Image processing method and image reading device

Abstract

To enable automatic determination of a model of a white light source or an image sensor unit so that parameters relating to processing of read image data can be correctly set.SOLUTION: A processor 51 acquires test image data being read image data obtained by an image reading device 10 for a test image medium including a test region of a specific color (S102). The processor 51 derives a blue representative value being a representative value of blue data, and a determination color representative value being a representative value of red or green data, for a plurality of pieces of pixel data in the test region of the test image data (S103). The processor 51 derives a determination value by correcting the determination color representative value according to a ratio of a blue reference value to the blue representative value (S104). The processor 51 determines a model of the white light source by comparing the determination value with a determination reference value (S105).SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to an image processing method and an image reading device that can determine the model of a white light source or an image sensor unit. [Background technology]

[0002] The image reading device includes a white light source, an image sensor unit, and an image data output unit. Light emitted from the white light source is irradiated onto an image medium such as a document. The image sensor unit receives the reflected light from the light irradiated onto the image medium and outputs an image signal corresponding to the amount of light received.

[0003] The image data output unit digitizes the image signal to output read image data, which includes a plurality of pixel data for each of the three primary colors of red, green, and blue.

[0004] It is also known that the image reading device reads a test image for adjustment and adjusts parameters relating to processing of the read image data based on the read image data of the test image (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2002-171417 Public Relations Summary of the Invention [Problem to be solved by the invention]

[0006] Incidentally, there are cases where the model of the white light source or the image sensor unit attached to the image reading device is changed.

[0007] For example, in the manufacturing process of the image reading device, the model of the white light source or the image sensor unit attached to the image reading device may be changed to a model that is easier to procure.

[0008] Furthermore, when the image reading device is repaired, the white light source or the image sensor unit may be replaced from the model already equipped with the image reading device to a model that is in stock.

[0009] In the image reading device, when the model of the white light source or the image sensor unit is changed, the setting of parameters related to the processing of the read image data needs to be changed.

[0010] An object of the present invention is to provide an image processing method and an image reading device that can automatically determine the type of white light source or image sensor unit so that parameters related to the processing of read image data can be set correctly. [Means for solving the problem]

[0011] An image processing method according to one aspect of the present invention is a method for processing read image data obtained by an image reading device. The image reading device includes a white light source, an image sensor unit, and an image data output unit. The image sensor unit receives reflected light from the white light source irradiated onto an image medium and outputs an image signal corresponding to the amount of received light. The image data output unit digitizes the image signal to output read image data including multiple pixel data for each of the three primary colors of red, green, and blue. The image processing method includes a processor acquiring test image data, which is the read image data obtained by the image reading device for a test image medium including a test area of a specific color. The image processing method further includes the processor deriving a blue representative value that is a representative value of blue data and a judgment color representative value that is a representative value of red or green data for the multiple pixel data of the test area in the test image data. The image processing method further includes the processor deriving a judgment value by correcting the judgment color representative value according to a ratio of a predetermined blue reference value to the blue representative value. The image processing method further includes the processor determining the type of the white light source by comparing the determination value with a preset reference value.

[0012] An image processing method according to another aspect of the present invention is a method for processing the scanned image data obtained by the image reading device. The image processing method includes a processor deriving corrected test image data by applying shading correction to the scanned image data obtained by the image reading device for a test image medium including a test area of a specific color. The image processing method further includes the processor deriving a judgment color representative value, which is a representative value of data of a predetermined judgment color among the plurality of pixel data of the test area in the corrected test image data. The image processing method further includes the processor determining the model of the white light source or the image sensor unit by comparing the judgment color representative value with a predetermined judgment reference value.

