Information processing device, information processing method, and information processing program

Abstract

To provide an information processing device, an information processing method and an information processing program capable of estimating a size distribution of particles with high accuracy in estimating the size distribution of particles constituting a material from a material structure image by using Fourier transformation.SOLUTION: An information processing device 10 acquires a maximum particle size representing the size of the largest particle among particles reflected in a material structure image. The information processing device 10 determines the size of a padding region to be set in the material structure image. The information processing device 10 generates a padded material structure image by setting the padding region of the determined size in the material structure image. The information processing device 10 executes Fourier transformation to the generated padded material structure image, and calculates a size distribution of particles reflected in the material structure image on the basis of a Fourier transformation result being an execution result.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to an information processing device, an information processing method, and an information processing program. [Background technology]

[0002] Conventionally, a particle size measurement method is known that can easily and accurately determine the particle size of metal particles on a polycrystalline body using image processing (see, for example, Patent Document 1). In the method disclosed in Patent Document 1, the substance to be measured is photographed with an imaging device to obtain an electronic data image. Next, in the method disclosed in Patent Document 1, the obtained electronic image data is subjected to a Fourier transform to convert it into an image signal consisting of a plurality of different frequency components, and then an image signal of a specific frequency generated by the particles of the object to be measured is extracted by bandpass filter processing. Then, in the method disclosed in Patent Document 1, the obtained image signal of the specific frequency is subjected to flattening processing and contrast adjustment to extract the particles of the object to be measured. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2009-63565 A Summary of the Invention [Problem to be solved by the invention]

[0004] The technique disclosed in Patent Document 1 extracts particles of a measurement object that are captured in electronic image data by performing a Fourier transform on the electronic image data.

[0005] It should be noted that, when calculating the size distribution of particles in an image showing a material structure (hereinafter also simply referred to as a material structure image), it is possible to use a Fourier transform, which is an example of a known frequency analysis. However, when using the results of the Fourier transform on a material structure image to estimate the size distribution of particles shown in the material structure image, there is a problem in that the estimation accuracy may decrease depending on the relationship between the size of the particles shown in the material structure image and the size of the material structure image.

[0006] In consideration of the above, the present invention aims to provide an information processing device, an information processing method, and an information processing program capable of accurately estimating the particle size distribution of particles constituting a material from a material structure image using Fourier transform. [Means for solving the problem]

[0007] The information processing device according to the first embodiment is an information processing device including: an acquisition unit that acquires a material structure image showing a material structure; a particle size acquisition unit that acquires a maximum particle size representing the size of the largest particle among the particles appearing in the material structure image acquired by the acquisition unit; a determination unit that, when estimating the size distribution of particles present in the material structure image based on a padded image, which is an image obtained when a padding area is set for the material structure image, determines the size of the padding area to be set in the material structure image by determining the ratio between the maximum particle size and an image size representing the size of the padded image so that the fluctuation range of the estimation result of the maximum particle size when the size of the padding area is changed is equal to or less than a predetermined threshold; a setting unit that generates the padded material structure image by setting the padding area of ​​the size determined by the determination unit for the material structure image; and a calculation unit that performs a Fourier transform on the padded material structure image generated by the setting unit, and calculates the size distribution of particles appearing in the material structure image based on the Fourier transform result that is the execution result.

[0008] The information processing device acquires a material structure image showing a material structure. The information processing device acquires a maximum particle size representing the size of the largest particle among particles appearing in the acquired material structure image. When estimating a size distribution of particles present in the material structure image based on a padded image, which is an image when a padding region is set for the material structure image, the information processing device determines a size of a padding region to be set in the material structure image by determining a ratio between the maximum particle size and an image size representing the size of the padded image such that a fluctuation range of an estimation result of the maximum particle size when the size of the padding region is changed is equal to or smaller than a predetermined threshold. The information processing device generates a padded material structure image by setting a padding region of the determined size for the material structure image. The information processing device performs a Fourier transform on the generated padded material structure image, and calculates a size distribution of particles appearing in the material structure image based on the Fourier transform result that is the execution result. This makes it possible to accurately estimate the size distribution of particles when estimating the size distribution of particles constituting a material from the material structure image using a Fourier transform.

