Image measurement apparatus and program

Abstract

Provided is an image measurement device capable of flexibly performing distortion correction in response to an environmental change. An image measuring apparatus according to the present invention comprises: a stage on which a measurement target is placed; a reference pattern display unit on which a reference pattern is displayed; an image capturing unit that captures an image of the object; a distortion information generating unit that generates distortion information based on the image of the reference pattern captured by the image capturing unit and design information of the reference pattern; and a correction unit that corrects the image of the measurement target captured by the image capturing unit using the distortion information.

Description

Technical Field

[0001] The present invention relates to an image measuring apparatus and a program for contactlessly measuring the shape of a measurement target based on an image obtained by capturing the measurement target. Background Art

[0002] An image measuring device is a device that captures an image of a measurement target (hereinafter referred to as a "workpiece"), analyzes the image, extracts shapes such as lines, circles, and polygons, and obtains measurement results such as distance, inclination, diameter, width, etc. of the extracted shapes.

[0003] When capturing images with a camera, if the captured image is distorted due to lens distortion or other factors, this distortion directly leads to a degradation in measurement accuracy. This requires high-precision optical design, but it is difficult to avoid residual distortion in the captured image due to factors such as lens manufacturing tolerances.

[0004] As a technique for addressing this issue, there is a known camera calibration technique that corrects residual distortion in an image based on distortion information obtained by comparing an image captured by a camera with the design values ​​of a reference pattern. Conventional vision measurement equipment often includes a function for correcting image distortion using this camera calibration technique (see, for example, Japanese Patent Laid-Open No. 2005-4391). Summary of the Invention

[0005] Problems to be solved by the present invention

[0006] The shapes of the camera lens and light-receiving element of an image measuring device are susceptible to environmental changes, such as temperature. Therefore, if the temperature changes after distortion information is acquired, or if the image measuring device is moved from the location where the distortion information was acquired, issues with the accuracy of the distortion information may arise. To ensure the accuracy of the correction, it is therefore preferable to obtain the distortion information again. However, to acquire distortion information and perform corrections during measurement, it is necessary to place a flat plate with a reference pattern engraved on it on the stage, capture an image of the flat plate, replace the plate with the measurement target, capture an image of the measurement target, and then perform the necessary operations to acquire distortion information. This is a time-consuming process, and it is difficult to perform flexible distortion correction in response to environmental changes.

[0007] An object of the present invention is to provide an image measuring apparatus and program that can flexibly perform distortion correction in response to environmental changes.

[0008] Means used to solve problems

[0009] An image measuring apparatus according to one aspect of the present invention includes: a stage on which a measurement target is placed; a reference pattern display unit on which a reference pattern is displayed; an image capturing unit that captures an image of the target; a distortion information generating unit that generates distortion information based on the image of the reference pattern captured by the image capturing unit and design information of the reference pattern; and a correction unit that corrects the image of the measurement target captured by the image capturing unit using the distortion information.

[0010] Effects of the Invention

[0011] The image measuring device of the present invention incorporates a built-in reference pattern, eliminating the need to replace the reference pattern on the stage with the measurement target even when acquiring distortion information and performing corrections during measurement. This reduces the effort required to acquire distortion information and enables flexible distortion correction in response to environmental changes. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 FIG. 1 shows a functional block diagram of a vision measuring device 100 according to the present invention.

[0013] Figure 2 FIG. 1 shows a functional block diagram of a vision measuring device 101 according to the present invention.

[0014] Figure 3 FIG. 1 shows a functional block diagram of the image measuring device 102 according to the present invention.

[0015] Figure 4 FIG. 1 shows a functional block diagram of the image measuring device 103 according to the present invention. DETAILED DESCRIPTION

[0016] [First embodiment]

[0017] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In the following description, parts that have already been described are denoted by the same reference numerals, and description thereof is omitted.