[0013] An image reading device according to another aspect of the present invention includes the white light source, the image sensor unit, the image data output section, and the processor that implements the image processing method. [Effects of the Invention]

[0014] According to the present invention, it is possible to provide an image processing method and an image reading device that can automatically determine the type of white light source or image sensor unit so that parameters related to the processing of read image data are correctly set. [Brief explanation of the drawings]

[0015] [Figure 1] FIG. 1 is a diagram showing the configuration of an image reading apparatus according to an embodiment. [Figure 2] FIG. 2 is a configuration diagram of an image reading unit in the image reading apparatus according to the embodiment. [Figure 3] FIG. 3 is a block diagram showing the configuration of a control device in the image reading device according to the embodiment. [Figure 4] FIG. 4 is a flowchart showing the procedure of a first example of a parameter setting process in the image reading device according to the embodiment. [Figure 5] FIG. 5 is a flowchart showing the procedure of a second example of the parameter setting process in the image reading device according to the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0016] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Note that the following embodiment is an example of the present invention, and does not limit the technical scope of the present invention.

[0017] [Configuration of image reading device 10] An image reading device 10 according to the embodiment reads an image formed on an image medium 9 such as a document, and outputs image data representing the read image.

[0018] 1, the image reading device 10 includes a main body 101 and a cover 102 that covers part or all of the top surface of the main body 101. The cover 102 is supported on the top surface of the main body 101 so as to be openable and closable.

[0019] The image reading device 10 further includes an image reading unit 1, a scanning mechanism 2, a platen glass 3, an AFE (Analog Front End) 4, and a control device 5. The image reading unit 1, the scanning mechanism 2, the AFE 4, and the control device 5 are arranged in a main body 101.

[0020] The platen glass 3 is disposed on the upper surface of the main body 101. An image medium 9 such as a document is placed on the platen glass 3. When the cover 102 is closed, the cover 102 covers the upper surface of the platen glass 3 on which the image medium 9 is placed.

[0021] The image reading device 10 further includes an operation device 501 and a display device 502 disposed on the main body 101 .

[0022] The image reading unit 1 reads a line image from the image medium 9 while irradiating light onto the image medium 9 on the platen glass 3. The scanning mechanism 2 causes the image reading unit 1 to scan the image medium 9 on the platen glass 3. The scanning mechanism 2 includes a carriage 21 and a moving mechanism 22.

[0023] The carriage 21 supports the image reading unit 1. The movement mechanism 22 moves the carriage 21 along the platen glass 3. As the movement mechanism 22 moves the carriage 21, the image reading unit 1 scans along the image medium 9 on the platen glass 3.

[0024] The image reading unit 1 is disposed with its longitudinal direction aligned with the main scanning direction D1. That is, the image reading unit 1 extends in the main scanning direction D1. The image reading unit 1 is scanned by the scanning mechanism 2 in the sub-scanning direction D2.

[0025] As shown in FIG. 2, the image reading unit 1 includes a white light source 11 and an image sensor unit 12 .

[0026] The white light source 11 emits white light. The light emitted from the white light source 11 is irradiated onto the surface of the image medium 9. In the example shown in Fig. 2, the white light source 11 is formed to extend in the main scanning direction D1, and the light emitted from the white light source 11 is directly irradiated onto the surface of the image medium 9.

[0027] Alternatively, the white light source 11 may emit light from an end of a light guiding member arranged along the main scanning direction D1. In this case, the light emitted from the white light source 11 is irradiated onto the surface of the imaging medium 9 through the light guiding member.

[0028] The image sensor unit 12 includes an image sensor 121 arranged along the main scanning direction D1. The image sensor 121 receives reflected light of the light from the white light source 11 irradiated onto the imaging medium 9, and outputs an image signal AS1 corresponding to the amount of received light. The image sensor unit 12 is a so-called line sensor unit.

[0029] The image sensor 121 includes a red image sensor 121R, a green image sensor 121G, and a blue image sensor 121B that detect the amounts of light of the three primary colors of red, green, and blue, respectively, in the reflected light.

[0030] 2, the image sensor unit 12 includes a spectrometer 122 that splits the reflected light into the three primary color lights. The red image sensor 121R, the green image sensor 121G, and the blue image sensor 121B receive the red light, the green light, and the blue light split by the spectrometer 122, respectively.

