Image processing device, image processing system, program, and image processing method

Abstract

The present invention provides an image processing device which is capable of displaying, in a region missing due to blur correction, an image corresponding to this region.　An image processing device 1 comprises: a blur correction unit 20 that generates a blur-corrected image in which the position of the field of view of an input image differing in input timing from an arbitrary reference image among time-series input images is aligned with respect to the reference image; a differential image creation unit 21 that creates a differential image by setting an arbitrary input image as a reference image and subtracting the reference image from a blur-corrected image of an input image differing in time from the reference image; and an output image creation unit 22 that creates an output image by adding, to a missing portion of the differential image in which the position of the field of view has been returned, said portion in the original input image before the blur-correction.

Description

Image processing apparatus, image processing system, program, and image processing method ,

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[0001] The present disclosure relates to an image processing apparatus, an image processing system, a program, and a fluid image processing method for detecting leakage of a fluid such as gas from time-series images.

[0002] When a gas leak occurs and an infrared camera takes a picture, a slight temperature change occurs and the picture is taken. As a technique for detecting gas using this principle, gas detection using an infrared camera is known. During the shooting of a monitoring target by an infrared camera, blurring may occur due to the shaking of the infrared camera. As a result, the infrared image taken by the infrared camera contains noise due to camera blurring, so the detection accuracy of gas decreases.

[0003] Therefore, a technique has been proposed for correcting each of a plurality of images arranged in time series based on a value indicating the blurring of each (see, for example, Patent Document 1).

[0004] International Publication No. WO2017 / 179510

[0005] Conventionally, an infrared camera for taking pictures of gas is assumed to be used while fixed with a tripod or the like. On the other hand, in order to improve the efficiency of gas inspection work, there is a demand from users to take pictures of an infrared camera by hand.

[0006] By taking pictures with the infrared camera fixed, the image position of the gas area does not shift between time-series images such as videos. On the other hand, when taking pictures with an infrared camera by hand, the shooting field of view may move by an operation of horizontally moving the camera, so-called panning.

[0007] However, when each of a plurality of images is corrected by the method of Patent Document 1, in the image generated from the time-series images, areas that are missing appear because the fields of view are different. If there are missing areas in the image, it becomes difficult to grasp the field of view of where the picture is being taken, especially when panning. Therefore, it becomes difficult to confirm visually the location where a gas leak has occurred from the image.

[0008] This disclosure aims to solve these problems by providing an image processing device that can display an image corresponding to a region that is missing due to blur correction. Furthermore, this disclosure aims to provide an image processing system equipped with an image processing device, a program executed by the image processing device, and an image processing method.

[0009] To solve the above-mentioned problems, this disclosure provides an image processing apparatus comprising: a blur correction unit that aligns the image positions of input images at least two different time points to generate a blur-corrected image; a minute change visualization image creation unit that creates a minute change visualization image in which minute changes between input images at at least two different time points are visualized using the blur-corrected images at at least two different time points; and an output image creation unit that creates an output image in which an additional image is displayed in an area outside the common field of view of the minute change visualization image created using the blur-corrected images at at least two different time points and the input image before blur correction.

[0010] Furthermore, this disclosure provides an image processing system comprising: an image acquisition unit that photographs a subject including a subject to be monitored and generates an input image; and an image processing device, the image processing device comprising: a blur correction unit that aligns the image positions of input images at least two different time points to generate a blur-corrected image; a minute change visualization image creation unit that creates a minute change visualization image in which minute changes between input images at at least two different time points are visualized using blur-corrected images at at least two different time points; and an output image creation unit that creates an output image in which an additional image is displayed in an area outside the common field of view of the minute change visualization image created using blur-corrected images at at least two different time points and the input image before blur correction.

[0011] Furthermore, this disclosure is a program executed on a computer of an image processing device, which causes the computer to perform the following steps: generate a blur-corrected image by aligning the image positions of input images at least two different time points; create a minute change visualization image in which minute changes between input images at at least two different time points are visualized, using the blur-corrected images at at least two different time points; and create an output image in which an additional image is displayed in an area outside the common field of view of the minute change visualization image created using the blur-corrected images at at least two different time points and the input image before blur correction.