[0009] The determination unit of the information processing device according to the second aspect obtains data representing a relationship between the maximum particle size and the image size from a database according to the maximum particle size, and determines the size of the padding area according to the data representing the relationship. This makes it possible to accurately and easily estimate the particle size distribution based on the previously set relationship between the maximum particle size and the image size.

[0010] The determination unit of the information processing device according to the third aspect determines the size of the padding area by repeatedly calculating the ratio between the maximum particle size and the image size, thereby making it possible to accurately and easily estimate the particle size distribution based on the actual repeated calculation result of the ratio between the maximum particle size and the image size.

[0011] The determination unit of the information processing device according to the fourth aspect obtains data representing a relationship between the image size and a calculation time of the Fourier transform from a database according to the image size, and determines the size of the padding region according to the data representing the relationship. This makes it possible to accurately estimate the particle size distribution while reducing calculation costs when estimating the particle size distribution of a material from a material structure image using a Fourier transform.

[0012] An information processing method according to a fifth aspect is an information processing method in which a computer executes processes to acquire a material structure image showing a material structure, acquire a maximum particle size representing the size of the largest particle among particles appearing in the acquired material structure image, and estimate a size distribution of particles present in the material structure image based on a padded image which is an image obtained when a padding area is set for the material structure image, determine a size of the padding area to be set in the material structure image by determining a ratio between the maximum particle size and an image size representing the size of the padded image so that a fluctuation range of the estimation result of the maximum particle size when the size of the padding area is changed is equal to or less than a predetermined threshold, set the padding area of ​​the determined size for the material structure image to generate the padded material structure image, perform a Fourier transform on the generated padded material structure image, and calculate the size distribution of particles appearing in the material structure image based on the Fourier transform result which is the execution result.

[0013] An information processing program according to a sixth aspect is an information processing program for causing a computer to execute a process of acquiring a material structure image showing a material structure, acquiring a maximum particle size representing the size of the largest particle among particles appearing in the acquired material structure image, and estimating a size distribution of particles present in the material structure image based on a padded image which is an image obtained when a padding area is set for the material structure image, determining a ratio between the maximum particle size and an image size representing the size of the padded image so that a fluctuation range of the estimation result of the maximum particle size when the size of the padding area is changed is equal to or less than a predetermined threshold, determining a size of the padding area to be set in the material structure image by determining the ratio between the maximum particle size and an image size representing the size of the padded image so that a fluctuation range of the estimation result of the maximum particle size when the size of the padding area is changed is equal to or less than a predetermined threshold, generating the padded material structure image by setting the padding area of ​​the determined size for the material structure image, performing a Fourier transform on the generated padded material structure image, and calculating the size distribution of particles appearing in the material structure image based on the Fourier transform result which is the execution result. Effect of the Invention

[0014] As described above, according to the present disclosure, when estimating the size distribution of particles constituting a material from a material structure image using Fourier transform, it is possible to estimate the particle size distribution with high accuracy. [Brief description of the drawings]

[0015] [Figure 1] 1 is a schematic block diagram of an information processing apparatus according to an embodiment. [Diagram 2] FIG. 1 is a diagram for explaining an overview of an embodiment. [Diagram 3] FIG. 1 is a diagram for explaining an overview of an embodiment. [Figure 4] FIG. 13 is a diagram for explaining an estimation error of the size distribution of particles shown in a material structure image. [Diagram 5] FIG. 13 is a diagram for explaining the integrated value of the power spectrum obtained from the Fourier transform result when the size of the material structure image is changed. [Figure 6] FIG. 13 is a diagram for explaining the integrated value of the power spectrum obtained from the Fourier transform result when the size of the material structure image is changed. [Figure 7] FIG. 13 is a diagram for explaining a padded image. [Figure 8] FIG. 13 is a diagram for explaining saturation of the estimation accuracy of the size distribution of particles shown in a material structure image. [Figure 9] 11 is a diagram for explaining the relationship between the image size to be calculated and the calculation time of the Fourier transform. FIG. [Figure 10] FIG. 2 illustrates an example of a table stored in a database. [Figure 11] FIG. 2 illustrates an example of a table stored in a database. [Figure 12] FIG. 2 is a diagram illustrating an example of the configuration of a computer of an information processing device according to an embodiment. [Figure 13] 10 is a flowchart illustrating an example of processing performed by the information processing device according to the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] <Embodiment> Hereinafter, an information processing apparatus according to an embodiment will be described with reference to the drawings.