[0031] The AFE 4 digitizes the image signal AS1 to output read image data DT1 including multiple pixel data for each of the three primary colors of red, green, and blue. The read image data DT1 is transmitted to the control device 5. The AFE 4 is an example of an image data output unit that outputs the read image data DT1.

[0032] The image reading device 10 further includes a frame member 103 disposed on the upper surface of the main body 101. The frame member 103 forms the outer edge of a medium placement area on the platen glass 3 where an image medium 9 can be placed.

[0033] The image reading device 10 further includes a white reference portion 31 and a black reference portion 32 disposed on the lower surface of the frame member 103. The white reference portion 31 has a uniform white lower surface, and the black reference portion 32 has a uniform black lower surface.

[0034] The white reference portion 31 and the black reference portion 32 are disposed on one side of the medium placement area in the sub-scanning direction D2.

[0035] The scanning mechanism 2 can move the image reading unit 1 to below each of the white reference portion 31 and the black reference portion 32 and below the medium placement area of the platen glass 3. By being positioned below the white reference portion 31 or the black reference portion 32, the image reading unit 1 can read the white reference image of the white reference portion 31 or the black reference image of the black reference portion 32.

[0036] The data of the white reference image read from the white reference portion 31 and the data of the black reference image read from the black reference portion 32 are used for shading correction of the read image data DT1.

[0037] The operation device 501 accepts operations by a person. For example, the operation device 501 includes one or both of a touch panel and one or more operation buttons. The display device 502 can display various types of information. For example, the display device 502 is a panel display device such as a liquid crystal panel unit.

[0038] [Control device 5] The control device 5 performs various data processing and controls the devices included in the image reading device 10.

[0039] 3, the control device 5 includes a CPU (Central Processing Unit) 51, and peripheral devices such as a RAM (Random Access Memory) 52, a secondary storage device 53, and a signal interface 54. The control device 5 further includes a communication device 55.

[0040] The CPU 51 is a processor that executes computer programs to perform various data processing and control operations, and is an example of a processor that controls the image reading device 10 and processes the read image data DT1.

[0041] The RAM 52 is a computer-readable volatile storage device that temporarily stores the computer programs executed by the CPU 51 and data that is output and referenced by the CPU 51 during the course of executing various processes.

[0042] The secondary storage device 53 is a non-volatile storage device that can be read by a computer. The secondary storage device 53 can store and update the computer programs and various data. For example, a flash memory or a hard disk drive, or both, may be used as the secondary storage device 53.

[0043] The signal interface 54 converts signals output by various sensors into digital data and transmits the converted digital data to the CPU 51. Furthermore, the signal interface 54 converts control commands output by the CPU 51 into control signals and transmits the control signals to the devices to be controlled.

[0044] The communication device 55 can communicate with a host device (not shown) and other devices. The host device is an information processing device such as a personal computer or a smartphone operated by a user.

[0045] The CPU 51 receives a processing request from the host device through the communication device 55. The processing request is a data transmission request, a data storage request, or the like.

[0046] The data transmission request is a request for processing to read an image from the image medium 9 and transmit the read image data DT1 or data in a specified format obtained by converting the read image data DT1 into a specified data format to a specified destination.

[0047] The data saving request is a request for processing to read an image from the image medium 9 and save the read image data DT 1 or the specified format data in the secondary storage device 53 .

[0048] The CPU 51 includes a plurality of processing modules that are realized by executing the computer programs, including a main control unit 5a and an image processing unit 5b.

[0049] The main control unit 5a executes control to start various processes in response to processing requests input through the operation device 501 or the communication device 55, and controls the display device 502, etc.

[0050] Furthermore, the main control unit 5a controls the white light source 11 and the image sensor unit 12 of the image reading unit 1, and also controls the scanning mechanism 2. causes the image reading unit 1 and the scanning mechanism 2 to perform an image reading process for reading an image from the image medium 9.