[0012] Furthermore, this disclosure is an image processing method that performs the steps of: generating a blur-corrected image by aligning the image positions of input images at least two different time points; creating a minute change visualization image in which minute changes between input images at at least two different time points are visualized using the blur-corrected images at at least two different time points; and creating an output image in which an additional image is displayed in an area outside the common field of view between the minute change visualization image created using the blur-corrected images at at least two different time points and the input image before blur correction.

[0013] According to this disclosure, image correction allows for the display of the corresponding image in the area where the image was lost, making it easy to visually identify what was being photographed. Therefore, it becomes easier to visually confirm the location of a gas leak by examining the image.

[0014] This is a functional block diagram showing an example of an image processing apparatus and image processing system in this embodiment. This is a flowchart showing an example of an image processing method in this embodiment. This is an explanatory diagram showing an example of a time-series input image. This is an explanatory diagram showing an example of an image after blur correction. This is an explanatory diagram showing an example of the process for creating a difference image. This is an explanatory diagram showing an example of the process for creating a difference image without blur correction. This is an explanatory diagram showing an example of the process for creating a difference image and restoring the image position. This is an explanatory diagram showing an example of the process for creating an output image. This is an explanatory diagram showing an example of an image with a large missing area. This is an explanatory diagram showing an example of an image after time-frequency processing.

[0015] Hereinafter, embodiments of the image processing apparatus in this disclosure will be described with reference to the drawings. Furthermore, embodiments of the image processing system, the program executed on the computer of the image processing apparatus, and the image processing method in this disclosure will be described.

[0016] <Example of the configuration of the image processing apparatus, image processing system, and program of this embodiment> Figure 1 is a functional block diagram showing an example of the image processing apparatus and image processing system of this embodiment. The image processing apparatus 1 comprises an image processing unit 2 and a storage unit 3. The image processing system 100 comprises an image processing apparatus 1, an image acquisition unit 4, and an output unit 5.

[0017] The image acquisition unit 4 photographs subjects including the gas leak monitoring target and generates an input image. The gas leak monitoring target is, for example, a point where gas transport pipes are connected to each other.

[0018] In this example, the image acquisition unit 4 includes an infrared camera 4a and a visible camera 4b. The infrared camera 4a captures infrared images taken in a time series, such as a video of infrared images, as input images. The infrared images can be any multiple infrared images taken in a time series, and are not limited to a video. The visible camera 4b captures visible images taken in a time series, such as a video of visible images, as input images. The visible images can be any multiple visible images taken in a time series, and are not limited to a video.

[0019] The infrared camera 4a comprises an optical system 40a, a filter 41a, an image sensor 42a, and a signal processing unit 43a. The optical system 40a is a lens that forms an infrared image of the subject on the image sensor 42a.

[0020] The filter 41a is placed between the optical system 40a and the image sensor 42a, and allows only infrared light of a specific wavelength to pass through the optical system 40a. The wavelength band of infrared light that passes through the filter 41a depends on the type of gas being detected.

[0021] The image sensor 42a is a two-dimensional image sensor that receives infrared light that has passed through the filter 41a. The signal processing unit 43a converts the analog signal output from the image sensor 42a into a digital signal and performs known image processing to generate an infrared image.

[0022] The visible camera 4b comprises an optical system 40b, a filter 41b, an image sensor 42b, and a signal processing unit 43b. The optical system 40b is a lens that forms a visible image of the subject on the image sensor 42b.

[0023] The filter 41b is placed between the optical system 40b and the image sensor 42b, and allows visible light to pass through the optical system 40b.

[0024] The image sensor 42b is a two-dimensional image sensor that receives visible light that has passed through the filter 41b. The signal processing unit 43b converts the analog signal output from the image sensor 42b into a digital signal and performs known image processing to generate a visible image.

[0025] The image acquisition unit 4 may consist only of an infrared camera 4a or only of a visible-lens camera 4b. Alternatively, the image acquisition unit 4 may be integrated into the image processing device 1. Furthermore, the image acquisition unit 4 may consist of a camera independent of the image processing device 1, connected to the image processing device 1.

[0026] The image processing device 1 is a personal computer, smartphone, tablet terminal, etc. Alternatively, the image processing device 1 may be installed in a camera equipped with an image acquisition unit 4.

[0027] The image processing unit 2 is an example of a control unit and consists of a CPU (Central Processing Unit) and the like. The image processing unit 2 includes a blur correction unit 20, a difference image creation unit 21, and an output image creation unit 22.