[0017] Fig. 1 is a block diagram showing an example of a functional configuration of an information processing device 10 according to an embodiment. As shown in Fig. 1, the information processing device 10 functionally includes an acquisition unit 100, a particle size acquisition unit 102, a database 103, a determination unit 104, a setting unit 106, and a calculation unit 108. The information processing device 10 according to the embodiment calculates the size distribution of particles appearing in a material structure image, which is an image captured when a material is observed using a microscope, from the material structure image.

[0018] Fig. 2 is an explanatory diagram for explaining the information processing device 10 of the embodiment. As shown in Fig. 2, the information processing device 10 of the embodiment calculates a size distribution D of particles appearing in a material structure image Im, which is an image captured when observing a material using a microscope, from the material structure image Im. If it is possible to obtain the size distribution D of particles appearing in the material structure image Im, it is possible to obtain information on the properties of the material corresponding to the material structure image Im based on the size distribution D.

[0019] FIG. 3 is a diagram for explaining the relationship between a material structure image and the frequencies contained in the material structure image. As shown in FIG. 3, a material structure image Im is generated by dividing an image signal I f1 ,I f2 ,I f3 These multiple image signals I f1 ,I f2 ,I f3 The superposition of these corresponds to the material structure image Im. In this case, by performing a Fourier transform, which is an example of frequency analysis, on the material structure image Im, a Fourier transform result FFT as shown in FIG. 3 is obtained. Note that the pixel values ​​of the image corresponding to the Fourier transform result FFT in FIG. 3 represent the power spectrum, and the higher the pixel value, the higher the value of the power spectrum. The power spectrum values ​​from A to B shown in FIG. 3 are extracted from the Fourier transform result FFT shown in FIG. 3. At that time, the straight line from A to B is rotated in the R direction, and the value obtained by accumulating the power spectrum values ​​obtained at each position is obtained as the power spectrum integrated value PS. It is also possible to obtain the size distribution of particles captured in the material structure image using such a Fourier transform result.

[0020] Note that there may be an error between the size distribution of particles in a material structure image estimated by directly performing a Fourier transform on the material structure image and the actual size distribution of particles in the material structure image. This point will be explained with reference to Figure 4.

[0021] As shown in FIG. 4, the integrated value PS of the power spectrum is obtained from the Fourier transform result FFT of the pseudo material structure image Imp. The integrated value of the power spectrum obtained by the estimation process based on the Fourier transform result FFT of the pseudo material structure image Imp corresponds to "estimated" in FIG. 4. In contrast, the theoretical value of the integrated value of the power spectrum obtained from the Fourier transform result corresponding to the actual particles shown in the pseudo material structure image Imp corresponds to "particle integrate" in FIG. 4. For this reason, an error may occur between the particle size distribution estimated by directly Fourier transforming the pseudo material structure image Imp and the actual particle size distribution shown in the pseudo material structure image Imp. As shown in FIG. 4, the mode in the estimated particle size distribution D is S, whereas the mode in the actual particle size distribution is Sr.

[0022] Such errors are caused by the ratio between the size of the material structure image and the size of the grains in the material structure image. Figure 5 shows a diagram for explaining the relationship between the ratio between the size of the material structure image and the grain size and the integrated value of the power spectrum obtained from the Fourier transform result.

