e.g., data of 5 x 5 pixels) are added, and the result of the addition is regarded as the edge level of the surrounding pixels of that pixel (surrounding pixel edge level addition process).

[0044] Next, in S504, for each brightness calculated in S502 for which the number of pixels is one or more, the surrounding pixel edge levels (calculated in S504 above) for each pixel of that brightness are summed up, and the sum is divided by the number of pixels calculated in S502 above to find the average edge level for each brightness. The value of the surrounding pixel edge level for each pixel is larger the more edges there are nearby the pixel. Therefore, a brightness with a large average edge level is considered to be the brightness of a pixel that is located in the vicinity of many edges. Conversely, a brightness with a small average edge level is considered to be the brightness of a pixel that has few edges nearby.

[0045] Fig. 7 is a diagram showing an example of a graph showing the average edge level for each brightness calculated in S504. In the example of Fig. 7, there are multiple maximum values. One of the maximum values ​​calculated here corresponds to the threshold value between the content area and the other area.

[0046] Next, in S505, the brightness corresponding to the maximum value is found from the average values ​​of the edge levels for each brightness found in S504 above.

[0047] Next, in S506, a brightness corresponding to a predetermined content rate is calculated based on the number of pixels for each brightness calculated in S502. The content rate indicates the ratio of content (data other than the background) to the input image. Specifically, a brightness X is calculated such that the number of pixels with a brightness of X or less is equal to or less than a predetermined content rate relative to the total number of pixels of the input image. Here, for example, the predetermined content rate is set to "20%". That is, when the content rate is "20%,", it means that 20% of the total pixels of the input image are pixels that represent text information or the like. In addition, when a content rate is set at a certain brightness, it indicates the ratio of brightnesses that are equal to or less than a certain brightness to the total number of pixels of the input image. That is, when a content rate of a brightness of "100" is set, it indicates the ratio of the number of pixels with a brightness of "100" or less to the total number of pixels of the input image, expressed as a percentage.

[0048] Next, in S507, the maximum value corresponding to the brightness that does not exceed the predetermined content rate is selected from the maximum values ​​obtained in S505, and its brightness is obtained. In this case, the brightness values ​​corresponding to the maximum values ​​obtained in S505 are compared with the brightness values ​​corresponding to the predetermined content rate in ascending order, and the maximum brightness that does not exceed the predetermined content rate is obtained. If there is no brightness value that does not exceed the predetermined content rate, the brightness corresponding to the first maximum value is selected. Here, in the example of FIG. 7, the predetermined content rate is set to "20%", so that the brightness X is "65". This is illustrated with the reference numeral 901. The predetermined content rate may differ depending on the document to be read. In the example of FIG. 7, the maximum value "624.887409" exists at the brightness "26", and the maximum value "485.550585" exists at the brightness "54", and the brightness corresponding to the predetermined content rate is "65". Therefore, the brightness "54" corresponds to the maximum maximum value that does not exceed the brightness "65" corresponding to the content rate "20%."

[0049] Next, in S508, the brightness calculated in S507 above is determined as the "brightness threshold for the entire image (T1 (first threshold))", and the average value of the edge level corresponding to the brightness is determined as the "edge level threshold (T2 (second threshold))". In the example of Fig. 7, the brightness "54" is determined as the "brightness threshold for the entire image (T1)", and the maximum value "485.550585" corresponding to the brightness "54" is determined as the "edge level threshold (T2)".

[0050] Next, in S509, the input image is binarized (binarization process) using the edge level data, the brightness threshold value (T1) for the entire image, and the edge level threshold value (T2). Details of this binarization process are shown in FIG.

[0051] The binarization process in S509 will be described in detail below with reference to Fig. 6. First, in S601, one unprocessed target pixel is selected from the input image in a predetermined order (hereinafter referred to as the "pixel of interest"), and the process proceeds to S602.