[0028] The image correction unit 20 aligns the image positions of input images at at least two different time points. Specifically, the image correction unit 20 aligns the field of view positions of input images with different input timings relative to an arbitrary reference image in the time-series input images. This correction, which aligns the image positions of input images at at least two different time points, is called image correction. The input image after image correction is referred to as the image after image correction.

[0029] When the image stabilization unit 20 performs image stabilization on an infrared image as the input image, it aligns the field of view positions of time-series infrared images input at at least two different times. The image stabilization performed on the infrared image is referred to as the image stabilization infrared image. If the infrared image is a video, the image stabilization unit 20 aligns the field of view positions of the image frame by frame; if it is a series of still images, it aligns the field of view positions of the image frame by frame. If the infrared image is a series of still images, the image stabilization unit 20 aligns the field of view positions of the image frame by frame. The image stabilization performed on the visible image is referred to as the image stabilization visible image. For example, the correction to align the field of view positions of the image is performed using the method described in international publication number WO2017 / 179510, filed by the same applicant as the present invention.

[0030] The difference image creation unit 21 creates an image in which minute changes between input images at at least two different time points are visualized, using blur-corrected images at at least two different time points. The difference image creation unit 21 is an example of a minute change visualization image creation unit. Furthermore, an image in which minute changes are visualized is referred to as a minute change visualization image.

[0031] Specifically, the difference image creation unit 21 performs time difference processing and creates a difference image from the reference image using blur-corrected images from at least two different time points. For example, the difference image creation unit 21 uses an arbitrary input image as the reference image and creates a difference image by subtracting the reference image from the blur-corrected image of an input image taken at a different time point than the reference image.

[0032] The difference image creation unit 21, when the input image is an infrared image, subtracts the reference image from the blur-corrected infrared image to create an infrared difference image. Also, when the input image is a visible image, the difference image creation unit 21 subtracts the reference image from the blur-corrected visible image to create a visible difference image. The difference image is an example of a micro-change visualization image where minute changes are visualized.

[0033] Furthermore, the difference image creation unit 21 returns the position of the difference image to the image position of the original image before blur correction. If there is a difference in image position between the reference image and the input image which has a different input timing than the reference image, the image after blur correction will have missing parts where the image is missing due to the blur correction. For this reason, the difference image whose image position has been returned will also have missing parts where the image is missing due to the blur correction.

[0034] The output image creation unit 22 creates an output image in which an additional image is displayed in the area outside the common field of view of the minute change visualization image created using the image after blur correction and the input image before blur correction.

[0035] Specifically, the output image creation unit 22 creates an output image by adding the corresponding portion of the original input image before blur correction to the missing portion of the difference image in which the field of view position has been restored. If the input image is an infrared image, the output image creation unit 22 adds the corresponding portion of the original infrared image before blur correction to the missing portion of the infrared difference image in which the field of view position has been restored. If the input image is a visible image, the output image creation unit 22 adds the corresponding portion of the original visible image before blur correction to the missing portion of the visible difference image in which the field of view position has been restored.

[0036] The memory unit 3 includes RAM (Random Access Memory), ROM (Read Only Memory), HDD (Hard Disk Drive), SSD (Solid State Drive), etc. The memory unit 3 stores input images, difference images such as images visualizing minute changes, output images, etc. The memory unit 3 also stores programs.

[0037] The output unit 5 is composed of a display or the like. For example, the output unit 5 is a liquid crystal display. Alternatively, the output unit 5 may be an organic light-emitting diode display (OLED display), a plasma display, or the like instead of a liquid crystal display. The output unit 5 may be provided in the image processing device 1. The output unit 5 may also be the display of a mobile terminal device connected to the image processing device 1, or the display of a computer connected to the image processing device 1.

[0038] <Example of program function> The image processing device 1 implements the functions of the blur correction unit 20, the difference image creation unit 21, and the output image creation unit 22 described above by executing a program in the image processing unit 2.

[0039] The program implements the blur correction unit 20 by causing the image processing unit 2 to perform blur correction processing to align the image positions of input images at least two different time points.

[0040] Furthermore, the program instructs the image processing unit 2 to perform a process to create a micro-change visualization image using blur-corrected images from at least two different time points. This realizes the micro-change visualization image creation unit. In this example, the program instructs the image processing unit 2 to perform a process to create a difference image, thereby realizing the difference image creation unit 21 as the micro-change visualization image creation unit.

