JP2023137418A - Grain diameter measurement apparatus, method and program - Google Patents

Abstract

To provide a grain diameter measurement apparatus, method and program which can measure a grain diameter by recognizing only an object appearing on an upper part when the plurality of objects are piled up without extracting the spherical objects.SOLUTION: A grain diameter measurement apparatus D according to the present invention comprises: an imaging unit 1 which generates an image by imaging a plurality of spherical objects that are piled up; a binarizing processing unit 34 which generates a binarized image by binarizing the image generated by the imaging unit 1 on the basis of a luminance value; an extraction processing unit 38 which extracts a bright region in which the diameter of the bright region based on an area is within a prescribed range, and the circularity of the bright region is greater than a prescribed first threshold while the circularity of the bright region is greater than a prescribed second threshold from one or the plurality of bright regions in the binarized image generated by the binarizing processing unit 34; and an output unit 5 which outputs the diameter of the bright region extracted by the extraction processing unit 38 as the grain diameter of the object corresponding to the bright region extracted by the extraction processing unit 38.SELECTED DRAWING: Figure 1

Description

The present invention relates to a particle size measuring device, a particle size measuring method, and a particle size measuring program for measuring the particle size of deposited spherical objects.

Measurement of particle size (particle size) is required in various fields that handle particulate raw materials and products, for example, for setting manufacturing conditions and quality evaluation. For example, iron ore pellets, which are the raw material for blast furnaces, are produced by adding auxiliary raw materials and binders as necessary to powdered ore, which is the raw material for the pellets, and then adding a predetermined amount of moisture to produce raw pellets using a granulator. , is manufactured by drying and firing it. During the granulation stage of raw pellets, the particle size of raw pellets may fluctuate due to changes in granulation conditions such as the particle size of pellet raw materials, amount of supply, amount of added water, etc., and changes in the formation of deposits inside the granulator. It has been known. On the other hand, raw materials for blast furnaces are required to have uniform pellet diameters in order to ensure air permeability within the blast furnace. Therefore, the particle size of raw pellets granulated by a granulator is measured (for example, Patent Document 1 and Patent Document 2).

Patent No. 6099525 (Japanese Unexamined Patent Publication No. 2014-178300) Patent No. 6590072 (International Publication No. 2018/181942)

Incidentally, since the particles after granulation are transported to the next process or to a storage facility, it is preferable that the particle size of the particles be measured during transportation. In such a case, the so-called sieve test is not preferable because it is necessary to extract the particles during transport. Furthermore, since the particles being transported are usually deposited in several layers, when observed from above, the particles that are relatively present at the bottom appear smaller than their actual size. For this reason, it is preferable to identify only the particles exposed at the top, measure their particle sizes, and then represent the overall particle size.

The present invention has been made in view of the above-mentioned circumstances, and its purpose is to remove only the object exposed at the top when a plurality of objects are piled up, without removing the spherical object. An object of the present invention is to provide a particle size measuring device, a particle size measuring method, and a particle size measuring program that can recognize and measure particle sizes.

As a result of various studies, the present inventors have found that the above object can be achieved by the following present invention. That is, the particle size measuring device according to one aspect of the present invention includes an imaging unit that generates an image by imaging a plurality of deposited spherical objects, and an imaging unit that generates an image by imaging a plurality of deposited spherical objects, and an image that is generated by the imaging unit based on a luminance value. A binarization processing unit that binarizes and generates a binarized image; and a diameter of the bright area based on the area from among one or more bright areas in the binarized image generated by the binarization processing unit. is within a predetermined range, the circularity of the bright region is larger than a predetermined first threshold, and the circularity of the bright region is larger than a predetermined second threshold. a processing section; and an output section that outputs the diameter of the bright region extracted by the extraction processing section as a particle size of an object corresponding to the bright region extracted by the extraction processing section, It is the reciprocal of the aspect ratio, which is the ratio of the major axis length to the minor axis length, when the contour of the bright area is approximated as an ellipse, and the circularity is the area of the bright area divided by the square of the perimeter of the bright area. This is the result of multiplying the result of division by 4 times pi.

Such a particle size measuring device measures the particle size of a plurality of accumulated spherical objects based on images taken of the objects, so there is no need to extract the objects as in the sieve test. . In the particle size measuring device, the diameter of the bright region based on area is within a predetermined range, the circularity of the bright region is larger than a predetermined first threshold value, and the circularity of the bright region is within a predetermined range. Since the bright region larger than the predetermined second threshold is extracted, when a plurality of the objects are piled up, only the object exposed at the top can be recognized and the particle size can be measured.