[0023] As shown in FIG. 5, the integrated value of the power spectrum obtained from the pseudo material structure image Imp1 (indicated as "intensity small" in the figure) is different from the integrated value of the power spectrum obtained from the pseudo material structure image Imp2 (indicated as "intensity large" in the figure). The size of the two particles captured in the pseudo material structure image Imp1 and the size of the two particles captured in the pseudo material structure image Imp2 are both about 4 μm. On the other hand, the size of the pseudo material structure image Imp1 is 16 μm × 16 μm, while the size of the pseudo material structure image Imp2 is 50 μm × 50 μm. Therefore, the larger the size of the material structure image is relative to the size of the particle, the more accurate the Fourier transform result can be obtained, and the particle size can be estimated with high accuracy.

[0024] Figure 6 shows the integrated value of the power spectrum obtained from the Fourier transform result when the size (indicated as pixel100 in the figure, etc.) of the material structure image showing a particle of size 20 pixels (indicated as rsize20 in the figure) is changed. As shown in Figure 6, it can be seen that the larger the size of the material structure image, the higher the accuracy of the integrated value of the power spectrum obtained from the Fourier transform result.

[0025] For this reason, the information processing device 10 of this embodiment sets a padding region P in the original material structure image to generate a padded image Imx, as shown in Fig. 7. This increases the size of the material structure image, improving the estimation accuracy of the size distribution of particles appearing in the original material structure image. Note that, for example, a pixel value of 0 is set to each pixel in the padding region P.

[0026] However, on the other hand, the larger the size of the image to be analyzed, the higher the calculation cost becomes, and the longer the calculation time required to estimate the particle size distribution becomes, which can be a problem.

[0027] Figure 8 is a diagram for explaining the saturation of the estimation accuracy of the size distribution of particles seen in a material structure image. In Figure 8, 1 pixel corresponds to 10 nm in the material structure image to be analyzed. The size of the largest particle seen in the material structure image is hereinafter also referred to as the "maximum particle size."

[0028] "d40pixel" in Fig. 8 indicates that the maximum particle size (diameter of the maximum particle) shown in the material structure image corresponds to 40 pixels, "d80pixel" indicates that the maximum particle size shown in the material structure image corresponds to 80 pixels, and "d160pixel" indicates that the maximum particle size shown in the material structure image corresponds to 160 pixels. Additionally, "400nm", "800nm", and "1600nm" in Fig. 8 indicate the true values ​​of the maximum particle sizes.

[0029] The horizontal axis of the graph on the left side of FIG. 8 represents the size of one side of the padded material structure image generated by setting a padding region for the material structure image. The vertical axis of the graph on the left side of FIG. 8 represents the maximum particle size. The horizontal axis of the graph on the right side of FIG. 8 represents the ratio obtained by dividing the size of the largest particle shown in the material structure image by the size of one side of the padded material structure image. The vertical axis of the graph on the right side of FIG. 8 represents the maximum particle size.

[0030] As shown in the graph on the left of Figure 8, the larger the size of one side of the padded material structure image, the closer the estimated maximum particle size ("d40pixel", "d80pixel", and "d160pixel" in the figure) is to the true value ("400nm", "800nm", and "1600nm" in the figure).

[0031] Furthermore, as shown in the graph on the right side of Figure 8, the smaller the ratio obtained by dividing the size of the largest particle in the material structure image by the size of one side of the padded material structure image, the closer the estimated maximum particle size ("d40pixel", "d80pixel", and "d160pixel" in the figure) is to the true value ("400nm", "800nm", and "1600nm" in the figure).

[0032] In this way, the larger the size of the image to be analyzed, the more accurate the estimation of the size distribution of particles in the material structure image can be, but the estimation accuracy saturates. In the example shown in Figure 8, at point T where the ratio is about 0.1, it can be seen that the fluctuation range of the estimation result of the maximum particle size has almost converged.

[0033] Therefore, when changing the size of the padding area, the information processing device 10 of this embodiment determines the size of the padding area to be set in the material structure image by determining the ratio between the maximum particle size and the image size including the padding area so that the fluctuation range of the estimated result of the size of the largest particle appearing in the material structure image is below a predetermined threshold.