[0041] Furthermore, the program realizes the output image creation unit 22 by having the image processing unit 2 execute a process to create an output image by adding the original image to the missing parts of the difference image.

[0042] Furthermore, the program executes the steps of image stabilization, difference image creation, and output image creation in a predetermined order.

[0043] The program is stored in the storage unit 3. Furthermore, in configurations where the image processing device 1 can connect to an external storage medium such as an HDD or SSD, the program may be stored and provided on the external storage medium. Additionally, the program may be stored on a server connected to the image processing device 1 via a wired or wireless network, and the image processing device 1 may receive the program via the network.

[0044] Also, by updating the program, each function of blur correction processing, difference image creation processing, and output image creation processing may be added.

[0045] In the image processing unit 2, part or all of the blur correction processing, difference image creation processing, and output image creation processing may be realized by processing by the CPU. Also, in the image processing unit 2, part or all of the above functions may be realized by processing by a DSP (Digital Signal Processor) instead of or together with the CPU. Further, part or all of the above functions may be realized by processing by a dedicated hardware circuit instead of or together with processing by software.

[0046] <Operation Example of Image Processing Method> FIG. 2 is a flowchart showing an example of the image processing method in the present embodiment. Next, as an image processing method, an example of the operation of the image processing apparatus 1 executed by a program will be described.

[0047] The blur correction unit 20 aligns the image positions of input images at at least two different times in the blur correction processing of step SA1.

[0048] FIG. 3 is an explanatory diagram showing an example of time-series input images, and FIG. 4 is an explanatory diagram showing an example of an image after blur correction. The following operation example shows the case where the input image is an infrared image. FIG. 3 shows an infrared image MD0 of the first frame, an infrared image MD1 0.1 seconds after the first frame, and an infrared image MD2 0.2 seconds after the first frame.

[0049] FIG. 4 shows a case where, for example, the infrared image MD0 of the first frame is used as a reference image for blur correction. In this case, it shows the infrared image MaD2 after blur correction of the infrared image MD1 and the infrared image MaD2 after blur correction of the infrared image MD2.

[0050] The blur correction unit 20 generates a blur-corrected infrared image MaD1 in which the image position of the infrared image MD1 is aligned with the reference image, using the infrared image MD0 as the reference image for blur correction. Also, the blur correction unit 20 generates a blur-corrected infrared image MaD2 in which the image position of the infrared image MD2 is aligned with the reference image.

[0051] If the camera constituting the image acquisition unit 4 is moved horizontally during shooting, the shooting field of view shifts, causing the image positions to differ between time-series images. For example, if the image positions of infrared image MD0 and infrared image MD1 are different, a missing area Ma1 will appear in the image-corrected infrared image MaD1, depending on the amount of blur correction. Similarly, if the image positions of infrared image MD0 and infrared image MD2 are different, a missing area Ma2 will appear in the image-corrected infrared image MaD2, depending on the amount of blur correction.

[0052] The difference image creation unit 21 creates a difference image from at least two different time-corrected images in the difference image creation process of step SA2. The difference image creation unit 21 also returns the position of the difference image to the position of the original image before blur correction.

[0053] Figure 5 is an explanatory diagram showing an example of the process for creating a difference image. The difference image creation unit 21, for example, uses the infrared image MD0 as a reference image and subtracts the reference image from the blur-corrected infrared image MaD2 to create an infrared difference image McD2.

[0054] Figure 6 is an explanatory diagram showing an example of the process for creating a difference image without blur correction, as a comparative example. For example, infrared image MD0 is used as the reference image, and the reference image is subtracted from infrared image MD2 to create infrared difference image McD2b. In this way, infrared difference image McD2b, which is obtained by taking the time difference without aligning the field of view positions, becomes visible due to blur noise components, making it difficult to identify gas even if it is present. In contrast, infrared difference image McD2b created using blur-corrected infrared image McD2 suppresses blur noise components, making it easier to identify gas.

[0055] Figure 7 is an explanatory diagram illustrating an example of the process of creating a difference image and restoring the image position. Figure 7 shows an example in which a blur-corrected infrared image MaD2 is created from the infrared image MD2, and an infrared difference image McD2 is created from the blur-corrected infrared image MaD2. The difference image creation unit 21 creates an infrared difference image MdD2 by restoring the position of the infrared difference image McD2 to the image position of the original image, infrared image MD2, before blur correction.