[0018] Figure 1 1 , a functional block diagram of a vision measuring device 100 according to a first embodiment is shown. The vision measuring device 100 includes a stage 110, a reference pattern display unit 120, a light source 130, an image capturing unit 140, an object switching unit 150, a distortion information generating unit 160, a correction unit 170, and a control unit 180.

[0019] The stage 110 is arranged so that its upper surface (mounting surface) is horizontal. The measurement target W is placed on the mounting surface. The stage 110 has a driving component for the horizontal direction, such as a motor and an actuator, and realizes two-dimensional movement under the control of the control unit 180.

[0020] The reference pattern is displayed on the reference pattern display unit 120. The display of the reference pattern is accomplished by engraving or depositing the reference pattern on the surface of a substrate such as flat glass.

[0021] The light source 130 is a light emitting component that irradiates light on the object at a brightness and position sufficient for image measurement and distortion correction when the image capturing unit 140 captures an image of the object. If natural light is sufficient to illuminate the object, the light source 130 does not have to be provided.

[0022] The image capturing unit 140 is a capturing member that captures an image of a measurement target and a reference pattern as an image object. The captured image may be temporarily or permanently stored in any type of storage medium.

[0023] For example, the object switching unit 150 may be configured to switch the object captured by the image capturing unit 140 when capturing each of the measurement target and the reference pattern.

[0024] The object switching unit 150 may include, for example, a beam splitter 151 that transmits incident light from the reference pattern display unit 120 and incident light from the measurement target W toward the image capture unit 140; a shutter 152 that is provided between the reference pattern display unit 120 and the beam splitter 151; and a shutter 153 that is provided between the measurement target W and the beam splitter 151. In this configuration, for example, when the image capture unit 140 captures a reference pattern, the shutter 152 is opened and the shutter 153 is closed; and when the measurement target W is captured, the shutter 152 is closed and the shutter 153 is opened.

[0025] The distortion information generation unit 160 generates distortion information based on the image of the reference pattern captured by the image capture unit 140 and the design information of the reference pattern that has been prepared in advance. Specifically, the size of the reference pattern read from the captured image is compared with the design size and the size tolerance, and the distortion information is generated based on the difference between them.

[0026] The correction unit 170 corrects the image of the measurement target W captured by the image capture unit 140 using the distortion information generated by the distortion information generation unit 160 .

[0027] The control unit 180 performs control based on information input by the operator or based on a program that describes the processing flow and the functions of each functional unit. The control unit 180 can be implemented by a personal computer, which includes, for example, a CPU that executes the program to implement the described functions, various storage components that temporarily or permanently store programs and data, various input components such as a keyboard and a mouse, various display components, and various communication components such as wired or wireless communication components.

[0028] Under the control of the control unit 180 , the correction process in the first embodiment is performed as follows, for example.

[0029] When the operator places the measurement target W on stage 110 and issues a command to control unit 180, control unit 180 performs correction processing by controlling each functional unit according to the processing flow described in the program. Specifically, first, shutter 152 is opened and shutter 153 is closed, and then image capture unit 140 is caused to capture an image to obtain an image of the reference pattern. Alternatively, shutter 152 is closed and shutter 153 is opened, and then image capture unit 140 is caused to capture an image to obtain an image of the measurement target W. Each captured image can be stored in a suitable storage device. Next, distortion information generation unit 160 generates distortion information based on the image of the reference pattern and pre-prepared design information for the reference pattern. Correction unit 170 then uses the distortion information generated by distortion information generation unit 160 to correct the image of the measurement target W. This corrected image of the measurement target W is then used during the image measurement process.

[0030] According to the vision measuring device 100 of the present invention, since the reference pattern is built into the device, it is not necessary to place the reference pattern on the stage when acquiring distortion information. Therefore, when acquiring distortion information during measurement, there is no need to replace the reference pattern on the stage with the measurement target. Consequently, the reference pattern can be automatically captured and distortion information generated at any desired timing (for example, immediately before or during image measurement). This reduces the effort required to acquire distortion information and allows for flexible distortion correction in response to environmental changes.