[0034] Specifically, in this embodiment, the ratio between the maximum particle size and the image size of the padded material structure image is stored in advance in the database 103 for each maximum particle size. Then, the information processing device 10 of this embodiment acquires the ratio between the maximum particle size and the image size of the padded material structure image from the database 103 according to the maximum particle size of the particles appearing in the material structure image, and determines the size of the padding area based on the ratio. The information processing device 10 generates a padded material structure image by adding a padding area of ​​the determined size to the material structure image. Then, the information processing device 10 of this embodiment estimates the size distribution of particles appearing in the material structure image by Fourier transforming the generated padded material structure image. This makes it possible to accurately estimate the size distribution of particles appearing in the material structure image.

[0035] Depending on the image size of the calculation target, the calculation speed may decrease due to the nature of the Fourier transform. Figure 9 shows a diagram for explaining the relationship between the image size of the calculation target and the calculation time of the Fourier transform. As shown in Figure 9, when performing Fourier transform on actual image data, the calculation time required for the Fourier transform increases by about 5 to 6 times if the image size of the analysis target increases by just a few pixels.

[0036] In the graph shown in Fig. 9, the horizontal axis represents the image size (the number of pixels on one side of the image) to be calculated, and the vertical axis represents the calculation time. As shown by the plot points in the graph in Fig. 9, we can see that the calculation time increases or decreases significantly when the image size to be calculated differs by just a few pixels.

[0037] For example, as shown in FIG. 9, assume that the calculation time required to calculate the Fourier transform of a material structure image of 2000 pixels is 0.1 seconds. When a padding region is set in this material structure image to make it approximately 10000 pixels, the calculation time is significantly different between plot point X and plot point Y, which are located near 10000 pixels. As shown in FIG. 9, the calculation time at plot point X is 13.2 seconds, whereas the calculation time at plot point Y is 2.6 seconds. Therefore, when a padding region is set in a material structure image of 2000 pixels to make it approximately 10000 pixels, the calculation time increases by 2.5 seconds for the image size corresponding to plot point Y (e.g., 10010 pixels), whereas the calculation time increases by 13.1 seconds for the image size corresponding to plot point X (e.g., 10000 pixels).

[0038] Therefore, the information processing device 10 of this embodiment refers to a table in which image sizes correspond to the calculation times (or calculation speeds) of the Fourier transform, and adjusts the image size of the padded material structure image. For example, when the information processing device 10 of this embodiment calculates that the image size of the padded material structure image is the image size corresponding to the X point in FIG. 9, the image size of the padded material structure image is adjusted so that it becomes the image size of the Y point, which is a slightly larger image size than the image size. By performing this adjustment, for example, in the example of FIG. 9, the calculation time can be reduced by 10.6 seconds. Therefore, by adjusting the image size of the padded material structure image, the size distribution of particles appearing in the material structure image can be accurately estimated while suppressing the calculation time. A specific description will be given below.

[0039] The acquisition unit 100 acquires a material structure image, which is an image captured when a material is observed using a microscope. The material structure image is an image that represents the structure of a material.

[0040] The particle size acquisition unit 102 acquires a maximum particle size, which represents the size of the largest particle among the particles appearing in the material structure image acquired by the acquisition unit 100, using a known image processing technique.

[0041] The database 103 stores, for example, a first table in which data on the ratio of the maximum particle size to the image size is associated with each maximum particle size. The database 103 also stores a second table in which the image size is associated with the calculation time of the Fourier transform. An example of the table stored in the database 103 is shown in Fig. 10 and Fig. 11.

[0042] In the first table shown in Fig. 10, when estimating the size distribution of particles present in a material structure image, the ratio of the maximum particle size to the image size is associated such that the fluctuation range of the estimation result of the maximum particle size when the size of the padding area added to the material structure image is changed is equal to or smaller than a predetermined threshold value. Note that the ratio of the maximum particle size to the image size is an example of data representing the relationship between the maximum particle size and the image size.