[0056] As shown in Figures 5 and 7, the image-corrected infrared image MaD2 has missing areas Ma2 depending on the amount of image correction. Also, since the infrared difference image McD2 is created using the image-corrected infrared image MaD2, missing areas Mc2 with no image are created depending on the amount of image correction. As a result, the infrared difference image MdD2, with its image position restored, has missing areas Md2 with no image in the region outside the common field of view with the infrared image MD2 before image correction.

[0057] In the output image creation process of step SA3, the output image creation unit 22 creates an output image by adding the corresponding portion of the input image before blur correction to the missing portion of the difference image in which the field of view position has been restored.

[0058] Figure 8 is an explanatory diagram showing an example of the output image creation process. As described above, the difference image, in which the image position has been restored, has missing areas where there is no image in the region outside the common field of view with the input image before blur correction. The input image before blur correction includes the area corresponding to this missing area.

[0059] Therefore, the output image creation unit 22 adds an additional image Me2 to the region outside the common field of view of the infrared difference image MdD2 and the infrared image MD2 before image correction. The additional image Me2 is, for example, the region Me in the original input image, the infrared image MD2 before image correction, that is outside the common field of view of the infrared difference image MdD2. As a result, the output image creation unit 22 creates an output image MeD2 in which the additional image Me2 is displayed in the missing portion Md2 of the infrared difference image MdD2. In this way, by adding the additional image Me2 from the infrared image MD2 before image correction to the missing portion Md2 of the infrared difference image MdD2, the field of view of the output image MeD2 becomes easier to understand.

[0060] Figure 9 is an explanatory diagram showing an example of an image with a large defect. As shown in Figure 3, when the camera constituting the image acquisition unit 4 is held by hand to fix the field of view as much as possible, the defect Md2 is small, as shown in Figure 8.

[0061] In contrast, when shooting while panning, the area of ​​the missing portion Md2b becomes larger compared to the missing portion Md2 when the field of view is kept as fixed as possible, as shown in Figure 9. Even in such cases, by adding an additional image Me2b from the infrared image MD2 before image correction to the missing portion Md2b, the output image MeD2b becomes easier to understand in terms of the captured field of view.

[0062] Furthermore, if the area of ​​the image added to the missing portion Md2b is large, the added image Me2b may be more prominent than the infrared difference image MdD2b. In this case, it becomes difficult to determine what image mode is being used to display the image, such as whether the camera is trying to display an infrared difference image or an infrared image.

[0063] Therefore, to enhance the image in the original image mode, the additional image Me2c may be displayed as a dark image. For example, the brightness value of the additional image Me2c can be set to half of the range of 0 to 255 relative to the infrared difference image MdD2b, thereby making the additional image Me2c a dark image using only specific brightness values. In the output image MeD2c created in this way, the infrared difference image MdD2b is relatively enhanced compared to the additional image Me2c, resulting in an image that is easier to understand what is being displayed.

[0064] Figure 10 is an explanatory diagram showing an example of an image that has undergone time-frequency processing. In the above explanation, time-difference processing was used as an example of the process for visualizing gas. Alternatively, the method described in international publication number WO2017 / 073430 may be used to capture the changes in gas as it fluctuates due to wind using time-frequency processing, and a frequency image from which the gas has been extracted may be created.

[0065] In this case as well, since multiple time-series images are used, missing data occurs, similar to the case of time-difference processing. For example, when an infrared image is used as the input image, a missing portion Mf2b occurs in the infrared frequency image MfD2b, as shown in Figure 9. The missing portion Mf2b is an area outside the common field of view between the infrared frequency image MfD2b and the infrared image MD2 before blur correction, as shown in Figure 7, etc.

[0066] Therefore, the output image creation unit 22 adds an additional image Mg2b to the missing portion Mf2b of the infrared frequency image MfD2b. The additional image Mg2b is, for example, a region outside the common field of view with the infrared frequency image MfD2b in the original input image, which is the infrared image MD2 before blur correction. As a result, the output image creation unit 22 creates an output image MgD2b in which the additional image Mg2b is displayed over the missing portion Mf2b of the infrared frequency image MfD2b, as shown in Figure 9.