[0031] Furthermore, since images of the reference pattern and the measurement target are acquired separately, it is possible to perform image measurement with the same quality as that of conventional methods.

[0032] In addition, since a beam splitter is used to combine the light path from the reference pattern with the light path from the stage to the image capture unit, it is possible to retrofit the system to existing equipment.

[0033] [Second embodiment]

[0034] Figure 2 1 is a functional block diagram of a vision measuring device 101 according to a second embodiment. The vision measuring device 101 includes a stage 110, a reference pattern display unit 121, a first light source 131, a second light source 132, an image capturing unit 141, a distortion information generating unit 161, a correction unit 170, and a control unit 181.

[0035] A reference pattern is formed on the mounting surface of the stage 110 using a color filter mask that selectively transmits light of a predetermined wavelength range. The color filter mask serves as the reference pattern display unit 121. The reference pattern using the color filter mask can be formed by directly depositing it on the mounting surface of the stage 110, or by depositing it on the surface of a substrate such as glass and then placing the substrate on the mounting surface of the stage 110.

[0036] In this manner, the stage 110 and the reference pattern display unit 121 are configured as a single unit, and the measurement target W is placed on the reference pattern.

[0037] The first light source 131 is a light emitting member that emits light of a wavelength that is not transmitted through the color filter mask.

[0038] The second light source 132 is a light emitting member that emits light of a wavelength transmitted through the color filter mask.

[0039] The first light source 131 and the second light source 132 irradiate light on the subject at a brightness and position sufficient for image measurement and distortion correction when the image capturing unit 141 captures an image of the subject.

[0040] Image capture unit 141 is directed toward stage 110 (reference pattern display unit 121) to capture an image of measurement target W and the reference pattern formed by the color filter mask. Because the color filter mask is wavelength-selective, the captured image differs depending on whether the image is captured with only first light source 131 or only second light source 132 emitting light. Specifically, when only first light source 131 emits light, the emitted light does not pass through the color filter mask, resulting in an image that includes both the reference pattern formed by the color filter mask and measurement target W. If the image is captured with only second light source 132 emitting light, the emitted light passes through the color filter mask, resulting in an image that includes measurement target W but not the reference pattern.

[0041] Distortion information generation unit 161 generates distortion information based on an image containing the measurement target W and a reference pattern, an image containing the measurement target W but lacking the reference pattern (both captured by image capture unit 141), and pre-prepared design information for the reference pattern. Specifically, an image containing only the reference pattern is first generated by subtracting the image containing the measurement target W but lacking the reference pattern from the image containing the measurement target W along with the reference pattern. The dimensions of the reference pattern read from the reference pattern image thus obtained are then compared with the design dimensions and dimensional tolerances, and distortion information is generated based on the difference between the two.

[0042] The correction unit 170 corrects the image captured by the image capture unit 141 , which contains the measurement target W but lacks the reference pattern, by using the distortion information generated by the distortion information generation unit 160 , and outputs an image for image measurement.

[0043] The control unit 181 performs control based on information input by the operator or based on a program that describes the processing flow and the functions of each functional unit. The control unit 181 can be implemented by a personal computer that includes, for example, a CPU that executes the program to implement the described functions, various storage components that temporarily or permanently store programs and data, various input components such as a keyboard and a mouse, various display components, and various communication components such as wired or wireless communication components.

[0044] Under the control of the control unit 181 , the correction process in the second embodiment is performed as follows, for example.