[0043] For example, as shown in FIG. 10, when the maximum particle size is 20 pixels, the appropriate ratio between the maximum particle size and the image size is 0.1, and the appropriate image size (length of one side) is 200 pixels. The appropriate ratio of 0.1 or the appropriate image size (length of one side) of 200 pixels is preset, for example, from the calculation result shown in FIG. 8. In FIG. 8, the estimation result of the maximum particle size varies depending on the maximum particle size, and an appropriate ratio or an appropriate image size that makes the fluctuation range equal to or smaller than a predetermined threshold value is stored in advance in the first table of the database 103. Meanwhile, the second table shown in FIG. 11 associates the image size with the calculation time of the Fourier transform. The use of these tables will be described later.

[0044] The determination unit 104 determines the ratio between the maximum particle size and the image size according to the maximum particle size acquired by the particle size acquisition unit 102, thereby determining the size of the padding region to be set in the material structure image.

[0045] Specifically, the determination unit 104 refers to the first table of the database 103, and obtains an appropriate ratio or an appropriate image size associated with the maximum particle size obtained by the particle size obtaining unit 102. Then, the determination unit 104 determines the size of the padding area according to the appropriate ratio or the appropriate image size associated with the maximum particle size.

[0046] For example, consider a case where the maximum particle size in the material structure image is 20 pixels and the material structure image is 128 pixels. In this case, the determination unit 104 refers to the first table of the database 103, and determines to add a padding region of 72 pixels to the material structure image by referring to an appropriate ratio of 0.1 or an appropriate image size of 200 pixels, which is associated with the maximum particle size of 20 pixels.

[0047] Furthermore, the determining unit 104 adjusts the size of the padding area according to the determined size of the padding area. Specifically, the determining unit 104 refers to the second table of the database 103 and adjusts the size of the padding area.

[0048] For example, consider the case where a padding area of ​​72 pixels is determined as described above and the image size to be analyzed is 200 pixels. In this case, the determination unit 104 refers to the second table of the database 103, compares the calculation time T2 associated with the image size of 200 pixels with the calculation times (T3, T4) of image sizes larger than 200 pixels (e.g., 200 pixels, 201 pixels, 202 pixels), and adjusts the size of the padding area so that the image size with the shortest calculation time is obtained. For example, when the calculation time T4 of the image size of 202 pixels is the shortest, the determination unit 104 adjusts the size of the padding area and determines the size of the padding area to be 74 pixels so that the image size is 202 pixels. This makes it possible to reduce the calculation time while maintaining the calculation accuracy.

[0049] The setting unit 106 generates a padded material structure image by setting a padding region of the size determined by the determination unit 104 for the material structure image acquired by the acquisition unit 100. For example, the setting unit 106 generates a padded material structure image with an image size of 202 pixels by setting a padding region of 74 pixels for the material structure image as described above.

[0050] The calculation unit 108 performs a Fourier transform on the padded material structure image generated by the setting unit 106, and calculates the size distribution of particles appearing in the material structure image based on the Fourier transform result that is the execution result. Specifically, the calculation unit 108 calculates the size distribution of particles appearing in the material structure image based on the Fourier transform result of the padded material structure image using the technology disclosed in JP2022-016172A.

[0051] A display unit (not shown) outputs the size distribution calculated by the calculation unit 108 as a result. A user of the information processing device 10 checks the size distribution result displayed on the display unit (not shown).

[0052] The information processing device 10 can be realized by, for example, a computer 50 as shown in Fig. 12. The computer 50 realizing the information processing device 10 includes a CPU 51, a memory 52 as a temporary storage area, and a non-volatile storage unit 53. The computer also includes an input / output interface (I / F) 54 to which an input / output device or the like (not shown) is connected, and a read / write (R / W) unit 55 that controls reading and writing of data from and to a recording medium 59. The computer also includes a network I / F 56 that is connected to a network such as the Internet. The CPU 51, the memory 52, the storage unit 53, the input / output I / F 54, the R / W unit 55, and the network I / F 56 are connected to one another via a bus 57.

[0053] The storage unit 53 can be realized by a hard disk drive (HDD), a solid state drive (SSD), a flash memory, etc. The storage unit 53 as a storage medium stores a program for making the computer function. The CPU 51 reads the program from the storage unit 53, expands it in the memory 52, and sequentially executes the processes contained in the program.

[0054] Next, the operation of the information processing device 10 of the embodiment will be described.