[0052] In S602, the edge level of the pixel of interest is compared with the edge level threshold (T2) to determine whether the pixel of interest is an edge portion near an edge or a non-edge portion. If the edge level of the pixel of interest is determined to be less than the edge level threshold (T2) (No in S602), the pixel of interest is determined to be a non-edge portion, and the process proceeds to S603.

[0053] In S603, the brightness of the pixel of interest is compared with the brightness threshold value (T1) for the entire image. If it is determined that the brightness of the pixel of interest is less than the brightness threshold value (T1) for the entire image (No in S603), the process proceeds to S604.

[0054] In S604, the pixel of interest is determined to be "black," a value corresponding to "black" is stored in the output RAM, and the process proceeds to S610.

[0055] On the other hand, in the above S603, if it is determined that the brightness of the pixel of interest is equal to or greater than the brightness threshold value (T1) for the entire image (Yes in S603), the process proceeds to S605.

[0056] In S605, the pixel of interest is determined to be "white," a value corresponding to "white" is stored in the output RAM, and the process proceeds to S610.

[0057] Furthermore, in the above S602, if it is determined that the edge level of the pixel of interest is equal to or greater than the edge level threshold value (T2) (Yes in S602), it is determined that the pixel of interest is an edge portion, and the process proceeds to S606.

[0058] In S606, the brightness of pixels within a specified range around the pixel of interest (e.g., 7 x 7 pixels) is referenced, and a value (third threshold) is calculated based on the maximum and minimum brightness values ​​and the ratio obtained based on the line width adjustment value entered using Figure 4.

[0059] For example, the line width adjustment value is set to 9 levels from 1 to 9, with 1 being the thinnest setting value and 9 being the thickest setting value. This value is called n. Also, the maximum and minimum values ​​obtained in S606 are called V max,V min , when the third threshold is T3

[0060] T3 = (V max × n + V min × (10 - n) / 10

[0061] By doing this, the smaller the line width adjustment value n, the smaller T3 becomes, and the larger n, the larger T3 becomes.

[0062] Next, in S607, the brightness of the pixel of interest is compared with the average value T3 calculated in S606. If it is determined that the brightness of the pixel of interest is equal to or lower than the average value T3 (No in S607), the process proceeds to S608.

[0063] In S608, the pixel of interest is determined to be "black," a value corresponding to "black" is stored in the output RAM, and the process proceeds to S610.

[0064] On the other hand, in S607, if it is determined that the brightness of the pixel of interest is greater than the average value T3 (Yes in S607), the process proceeds to S609.

[0065] In S609, the pixel of interest is determined to be "white," a value corresponding to "white" is stored in the output RAM, and the process proceeds to S610.

[0066] In S610, it is determined whether the processes in S601 to S609 have been performed for all pixels of the input image. If it is determined that there are still unprocessed pixels (No in S610), the process returns to S601 and proceeds to the process of the next pixel.

[0067] On the other hand, in the above S610, if it is determined that all pixels of the input image have been processed (Yes in S610), the process proceeds to S611.

[0068] In S611, the binary image data stored in the RAM is output, and this binarization process ends.

[0069] In this way, the line width can be adjusted by setting the threshold value of the pixel determined to be an edge portion as a weighted average of the maximum and minimum line width adjustment values. Also, by setting the threshold value so as not to exceed the range of the maximum or minimum values, it is possible to prevent the line from disappearing completely or becoming crushed black. Note that using the weighted average is just one example, and as described above, by setting the third threshold value T3 based on the maximum and minimum values ​​of the surrounding pixels and the thickness adjustment value, binarized data reflecting the desired line width can be obtained.

[0070] In this embodiment, the thresholds T1 and T2 are determined using the maximum value that does not exceed a specified content rate and its corresponding brightness. However, it is also possible to determine the thresholds T1 and T2 using the brightness corresponding to the maximum value that is closest to the brightness corresponding to the specified content rate.