[0045] When the operator places the measurement target W on stage 110 and issues a command to control unit 181, control unit 181 performs correction processing by controlling each functional unit according to the process flow described in the program. Specifically, first, by emitting light only from first light source 131, image capture unit 141 captures an image of the measurement target W along with the reference pattern. Furthermore, by emitting light only from second light source 132, image capture unit 141 captures an image containing the measurement target W but lacking the reference pattern. Each captured image can be stored in a suitable storage device. Next, distortion information generation unit 161 generates an image of the reference pattern based on the image containing the measurement target W and the reference pattern and the image containing the measurement target W but lacking the reference pattern. Distortion information is generated based on this reference pattern image and pre-prepared design information for the reference pattern. Correction unit 170 then uses the distortion information generated by distortion information generation unit 161 to correct the image containing the measurement target W but lacking the reference pattern. This corrected image is then used during image measurement.

[0046] According to the vision measuring device 101 of the present invention, since the reference pattern is built into the device, it is not necessary to place the reference pattern on the stage when acquiring distortion information. Therefore, when acquiring distortion information during measurement, there is no need to replace the reference pattern on the stage with the measurement target. Consequently, the reference pattern can be automatically captured and distortion information generated at any desired timing (for example, immediately before or during image measurement). This reduces the effort required to acquire distortion information and allows for flexible distortion correction in response to environmental changes.

[0047] Furthermore, since images of the reference pattern and the measurement target are acquired separately, it is possible to perform image measurement with the same quality as that of conventional methods.

[0048] Furthermore, unlike the first embodiment, since the stage 110 and the reference pattern display unit 121 are integrally configured, the optical path to the image capture unit 141 is common to both the measurement target W and the reference pattern. Therefore, compared to the vision measuring apparatus 100 of the first embodiment, it is easier to ensure that the distortion in the image of the measurement target W matches the distortion in the image of the reference pattern.

[0049] [Third embodiment]

[0050] Figure 3 1 is a functional block diagram of a vision measuring device 102 according to the third embodiment. The vision measuring device 102 includes a stage 110, a reference pattern display unit 122, a light source 130, an image capturing unit 142, a distortion information generating unit 162, a correction unit 172, and a control unit 182.

[0051] On the mounting surface of the stage 110, a reference pattern is formed, which serves as the reference pattern display unit 122. The reference pattern may be formed by directly drawing on the mounting surface of the stage 110, or may be formed by drawing on the surface of a substrate such as glass and then placing the substrate on the mounting surface of the stage 110. The term "drawing" herein refers to simply drawing a reference pattern on a surface, as well as engraving or film deposition.

[0052] In this manner, the stage 110 and the reference pattern display unit 122 are configured as a single unit, and the measurement target W is placed on the reference pattern.

[0053] The image capturing unit 142 is directed toward the stage 110 (reference pattern display unit 122 ) so as to capture images of the measurement target W and the drawn reference pattern.

[0054] The distortion information generating unit 162 generates distortion information based on the image containing the measurement target W and the reference pattern captured by the image capturing unit 142 and the design information of the reference pattern prepared in advance. Specifically, the dimensions of the reference pattern read from the image containing the measurement target W and the reference pattern are compared with the design dimensions and the dimensional tolerance, and distortion information is generated based on the difference therebetween.

[0055] The correction unit 172 corrects the image containing the measurement target W and the reference pattern using the distortion information generated by the distortion information generation unit 162 .

[0056] The control unit 182 performs control based on information input by the operator or based on a program that describes the processing flow and the functions of each functional unit. The control unit 182 can be implemented by a personal computer that includes, for example, a CPU that executes the program to implement the described functions, various storage components that temporarily or permanently store programs and data, various input components such as a keyboard and a mouse, various display components, and various communication components such as wired or wireless communication components.

[0057] Under the control of the control unit 182 , the correction process in the third embodiment is performed as follows, for example.