[0055] When a material structure image to be analyzed is input to the information processing device 10, the information processing device 10 executes an information processing routine shown in FIG.

[0056] In step S100, the acquisition unit 100 acquires an input material structure image.

[0057] In step S102, the particle size acquisition unit 102 acquires a maximum particle size, which represents the size of the largest particle among the particles appearing in the material structure image acquired in step S100, by using a known image processing technique.

[0058] In step S104, the determination unit 104 refers to the first table of the database 103 and determines the size of the padding region based on an appropriate ratio or an appropriate image size corresponding to the maximum particle size acquired in step S102. This determines the size of the padding region for accurately estimating the size distribution of particles captured in the material structure image.

[0059] In step S106, the determination unit 104 adjusts the size of the padding region determined in step S104 by referring to the second table of the database 103. This determines the size of the padding region for accurately estimating the size distribution of particles appearing in the material structure image while suppressing the calculation time.

[0060] In step S108, the setting unit 106 sets a padding region having the size adjusted in step S106 for the material structure image acquired in step S100, thereby generating a padded material structure image.

[0061] In step S110, the calculation unit 108 uses the technology disclosed in JP 2022-016172 A to calculate the size distribution of particles appearing in the material structure image based on the Fourier transform result for the padded material structure image obtained in step S108.

[0062] In step S112, the calculation unit 108 outputs the particle size distribution calculated in step S110 as a result.

[0063] As described above, the information processing device 10 according to the embodiment acquires a maximum particle size that represents the size of the largest particle among particles that appear in a material structure image that shows a material structure. When the information processing device 10 estimates the size distribution of particles present in the material structure image based on a padded image that is an image when a padding region is set for the material structure image, the information processing device 10 determines the size of the padding region to be set in the material structure image by determining the ratio between the maximum particle size and the image size that represents the size of the padded image so that the fluctuation range of the estimation result of the maximum particle size when the size of the padding region is changed is equal to or less than a predetermined threshold. The information processing device 10 generates a padded material structure image by setting a padding region of the determined size for the material structure image. The information processing device 10 performs a Fourier transform on the generated padded material structure image, and calculates the size distribution of particles appearing in the material structure image based on the Fourier transform result that is the execution result. This makes it possible to accurately estimate the size distribution of particles when estimating the size distribution of particles that constitute a material from a material structure image using a Fourier transform.

[0064] Specifically, the information processing device 10 of this embodiment acquires a first table, which is data showing the relationship between the maximum particle size and the image size, from a database according to the maximum particle size, and determines the size of the padding area according to the first table. This makes it possible to accurately estimate the size distribution of particles appearing in the material structure image.

[0065] 8, it can be seen that the larger the maximum particle size, which is the size of the largest particle among the particles appearing in the material structure image, the larger the size of the padding region where the fluctuation range of the estimation result of the maximum particle size converges. The information processing device 10 of this embodiment determines the size of the padding region using this maximum particle size, thereby making it possible to accurately estimate the size distribution of particles appearing in the material structure image.

[0066] Furthermore, the information processing device 10 of this embodiment determines the size of the padding region by referring to a second table, which is data showing the relationship between the image size and the calculation time of the Fourier transform, according to the image size of the padded image. This makes it possible to accurately estimate the size distribution of particles appearing in the material structure image while suppressing the calculation time.

[0067] In the above embodiment, the processes performed by each device have been described as software processes performed by executing a program, but they may be hardware processes. Alternatively, they may be a combination of both software and hardware processes. Furthermore, the programs stored in the ROM may be stored in various storage media and distributed.

[0068] Furthermore, the present invention is not limited to the above, and it goes without saying that various modifications can be made without departing from the spirit and scope of the present invention.

[0069] For example, the information processing device 10 of the above embodiment has been described with reference to the first table stored in the database 103 to determine the size of the padding region, but the present invention is not limited to this. For example, the information processing device 10 may determine the size of the padding region by gradually increasing the size of the padding region as shown in Fig. 8 and repeatedly calculating the ratio between the maximum particle size and the image size. In this case, the information processing device 10 sets the size of the padding region for the material structure image when the fluctuation range of the estimation result of the maximum particle size when the size of the padding region is changed becomes equal to or smaller than a predetermined threshold value.