[0051] The image processing unit 5b performs various image processing on the read image data DT1, such as shading correction, tone correction, and color correction, on the read image data DT1.

[0052] Furthermore, the image processing unit 5b generates the specified format data by converting the corrected scanned image data DT1 into a specified data format, which is selected from a number of options such as PDF, GIF, or PNG.

[0053] Note that some or all of the plurality of processing modules may be realized by a DSP (Digital Signal Processor) or an ASIC (Application Specific Integrated Circuit).

[0054] Incidentally, there are cases where the model of the white light source 11 or the image sensor unit 12 attached to the image reading device 10 is changed.

[0055] For example, in the manufacturing process of the image reading device 10, the model of the white light source 11 or the image sensor unit 12 attached to the image reading device 10 may be changed to a model that is easier to procure.

[0056] Furthermore, when the image reading device 10 is repaired, the white light source 11 or the image sensor unit 12 may be replaced from the model already equipped with it to a model that is in stock.

[0057] In the image reading device 10, when the model of the white light source 11 or the image sensor unit 12 is changed, the setting of parameters related to the processing of the read image data DT1 needs to be changed.

[0058] In the image reading device 10, the CPU 51 further includes an adjustment unit 5c as one of the plurality of processing modules. The adjustment unit 5c executes a parameter setting process, which will be described later (see FIGS. 4 and 5).

[0059] The parameter setting process includes a process of automatically determining the model of the white light source 11 or the image sensor unit 12 so that parameters related to the processing of the read image data DT1 are set correctly.

[0060] In the following description, the parameters related to the processing of the scanned image data DT1 set in the parameter setting process are referred to as image processing parameters PT1 (see FIG. 3). The image processing parameters PT1 are recorded in the secondary storage device 53.

[0061] [First example of parameter setting process] The procedure of the first example of the parameter setting process will be described below with reference to the flowchart shown in FIG.

[0062] The first example of the parameter setting process is an example of a process that realizes an image processing method for processing read image data DT1 obtained by the image reading device 10. The CPU 51 is an example of a processor that realizes the image processing method.

[0063] The adjustment unit 5c executes the parameter setting process when an adjustment request is input via the operation device 501 or the communication device 55. The adjustment request is input when the assembly of the image reading device 10 is completed or when the white light source 11 of the image reading device 10 is replaced.

[0064] As will be described later, the first example of the parameter setting process includes a process of determining the model of the white light source 11 and a process of setting parameters related to the processing of the read image data DT1 according to the determination result.

[0065] In the following description, S101, S102, ... represent identification symbols of a plurality of steps in the first example of the parameter setting process. In the first example of the parameter setting process, the process of step S101 is executed first.

[0066] <Process S101> In step S101, the adjustment section 5c causes the image reading unit 1 to execute a process of reading an image of a test image medium prepared in advance. The test image medium includes a test area, which is an area of a predetermined specific color.

[0067] For example, the process of step S101 is performed under the condition that the test image medium is placed on the platen glass 3 and the cover 102 is closed. Alternatively, the test image medium may be placed next to the white reference portion 31 and the black reference portion 32 on the lower surface of the frame member 103.

[0068] For example, the specific color in the first example is white. In this case, a white reference portion 31 may be used as the test image medium. Also, the specific color in the first example may be an achromatic color other than white, such as gray.

[0069] After performing the process of step S101, the adjustment unit 5c performs the process of step S102.

[0070] <Process S102> In step S102, the adjustment unit 5c acquires test image data, which is read image data DT1 obtained by the image reading unit 1 for the test image medium.

[0071] After performing the process of step S102, the adjustment unit 5c performs the process of step S103.

[0072] <Process S103> In step S103, the adjustment unit 5c derives a blue representative value, which is a representative value of blue data, and a judgment color representative value, which is a representative value of data of judgment colors other than blue, for the plurality of pixel data of the test region in the test image data. The judgment colors are red or green.