[0058] When the operator places the measurement target W on stage 110 and issues a command to control unit 182, control unit 182 performs correction processing by controlling each functional unit according to the processing flow described in the program. Specifically, first, light source 130 emits light, causing image capture unit 142 to capture an image of the reference pattern and measurement target W. The captured image can be stored in a suitable storage device. Next, distortion information generation unit 162 generates distortion information based on the image containing the measurement target W and the reference pattern, as well as pre-prepared design information for the reference pattern. Correction unit 172 then uses the distortion information generated by distortion information generation unit 162 to correct the image containing the measurement target W and the reference pattern. This corrected image is then used during image measurement.

[0059] According to the image measuring device 102 of the present invention, since the reference pattern is built into the device, it is not necessary to place the reference pattern on the stage when acquiring distortion information. Therefore, when acquiring distortion information during measurement, there is no need to replace the reference pattern on the stage with the measurement target. Consequently, the reference pattern can be automatically captured and distortion information generated at any desired timing (for example, immediately before or during image measurement). This reduces the effort required to acquire distortion information and allows for flexible distortion correction in response to environmental changes.

[0060] Unlike the first and second embodiments, the image used to generate the distortion information and the image to which the correction is finally applied include an image of the reference pattern, but since the image can be captured in a single shot, image measurement can be performed in the same amount of time and with the same image data size as conventional methods.

[0061] Furthermore, by simply drawing a reference pattern on the stage 110 , the vision measuring apparatus of the third embodiment can be realized at low cost.

[0062] [Fourth embodiment]

[0063] Figure 41 is a functional block diagram of a vision measuring device 103 according to a fourth embodiment. The vision measuring device 103 includes a stage 110, a reference pattern display unit 123, a light source 130, an image capturing unit 143, a reference pattern extracting unit 193, a distortion information generating unit 163, a correction unit 172, and a control unit 183.

[0064] On the mounting surface of the stage 110, a reference pattern is formed using a half-tone mask, which serves as the reference pattern display unit 123. The reference pattern using the half-tone mask may be formed by directly depositing it on the mounting surface of the stage 110, or may be formed by depositing it on the surface of a substrate such as glass and then placing the substrate on the mounting surface of the stage 110.

[0065] In this manner, the stage 110 and the reference pattern display unit 123 are configured as a single unit, and the measurement target W is placed on the reference pattern.

[0066] The image capturing unit 143 is directed toward the stage 110 (reference pattern display unit 123 ) so as to capture images of the measurement target W and the reference pattern formed by the half-tone mask.

[0067] The reference pattern extraction unit 193 extracts an image of a reference pattern from an image containing a reference pattern formed using a halftone mask and the measurement target W, which is captured by the image capture unit, based on, for example, a brightness value corresponding to the halftone mask.

[0068] Next, distortion information generation unit 163 generates distortion information based on the reference pattern image extracted by the reference pattern extraction unit and pre-prepared design information for the reference pattern. Specifically, the reference pattern dimensions read from the reference pattern image are compared with the design dimensions and dimensional tolerances, and distortion information is generated based on the difference between the two.

[0069] The correction unit 172 corrects the image containing the measurement target W and the reference pattern formed using the half-tone mask using the distortion information generated by the distortion information generation unit 163 .

[0070] The control unit 183 performs control based on information input by the operator or based on a program that describes the processing flow and the functions of each functional unit. The control unit 183 can be implemented by a personal computer that includes, for example, a CPU that executes the program to implement the described functions, various storage components that temporarily or permanently store programs and data, various input components such as a keyboard and a mouse, various display components, and various communication components such as wired or wireless communication components.

[0071] Under the control of the control unit 183 , the correction process in the fourth embodiment is performed as follows, for example.

[0072] When the operator places the measurement target W on stage 110 and issues a command to control unit 183, control unit 183 performs correction processing by controlling each functional unit according to the processing flow described in the program. Specifically, first, light source 130 emits light, causing image capture unit 143 to capture an image of the reference pattern formed using a halftone mask and the measurement target W. The captured image can be stored in a suitable storage device. Next, reference pattern extraction unit 193 extracts an image of the reference pattern from the image containing the reference pattern formed using a halftone mask and the measurement target W. Distortion information generation unit 163 then generates distortion information based on the image of the reference pattern extracted by reference pattern extraction unit 193 and pre-prepared design information for the reference pattern. Correction unit 172 then uses the distortion information generated by distortion information generation unit 163 to correct the image containing the measurement target W and the reference pattern formed using the halftone mask. This corrected image is then used during image measurement.