[0071] A fixed value may be used for the predetermined content rate, or a setting means may be provided for allowing the user to select a type of document, such as a slip, a check, or a form, and setting the predetermined content rate, for example, 20% when a slip is selected, 15% when a check is selected, and 25% when a form is selected. The predetermined content rate for each type of document may be configured to be adjustable by the user. Specifically, the user may select an operation mode for reading a document using an image reading device to start reading the document, and at that time, the content rate according to the selected operation mode may be automatically set, or may be configured to be adjustable by the user. Also, the type of document may be determined from an input image, and the predetermined content rate may be determined based on the determined document type.

[0072] The third threshold T3 may be calculated after correcting the line width adjustment value n according to the predetermined content ratio and operation mode. The line width adjustment value n may also be corrected according to other settings such as the paper size and resolution set in FIG. 4, or may be corrected in combination with these.

[0073] Furthermore, the line width adjustment value n is not necessarily limited to being selected by the user, but may be configured to be automatically set based on other setting values ​​such as the operation mode.

[0074] The above processing allows flexible handling of documents of all types and conditions, and allows obtaining appropriate binary images even for documents with wrinkles, dirt, or faint text or other content. In addition, by using data with a lower resolution than the original input image when generating thresholds T1 and T2, the amount of processing can be reduced.

[0075] In this embodiment, the range of the pixel neighborhood is set to 7×7 with the pixel of interest at the center, but the size of this neighborhood may be variable. For example, a threshold determined by the user may be used, or other methods may be used as long as a similar calculation is possible using pixel values ​​around the target pixel. Also, switching may be performed according to the resolution of the input image. Since the expected line width and the blurring of the line boundary change depending on the type and resolution of the document, the thickening of characters can be appropriately processed to better suit the user's intention.

[0076] Furthermore, when changing the line width adjustment value using the screen shown in Fig. 4 or the like, an image sample of the binarized image to be output may be displayed in accordance with the adjustment of the line width adjustment value using the slider shown in Fig. 4. At that time, it is preferable to compare the results before and after binarization side by side.

[0077] In the present invention, the above-mentioned image processing is explained in an image processing unit that executes the application explained using Figure 4, but the image processing unit may be provided inside the scanner 100 or in the PC 200, and in either case, a device having an image processing unit functions as an image processing device. [Explanation of symbols]

[0078] 100 Scanner 200 PC 302 Image Processing Unit T1 Brightness threshold for the entire image (first threshold) T2 Edge level threshold (second threshold) T3: A value based on the maximum and minimum values ​​of the pixels surrounding the pixel of interest and the ratio obtained based on the line width adjustment value (third threshold)

Claims

1. an edge determination unit that determines whether each pixel in an image obtained by reading an original is an edge portion; a binarization processing unit that binarizes the image; Equipped with The binarization processing unit includes: a threshold value for binarizing pixels determined not to be edges by the edge determination unit is calculated from the entire image; 2. An image processing apparatus comprising: a pixel determining unit for determining whether a pixel is an edge; a threshold value for binarizing the pixel determined to be an edge in the edge determining unit; a line width adjustment value for adjusting a line width of the pixel;

2. The image processing device according to claim 1, characterized in that the binarization processing unit calculates a threshold value for a pixel determined to be an edge in the edge determination unit by calculating a weighted average of the maximum and minimum pixel values ​​in the vicinity of the target pixel in a ratio corresponding to the line width adjustment value.

3. The image processing apparatus according to claim 1 , wherein the range of the neighborhood of the target pixel is set by a user.

4. The binarization processing unit includes:

2. The image processing apparatus according to claim 1, wherein when calculating a threshold value for a pixel determined to be an edge in the edge determination section, a ratio corresponding to the line width adjustment value is corrected based on a setting when the document is read.

5. A display unit for displaying a sample image after the binarization process is provided; 2. The image processing apparatus according to claim 1, wherein the image to be displayed on the display unit is switched in accordance with a set value of the line width adjustment value.

Images