[0073] For example, the representative value may be a mean value. Alternatively, the representative value may be a median value.

[0074] After executing the process of step S103, the adjustment unit 5c executes the process of step S104.

[0075] <Process S104> In step S104, the adjustment unit 5c derives a judgment value by correcting the judgment color representative value in accordance with the ratio of a preset blue reference value to the blue representative value.

[0076] For example, if the blue representative value is 60 and the blue reference value is 255, the ratio of the blue reference value to the blue representative value is 4.25. In this case, the adjustment unit 5c multiplies the judgment color representative value by 4.25 to derive the value obtained as the judgment value.

[0077] The blue representative value is an index value of the light intensity of the white light source 11. The process of step S104 is a process for reducing the influence of variations in the light intensity of the white light source 11 on the judgment color representative value.

[0078] After executing the process of step S104, the adjustment unit 5c executes the process of step S105.

[0079] <Process S105> In step S105, the adjustment unit 5c determines the model of the white light source 11 by comparing the determination value derived in step S104 with a preset determination reference value.

[0080] The judgment reference value is a threshold value for distinguishing between multiple candidate models of the white light source 11. When there are two candidate models of the white light source 11, the judgment reference value is one. When there are three candidate models of the white light source 11, the judgment reference value is two.

[0081] A model determination rule is set in advance, which indicates the correspondence relationship between a plurality of candidate models of the white light source 11 and the range of the determination value with the determination reference value as a threshold value. The adjustment unit 5c determines the model of the white light source 11 in accordance with the model determination rule.

[0082] After executing the process of step S105, the adjustment unit 5c executes the process of step S106.

[0083] <Process S106> In step S106, the adjustment unit 5c sets the image processing parameters PT1 in the image reading device 10 according to the determination result of the model of the white light source 11.

[0084] Parameter selection rules are set in advance to represent the correspondence between multiple candidate models of white light source 11 and multiple candidate image processing parameters PT1. Adjustment unit 5c sets image processing parameters PT1 in accordance with the parameter selection rules. Adjustment unit 5c records the setting results of image processing parameters PT1 in secondary storage device 53.

[0085] After executing the process of step S106, the adjustment unit 5c ends the parameter setting process. The adjustment unit 5c processes the read image data DT1 using the image processing parameters PT1 set by the parameter setting process.

[0086] For example, the image processing parameters PT1 include one or both of function setting parameters and character image processing parameters. The function setting parameters include color discrimination parameters used to discriminate the color of each pixel data in the scanned image data DT1. The character image processing parameters are parameters used in character recognition processing of the scanned image data DT1.

[0087] In this embodiment, the white light source 11 is an LED light source including a blue light emitter and a yellow phosphor covering the blue light emitter. The light from the blue light emitter becomes white light by passing through the yellow phosphor.

[0088] The characteristics of the light emitted from the white light source 11 are determined mainly by the characteristics of the yellow phosphor. The characteristics of the yellow phosphor are mainly reflected in the red or green light component, which is the determined color. The light amount of the white light source 11 is mainly reflected in the value of the blue data in the read image data DT1.

[0089] Therefore, by adopting the first example of the parameter setting process, the influence of variations in the light intensity of the white light source 11 is reduced, and the model of the white light source 11 is automatically determined with high accuracy.

[0090] Furthermore, the model of the white light source 11 is automatically determined, so that the image processing parameter PT1 is set correctly.

[0091] [Second example of parameter setting process] Next, the procedure of a second example of the parameter setting process will be described with reference to the flowchart shown in FIG.

[0092] The second example of the parameter setting process is an example of a process that realizes an image processing method for processing read image data DT1 obtained by the image reading device 10. The CPU 51 is an example of a processor that realizes the image processing method.