[0073] According to the image measuring device 103 of the present invention, since the reference pattern is built into the device, it is not necessary to place the reference pattern on the stage when acquiring distortion information. Therefore, when acquiring distortion information during measurement, there is no need to replace the reference pattern on the stage with the measurement target. Consequently, the reference pattern can be automatically captured and distortion information generated at any desired timing (for example, immediately before or during image measurement). This reduces the effort required to acquire distortion information and allows for flexible distortion correction in response to environmental changes.

[0074] Unlike the first and second embodiments, the image to which correction is finally applied includes an image of the reference pattern, but since the image can be captured in a single shot, image measurement can be performed in the same amount of time and with the same image data size as conventional methods.

[0075] In addition, unlike the third embodiment, the image measuring apparatus of the fourth embodiment can improve the accuracy of distortion correction because it extracts an image of a reference pattern from a captured image and then generates distortion information based on the extracted reference pattern.

[0076] The present invention is not limited to the above-described embodiments. The above-described embodiments are merely examples, and any configuration that is substantially the same as the technical concept described in the claims of the present invention and produces similar effects is included within the technical scope of the present invention, even if components are added, deleted, or modified. In other words, appropriate changes can be made within the scope of the technical concept expressed in the present invention, and forms with such changes and improvements are also included within the technical scope of the present invention.

[0077] Regarding the embodiments including the above examples, the following appendix is ​​further disclosed.

[0078] (Appendix 1) An image measuring device includes: a stage on which a measurement target is placed;

[0079] a reference pattern display unit on which a reference pattern is displayed;

[0080] an image capturing unit that captures an image of a subject;

[0081] a distortion information generating unit that generates distortion information based on the image of the reference pattern captured by the image capturing unit and design information of the reference pattern; and

[0082] A correction unit that corrects the image of the measurement target captured by the image capture unit using the distortion information.

[0083] (Appendix 2) The vision measuring apparatus according to Appendix 1, further including: an object switching unit that switches an object to be captured by the image capturing unit between the measurement target and the reference pattern.

[0084] (Appendix 3) The vision measuring device according to Appendix 2, wherein the object switching unit includes:

[0085] a beam splitter that transmits incident light from the measurement target and incident light from the reference pattern display unit toward the image capturing unit; and

[0086] shutters, which are respectively provided between the measurement target and the beam splitter, and between the reference pattern display unit and the beam splitter, and

[0087] By opening and closing the corresponding shutter, the subject to be captured by the image capturing unit is switched.

[0088] (Appendix 4) The image measuring apparatus according to Appendix 1, wherein the reference pattern is formed by using a color filter mask on a mounting surface on which the measurement target is placed, the stage is configured integrally with the reference pattern display unit, and

[0089] The image measuring apparatus includes a first light source emitting light of a wavelength that is not transmitted through the color filter mask, and a second light source emitting light of a wavelength that is transmitted through the color filter mask, and

[0090] wherein the distortion information generating unit generates the distortion information based on an image containing the measurement target and the reference pattern captured by the image capturing unit when only the first light source emits light, an image containing the measurement target but lacking the reference pattern captured by the image capturing unit when only the second light source emits light, and design information of the reference pattern, and

[0091] The correction unit corrects an image containing the measurement target but lacking the reference pattern using the distortion information.