In another aspect, the above-described particle size measuring device further includes an illumination unit that illuminates the plurality of objects.

Since such a particle size measuring device further includes an illumination section, it is possible to measure the particle size under a constant lighting environment, so it can measure not only a stationary subject but also a subject that is being transported or moving. Since sufficient illuminance is ensured, clear images can be generated by reducing the exposure time during imaging (that is, by increasing the shutter speed), and variations in measurement accuracy can be reduced.

In another aspect, these above-described particle size measuring devices further include a shading correction processing section that performs shading correction on the image generated by the imaging section before the binarization processing section performs binarization.

Since such a particle size measuring device further includes a shading correction processing section, even when there is spatial unevenness in illuminance, the unevenness in illuminance can be reduced and the particle size can be measured with higher accuracy.

In another aspect, these above-described particle size measuring devices further include a smoothing processing section that smoothes the image generated by the imaging section before the binarization processing section performs binarization.

Since such a particle size measuring device further includes a smoothing processing section, it is possible to reduce differences in brightness caused by the shape of the object surface, deposits, etc., and to measure the particle size with higher accuracy.

In another aspect, in these above-mentioned particle size measuring devices, before extraction in the extraction processing section, a separation processing section separates the bright region formed by connecting a plurality of spherical shapes into spherical bright regions. Furthermore, it is equipped with.

Since such a particle size measuring device further includes a separation processing section, even if a plurality of spherical shapes are connected, it can be separated, and the particle size can be measured with higher accuracy.

In another aspect, in the above-mentioned particle size measuring apparatus, before extraction in the extraction processing section, expansion processing is performed to expand the outer periphery of the bright region by a predetermined length outward in the radial direction, one or more times. The apparatus further includes an expansion processing section that performs the expansion process twice.

Such a particle size measuring device further includes an expansion processing section, so if the outer periphery of the object appears dark, the measurement will be smaller than the actual size, but even in such cases, the outer periphery of the bright area Since the particle size is expanded, the particle size can be measured closer to the actual size.

In another aspect, these above-described particle size measuring devices further include an ellipse approximation processing section that transforms the shape of the bright region into the most approximate elliptical shape before extraction by the extraction processing section.

Such a particle size measuring device further includes an ellipse approximation processing unit, so that the shape of a plurality of deposited spherical objects whose shape is difficult to see due to slight overlap is determined by ellipse approximation. It can be restored and the number of measurable objects can be increased.

A particle size measuring device according to another aspect of the present invention includes an image acquisition unit that acquires images of a plurality of deposited spherical objects, and a luminance value of the image acquired by the image acquisition unit. a binarization processor that generates a binarized image by binarizing based on the binarization processing unit; Extracting the bright region whose diameter is within a predetermined range, the circularity of the bright region is larger than a predetermined first threshold value, and the circularity of the bright region is larger than a predetermined second threshold value. an extraction processing section; and an output section that outputs the diameter of the bright region extracted by the extraction processing section as a particle size of an object corresponding to the bright region extracted by the extraction processing section, and the circularity is The circularity is the reciprocal of the aspect ratio, which is the ratio of the major axis length to the minor axis length, when the outline of the bright area is approximated as an ellipse, and the circularity is the area of the bright area divided by 2 of the perimeter of the bright area. This is the multiplication result obtained by multiplying the result of division by the multiplication factor by four times pi.

Such a particle size measuring device measures the particle size of a plurality of accumulated spherical objects based on images taken of the objects, so there is no need to extract the objects as in the sieve test. . In the particle size measuring device, the diameter of the bright region based on area is within a predetermined range, the circularity of the bright region is larger than a predetermined first threshold value, and the circularity of the bright region is within a predetermined range. Since the bright region larger than the predetermined second threshold is extracted, when a plurality of the objects are piled up, only the object exposed at the top can be recognized and the particle size can be measured.

A particle size measuring method according to another aspect of the present invention includes an imaging step of imaging a plurality of deposited spherical objects to generate an image, and an image generated in the imaging step based on a luminance value. A binarization processing step of binarizing to generate a binarized image, and a diameter of the bright region based on the area from among one or more bright regions in the binarized image generated in the binarization processing step. is within a predetermined range, the circularity of the bright region is larger than a predetermined first threshold, and the circularity of the bright region is larger than a predetermined second threshold. a processing step; and an output step of outputting the diameter of the bright region extracted in the extraction processing step as a particle size of an object corresponding to the bright region extracted in the extraction processing step, It is the reciprocal of the aspect ratio, which is the ratio of the major axis length to the minor axis length, when the contour of the bright area is approximated as an ellipse, and the circularity is the area of the bright area divided by the square of the perimeter of the bright area. This is the result of multiplying the result of division by 4 times pi.