[0093] The adjustment unit 5c executes the parameter setting process when an adjustment request is input via the operation device 501 or the communication device 55. The adjustment request is input when the assembly of the image reading device 10 is completed or when the white light source 11 or the image sensor unit 12 of the image reading device 10 is replaced.

[0094] As will be described later, the second example of the parameter setting process includes a process of determining the model of the image sensor unit 12, and a process of setting image processing parameters PT1 related to the processing of the read image data DT1 according to the determination result.

[0095] Hereinafter, the image sensor unit 12 that is the target of model determination in the second example of the parameter setting process will be referred to as the “target part.” The adjustment request is input when the assembly of the image reading device 10 is completed or when the target part of the image reading device 10 is replaced.

[0096] In the following description, S201, S202, ... represent identification symbols of a plurality of steps in the second example of the parameter setting process. In the second example of the parameter setting process, the process of step S201 is executed first.

[0097] <Process S201> In step S201, the adjustment section 5c causes the scanning mechanism 2 and the image reading unit 1 to execute a process of reading the white reference portion 31 and the black reference portion 32, respectively.

[0098] The adjustment unit 5c executes the process of step S202 while executing the process of step S201.

[0099] <Process S202> In step S202, the adjusting section 5c obtains the white reference data and the black reference data, which are the read image data DT1 obtained by the image reading unit 1 for the white reference portion 31 and the black reference portion 32, respectively.

[0100] After executing the process of step S202, the adjustment unit 5c executes the process of step S203.

[0101] <Process S203> In step S203, the adjustment section 5c causes the image reading unit 1 to execute a process of reading an image of the test image medium prepared in advance. The test image medium includes a test area, which is an area of a predetermined specific color.

[0102] For example, the process of step S203 is performed under the condition that the test image medium is placed on the platen glass 3 and the cover 102 is closed. Alternatively, the test image medium may be placed next to the white reference portion 31 and the black reference portion 32 on the lower surface of the frame member 103.

[0103] For example, the specific color in the second example is yellow or magenta.

[0104] The adjustment unit 5c executes the process of step S204 while executing the process of step S203.

[0105] <Process S204> In step S204, the adjustment unit 5c acquires test image data, which is the read image data DT1 obtained by the image reading unit 1 for the test image medium.

[0106] After executing the process of step S204, the adjustment unit 5c executes the process of step S205.

[0107] <Process S205> In step S205, the adjustment unit 5c performs shading correction on the test image data obtained in step S204 to derive corrected test image data.

[0108] In step S205, the adjustment unit 5c performs the shading correction using the white reference data and the black reference data obtained in step S202. The shading correction parameters used in the shading correction in step S205 are parameters common to multiple candidates for the model of the target part.

[0109] After executing the process of step S205, the adjustment unit 5c executes the process of step S206.

[0110] <Process S206> In step S206, the adjustment unit 5c derives a judgment color representative value that is a representative value of data of a preset judgment color among the plurality of pixel data of the test region in the corrected test image data.

[0111] For example, if the specific color is yellow, blue is used as the judgment color, if the specific color is magenta, green is used as the judgment color, and if the specific color is cyan, red is used as the judgment color.

[0112] That is, the combination of the specific color and the judgment color is a combination of yellow and blue, a combination of magenta and green, or a combination of cyan and red.

[0113] Magenta and green are complementary colors. Cyan and red are also complementary colors. Yellow and blue are also roughly complementary colors.

[0114] For example, the representative value may be a mean value. Alternatively, the representative value may be a median value.

[0115] After executing the process of step S206, the adjustment unit 5c executes the process of step S207.

[0116] <Process S207> In step S207, the adjustment unit 5c judges the model of the target part by comparing the judgment color representative value derived in step S206 with a preset judgment reference value.

[0117] The judgment reference value is a threshold value for distinguishing between multiple candidate models of the target part. When there are two candidate models of the target part, the judgment reference value is 1. When there are three candidate models of the target part, the judgment reference value is 2.