[0092] (Appendix 5) The vision measuring apparatus according to Appendix 1, wherein the stage is configured integrally with the reference pattern display unit by forming the reference pattern on a mounting surface on which the measurement target is placed,

[0093] the distortion information generating unit generates distortion information based on an image containing the measurement target and the reference pattern captured by the image capturing unit, and design information of the reference pattern, and

[0094] The correction unit corrects an image including the measurement target and the reference pattern using the distortion information.

[0095] (Appendix 6) The image measuring apparatus according to Appendix 1, wherein the reference pattern is formed by using a half-tone mask on a mounting surface on which the measurement target is placed, and the stage is configured integrally with the reference pattern display unit, and

[0096] The image measuring apparatus further includes a reference pattern extraction unit that extracts an image of the reference pattern from an image captured by the image capture unit and containing the measurement target and the reference pattern formed using the halftone mask, and

[0097] wherein the distortion information generating unit generates the distortion information based on the image of the reference pattern extracted by the reference pattern extracting unit and the design information of the reference pattern, and

[0098] The correction unit corrects an image including the measurement target and the reference pattern formed using the half-tone mask using the distortion information.

[0099] (Appendix 7) A non-transitory recording medium recording a program for causing a computer to function as the image measuring apparatus according to any one of Appendices 1 to 6.

Claims

1. An image measurement device, comprising: a stage on which a measurement target is placed; a reference pattern display unit on which a reference pattern is displayed; an image capturing unit that captures an image of a subject; a distortion information generating unit that generates distortion information based on the image of the reference pattern captured by the image capturing unit and design information of the reference pattern; as well as A correction unit that corrects the image of the measurement target captured by the image capture unit using the distortion information.

2. The image measuring device according to claim 1, further comprising: an object switching unit that switches an object to be captured by the image capturing unit between the measurement target and the reference pattern.

3. The image measuring device according to claim 2, wherein: The object switching unit includes: a beam splitter that transmits incident light from the measurement target and incident light from the reference pattern display unit toward the image capturing unit; and shutters, which are respectively provided between the measurement target and the beam splitter, and between the reference pattern display unit and the beam splitter, and By opening and closing the corresponding shutter, the subject to be captured by the image capturing unit is switched.

4. The image measuring device according to claim 1, wherein forming the reference pattern by using a color filter mask on a mounting surface on which the measurement target is placed, the stage being configured integrally with the reference pattern display unit, and The image measuring apparatus includes a first light source that emits light of a wavelength that is not transmitted through the color filter mask, and a second light source that emits light of a wavelength that is transmitted through the color filter mask, and wherein the distortion information generating unit generates the distortion information based on an image containing the measurement target and the reference pattern captured by the image capturing unit when only the first light source emits light, an image containing the measurement target but lacking the reference pattern captured by the image capturing unit when only the second light source emits light, and design information of the reference pattern, and The correction unit corrects an image containing the measurement target but lacking the reference pattern using the distortion information.

5. The image measuring device according to claim 1, wherein The stage is configured integrally with the reference pattern display unit by forming the reference pattern on a mounting surface on which the measurement target is placed, the distortion information generating unit generates distortion information based on an image containing the measurement target and the reference pattern captured by the image capturing unit, and design information of the reference pattern, and The correction unit corrects an image including the measurement target and the reference pattern using the distortion information.

6. The image measuring device according to claim 1, wherein The stage is configured integrally with the reference pattern display unit by forming the reference pattern using a half-tone mask on a mounting surface on which the measurement target is placed, The image measuring apparatus further includes a reference pattern extraction unit that extracts an image of the reference pattern from an image captured by the image capture unit and containing the measurement target and the reference pattern formed using the halftone mask, and wherein the distortion information generating unit generates the distortion information based on the image of the reference pattern extracted by the reference pattern extracting unit and the design information of the reference pattern, and The correction unit corrects an image including the measurement target and the reference pattern formed using the half-tone mask using the distortion information. 7 . A non-transitory recording medium recording a program for causing a computer to function as the vision measuring apparatus according to claim 1 .

Images