[0067] Furthermore, if the area of ​​the image added to the missing portion Mf2b is large, the added image Mg2b may still stand out more than the infrared frequency image MfD2b. For this reason, the added image Mh2c may be displayed as a dark image so that the image in the original image mode can be emphasized. For example, by setting the brightness value of the added image Mh2c to half of the range of 0 to 255 relative to the infrared frequency image MfD2b, the added image Mg2c can be made a dark image using only a specific brightness value. In the output image MgD2c created in this way, the infrared frequency image MfD2b is relatively emphasized compared to the added image Mg2c, resulting in an image where it is easier to see what is being displayed.

[0068] Furthermore, the additional images added to the missing areas are not limited to infrared images; they may also be thermal images that represent temperature from blue to red. Also, in cases where a visible camera is also used in addition to an infrared camera, such as with gas cameras or thermal cameras, the additional images added to the missing areas may also be visible images. In other words, the corresponding portion of a visible image captured simultaneously with the infrared image before image correction may be added to the missing areas of the infrared difference image or frequency image.

[0069] Furthermore, although an embodiment in which time-difference processing is performed using an infrared image as the input image has been described, a visible image may also be used as the input image. Steam and smoke can be detected from a visible image, and after converting the visible image to a luminance image, time-difference processing and time-frequency processing can be performed. Then, the corresponding portion of the visible image before blur correction can be added to the missing parts of the visible difference image and frequency image. Alternatively, the corresponding portion of an infrared image captured simultaneously with the visible image before blur correction may be added to the missing parts of the visible difference image and frequency image.

[0070] This disclosure can be used in image processing equipment, image processing systems, programs, and fluid image processing methods for detecting leaks of fluids such as gas from time-series images.

[0071] 1...Image processing device, 2...Image processing unit, 20...Shake correction unit, 21...Difference image creation unit, 22...Output image creation unit, 3...Storage unit, 4...Image acquisition unit, 4a...Infrared camera, 4b...Visible camera, 5...Output unit, 100...Image processing system

Claims

1. An image processing apparatus comprising: a blur correction unit that aligns the image positions of input images at least two different time points to generate a blur-corrected image; a minute change visualization image creation unit that creates a minute change visualization image in which minute changes between input images at at least two different time points are visualized, using the blur-corrected images at at least two different time points; and an output image creation unit that creates an output image in which an additional image is displayed in an area outside the common field of view of the minute change visualization image created using the blur-corrected images at at least two different time points and the input image before blur correction.

2. The image processing apparatus according to claim 1, wherein the input image is an infrared image.

3. The image processing apparatus according to claim 1, wherein the input image is a visible image.

4. The image processing apparatus according to claim 1, wherein the minute change visualization image is an image obtained by performing time difference processing using blur-corrected images from at least two different time points.

5. The image processing apparatus according to claim 1, wherein the minute change visualization image is an image obtained by performing time-frequency processing using blur-corrected images at at least two different time points.

6. The image processing apparatus according to claim 1, wherein the additional image is a part of the input image before blur correction.

7. The image processing apparatus according to claim 1, wherein the additional image is a part of an input image taken by another camera simultaneously with the input image before blur correction.

8. The image processing apparatus according to claim 1, wherein the additional image is an image using only specific brightness values.

9. An image processing system comprising: an image acquisition unit that photographs a subject including a subject to be monitored and generates an input image; and an image processing device, wherein the image processing device comprises: a blur correction unit that aligns the image positions of input images at least two different time points to generate a blur-corrected image; a minute change visualization image creation unit that creates a minute change visualization image in which minute changes between input images at at least two different time points are visualized using blur-corrected images at at least two different time points; and an output image creation unit that creates an output image in which an additional image is displayed in an area outside the common field of view of the minute change visualization image created using blur-corrected images at at least two different time points and the input image before blur correction.

10. A program executed on a computer of an image processing device, which causes the computer to perform the following steps: generate a blur-corrected image by aligning the image positions of input images at least two different time points; create a minute change visualization image, in which minute changes between input images at at least two different time points are visualized, using the blur-corrected images at at least two different time points; and create an output image in which an additional image is displayed in an area outside the common field of view of the minute change visualization image created using the blur-corrected images at at least two different time points and the input image before blur correction.

11. An image processing method comprising the steps of: generating a blur-corrected image by aligning the image positions of input images at least two different time points; creating a minute change visualization image, in which minute changes between input images at at least two different time points are visualized, using the blur-corrected images at at least two different time points; and creating an output image in which an additional image is displayed in the area outside the common field of view between the minute change visualization image created using the blur-corrected images at at least two different time points and the input image before blur correction.

Images