[0118] A model determination rule is set in advance, which indicates a correspondence relationship between a plurality of candidate model types of the target part and the range of the judgment color representative value with the judgment reference value as a threshold value. The adjustment unit 5c determines the model of the target part in accordance with the model determination rule.

[0119] After executing the process of step S207, the adjustment unit 5c executes the process of step S208.

[0120] <Process S208> In step S208, the adjustment unit 5c sets the image processing parameters PT1 in the image reading device 10 according to the determination result of the model of the target part.

[0121] Parameter selection rules are set in advance to represent the correspondence between a plurality of candidate model types of the target part and a plurality of candidate image processing parameters PT1. Adjustment unit 5c sets image processing parameters PT1 in accordance with the parameter selection rules. Adjustment unit 5c records the setting results of image processing parameters PT1 in secondary storage device 53.

[0122] After executing the process of step S208, the adjustment unit 5c ends the parameter setting process. The adjustment unit 5c processes the read image data DT1 using the image processing parameters PT1 set by the parameter setting process.

[0123] As described above, the characteristics of the light emitted from the white light source 11 are mainly reflected in the red or green light component. In the second example, the red or green light component is reflected in the light reflected in the test area of the specific color, magenta or yellow.

[0124] In the second example, the influence of variations in the amount of light from the white light source 11 is reduced by the shading correction.

[0125] By adopting the second example of the parameter setting process, the model of the image sensor unit 12 is automatically determined with high accuracy.

[0126] Furthermore, the model of the white light source 11 or the image sensor unit 12 is automatically determined, so that the image processing parameter PT1 is set correctly.

[0127] In the second example of the parameter setting process, the target part may be a white light source 11. In this case, the specific color may be magenta, and the judgment color may be red.

[0128] [Notes on the Invention] The following is a summary of the invention extracted from the above-described embodiment. Note that the configurations and processing functions described in the following supplementary notes can be selected and combined as desired.

[0129] <Appendix 1> An image processing method for processing read image data obtained by an image reading device including: a white light source; an image sensor unit that receives reflected light of the light from the white light source irradiated onto an image medium and outputs an image signal corresponding to the amount of received light; and an image data output unit that outputs read image data including a plurality of pixel data for each of the three primary colors of red, green, and blue by digitizing the image signal, the method comprising: A processor acquires test image data, which is the scanned image data obtained by the image scanning device for a test image medium including a test area of a specific color; The processor derives a blue representative value that is a representative value of blue data and a judgment color representative value that is a representative value of red or green data for the plurality of pixel data of the test area in the test image data; the processor deriving a judgment value by correcting the judgment color representative value according to a ratio of a preset blue reference value to the blue representative value; and determining the model of the white light source by comparing the determination value with a preset reference value.

[0130] <Appendix 2> 2. The image processing method according to claim 1, wherein the specific color is white.

[0131] <Appendix 3> The image processing method described in Appendix 1 or Appendix 2, further comprising the processor setting parameters related to processing of the read image data in the image reading device according to the result of determining the model of the white light source.

[0132] <Appendix 4> An image processing method for processing read image data obtained by an image reading device including: a white light source; an image sensor unit that receives reflected light of the light from the white light source irradiated onto an image medium and outputs an image signal corresponding to the amount of received light; and an image data output unit that outputs read image data including a plurality of pixel data for each of the three primary colors of red, green, and blue by digitizing the image signal, the method comprising: a processor performing shading correction on the scanned image data obtained by the image scanning device for a test image medium including a test area of a specific color, thereby deriving corrected test image data; the processor deriving a judgment color representative value that is a representative value of data of a predetermined judgment color among the plurality of pixel data of the test region in the corrected test image data; and determining the model of the white light source or the image sensor unit by comparing the determination color representative value with a preset determination reference value.

[0133] <Appendix 5> The object of the model determination is the image sensor unit, The image processing method according to claim 4, wherein the combination of the specific color and the judgment color is a combination of yellow and blue, a combination of magenta and green, or a combination of cyan and red.