[0070] In addition, for example, the database 103 of the information processing device 10 of the above embodiment has been described as storing the first table and the second table, but the present invention is not limited to this. The database 103 may store data in any format as long as the data is capable of determining the size of the padded image.

[0071] Furthermore, the second table of the database 103 of the information processing device 10 of the above embodiment may be further associated with a specific implementation form (for example, a type of program language, etc.), and the size of the padding area may be determined according to the form.

[0072] In addition, the information processing device 10 of the above embodiment has been described as an example in which the size distribution of particles appearing in the material structure image is calculated using the technology disclosed in JP 2022-016172 A, but is not limited thereto. The information processing device 10 may calculate the size distribution of particles appearing in the material structure image using other methods that utilize Fourier transform. [Explanation of symbols]

[0073] 10. Information processing device 50 Computer 100 Acquisition Department 102 Particle size acquisition unit 103 Database 104 Decision Section 106 Setting section 108 Calculation section

Claims

1. an acquisition unit for acquiring a material structure image showing the material structure; a particle size acquisition unit that acquires a maximum particle size representing the size of the largest particle among particles appearing in the material structure image acquired by the acquisition unit; a determination unit that determines the size of the padding area to be set in the material structure image by determining a ratio between the maximum particle size and an image size representing the size of the padded image so that a fluctuation range of the estimation result of the maximum particle size when the size of the padding area is changed is equal to or smaller than a predetermined threshold value when estimating a size distribution of particles present in the material structure image based on a padded image, which is an image obtained when a padding area is set in the material structure image; a setting unit that sets the padding region having the size determined by the determination unit in the material structure image to generate the padded material structure image; a calculation unit that performs a Fourier transform on the padded material structure image generated by the setting unit, and calculates a size distribution of particles appearing in the material structure image based on the Fourier transform result that is the execution result; An information processing device comprising:

2. the determination unit acquires data representing a relationship between the maximum particle size and the image size from a database in accordance with the maximum particle size, and determines a size of the padding area in accordance with the data representing the relationship; The information processing device according to claim 1 .

3. The determination unit determines the size of the padding area by repeatedly calculating a ratio between the maximum particle size and the image size. The information processing device according to claim 1 .

4. the determination unit obtains data representing a relationship between the image size and a calculation time of the Fourier transform from a database according to the image size, and determines a size of the padding area according to the data representing the relationship. The information processing device according to claim 1 .

5. Acquire a material structure image showing the material structure, A maximum particle size is obtained, which represents the size of the largest particle among the particles appearing in the obtained material structure image; when estimating a size distribution of particles present in the material structure image based on a padded image, which is an image obtained when a padding area is set for the material structure image, determining a size of the padding area to be set in the material structure image by determining a ratio between the maximum particle size and an image size representing the size of the padded image so that a fluctuation range of the estimation result of the maximum particle size when the size of the padding area is changed is equal to or smaller than a predetermined threshold value; generating the padded material structure image by setting the padding region of the determined size in the material structure image; performing a Fourier transform on the generated padded material structure image, and calculating a size distribution of particles appearing in the material structure image based on the Fourier transform result; An information processing method in which processing is performed by a computer.

6. Acquire a material structure image showing the material structure, A maximum particle size is obtained, which represents the size of the largest particle among the particles appearing in the obtained material structure image; when estimating a size distribution of particles present in the material structure image based on a padded image, which is an image obtained when a padding area is set for the material structure image, determining a size of the padding area to be set in the material structure image by determining a ratio between the maximum particle size and an image size representing the size of the padded image so that a fluctuation range of the estimation result of the maximum particle size when the size of the padding area is changed is equal to or smaller than a predetermined threshold value; generating the padded material structure image by setting the padding region of the determined size in the material structure image; performing a Fourier transform on the generated padded material structure image, and calculating a size distribution of particles appearing in the material structure image based on the Fourier transform result; An information processing program for causing a computer to execute processing.

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