[0134] <Appendix 6> The object of the model determination is the white light source, 5. The image processing method according to claim 4, wherein the combination of the specific color and the judgment color is a combination of magenta and red.

[0135] <Appendix 7> The image processing method described in any one of Supplementary Note 4 to Supplementary Note 6, further including the processor setting parameters related to the processing of the read image data in the image reading device according to the determination result of the model of the white light source or the image sensor unit.

[0136] <Appendix 8> A white light source; an image sensor unit that receives reflected light of the white light source irradiated onto an image medium and outputs an image signal corresponding to the amount of received light; an image data output unit that outputs read image data including a plurality of pixel data for each of the three primary colors of red, green, and blue by digitizing the image signal; An image reading device comprising: a processor that implements the image processing method according to any one of Supplementary Note 1 to Supplementary Note 7. [Explanation of symbols]

[0137] 1: Image reading unit 2: Scanning mechanism 3: Platen glass 5: Control device 10: Image reader 11: White light source 12: Image sensor unit 51: CPU (processor) 121: Image sensor 121B: Blue image sensor 121G: Green image sensor 121R: Red image sensor 122: Spectrometer AS1: Image signal DT1: Scanned image data PT1: Image processing parameters

Claims

1. An image processing method for processing read image data obtained by an image reading device including: a white light source; an image sensor unit that receives reflected light of the light from the white light source irradiated onto an image medium and outputs an image signal corresponding to the amount of received light; and an image data output unit that outputs read image data including a plurality of pixel data for each of the three primary colors of red, green, and blue by digitizing the image signal, A processor acquires test image data, which is the scanned image data obtained by the image scanning device for a test image medium including a test area of a specific color; The processor derives a blue representative value that is a representative value of blue data and a judgment color representative value that is a representative value of red or green data for the plurality of pixel data of the test area in the test image data; the processor deriving a judgment value by correcting the judgment color representative value according to a ratio of a preset blue reference value to the blue representative value; and determining the model of the white light source by comparing the determination value with a preset reference value.

2. The image processing method according to claim 1 , wherein the specific color is white or an achromatic color other than white.

3. The image processing method according to claim 1 , further comprising the processor setting parameters relating to processing of the scanned image data in the image scanning device in accordance with the result of determining the model of the white light source.

4. An image processing method for processing read image data obtained by an image reading device including: a white light source; an image sensor unit that receives reflected light of the light from the white light source irradiated onto an image medium and outputs an image signal corresponding to the amount of received light; and an image data output unit that outputs read image data including a plurality of pixel data for each of the three primary colors of red, green, and blue by digitizing the image signal, a processor performing shading correction on the scanned image data obtained by the image scanning device for a test image medium including a test area of a specific color, thereby deriving corrected test image data; the processor deriving a judgment color representative value that is a representative value of data of a predetermined judgment color among the plurality of pixel data of the test region in the corrected test image data; and determining the model of the white light source or the image sensor unit by comparing the determination color representative value with a preset determination reference value.

5. The object of the model determination is the image sensor unit, 5. The image processing method according to claim 4, wherein the combination of the specific color and the judgment color is a combination of yellow and blue, a combination of magenta and green, or a combination of cyan and red.

6. The object of the model determination is the white light source, The image processing method according to claim 4 , wherein the combination of the specific color and the judgment color is a combination of magenta and red.

7. The image processing method according to claim 4 , further comprising the processor setting parameters relating to processing of the read image data in the image reading device according to the determination result of the model of the white light source or the image sensor unit.

8. A white light source; an image sensor unit that receives reflected light of the white light source irradiated onto an image medium and outputs an image signal corresponding to the amount of received light; an image data output unit that outputs read image data including a plurality of pixel data for each of the three primary colors of red, green, and blue by digitizing the image signal; An image reading device comprising: a processor that implements the image processing method according to any one of claims 1 to 7.

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