A particle size measuring method according to another aspect of the present invention includes an image acquisition step of acquiring images of a plurality of deposited spherical objects, and converting the images acquired in the image acquisition step into luminance values. A binarization processing step of generating a binarized image by binarizing based on the binarization processing step; Extracting the bright region whose diameter is within a predetermined range, the circularity of the bright region is larger than a predetermined first threshold value, and the circularity of the bright region is larger than a predetermined second threshold value. an extraction step; and an output step of outputting the diameter of the bright region extracted in the extraction step as a particle size of an object corresponding to the bright region extracted in the extraction step, and the roundness is The circularity is the reciprocal of the aspect ratio, which is the ratio of the major axis length to the minor axis length, when the outline of the bright area is approximated as an ellipse, and the circularity is the area of the bright area divided by 2 of the perimeter of the bright area. This is a computer-implemented method in which the multiplication result is the multiplication result of dividing the multiplier by four times pi.

A particle size measurement program according to another aspect of the present invention includes an image acquisition step of acquiring images of a plurality of deposited spherical objects, and converts the images acquired in the image acquisition step into luminance values. A binarization processing step of generating a binarized image by binarizing based on the binarization processing step; Extracting the bright region whose diameter is within a predetermined range, the circularity of the bright region is larger than a predetermined first threshold value, and the circularity of the bright region is larger than a predetermined second threshold value. an extraction step; and an output step of outputting the diameter of the bright region extracted in the extraction step as a particle size of an object corresponding to the bright region extracted in the extraction step, and the roundness is The circularity is the reciprocal of the aspect ratio, which is the ratio of the major axis length to the minor axis length, when the outline of the bright area is approximated as an ellipse, and the circularity is the area of the bright area divided by 2 of the perimeter of the bright area. This is a program executed by a computer that is a multiplication result of multiplying the division result by 4 times pi.

Such a particle size measurement method and particle size measurement program measure the particle size of a plurality of deposited spherical objects based on images taken of the objects. There is no need to remove it. The particle size measuring method and the particle size measuring program are such that the diameter of the bright region based on area is within a predetermined range, the roundness of the bright region is greater than a predetermined first threshold, and Since the bright region in which the circularity of the region is larger than the predetermined second threshold value is extracted, when a plurality of the objects are piled up, only the object exposed at the top can be recognized and the particle size can be measured.

The particle size measuring device, the particle size measuring method, and the particle size measuring program according to the present invention detect only the objects exposed at the top when a plurality of objects are piled up without removing the spherical objects. Can be recognized and measured particle size.

It is a block diagram showing the composition of the particle size measuring device in an embodiment. FIG. 3 is a diagram for explaining the arrangement of an imaging section and an illumination section in the particle size measuring device. FIG. 3 is a diagram for explaining shading correction performed by the particle size measuring device. FIG. 3 is a diagram for explaining an expansion process executed by the particle size measuring device. As an example, it is a diagram showing the processing results of performing the expansion processing twice. FIG. 3 is a diagram for explaining ellipse approximation processing performed by the particle size measuring device. It is a flow chart showing the operation of the particle size measuring device. FIG. 6 is a diagram for explaining the results when only binarization processing and extraction processing are performed. FIG. 6 is a diagram for explaining the results when only binarization processing, dilation processing, and extraction processing are performed. FIG. 6 is a diagram for explaining the results when only binarization processing, dilation processing, ellipse approximation processing, and extraction processing are performed. FIG. 3 is a diagram showing the correlation between the particle size determined by the particle size measuring device and the actually measured particle size. FIG. 2 is a diagram for explaining an example.

Hereinafter, one or more embodiments of the present invention will be described with reference to the drawings. However, the scope of the invention is not limited to the disclosed embodiments. It should be noted that structures with the same reference numerals in each figure indicate the same structure, and the description thereof will be omitted as appropriate. In this specification, when referring to a general term, a reference numeral without a subscript is used, and when referring to an individual configuration, a reference numeral with a suffix is used.

The particle size measuring device in the embodiment is a device that measures the particle size of a plurality of deposited spherical objects. This particle size measuring device includes an imaging unit that images a plurality of accumulated spherical objects and generates an image, and a binarized image that binarizes the image generated by the imaging unit based on a luminance value. and a binarization processing unit that generates a binarization processing unit, and a diameter of the bright area based on the area is within a predetermined range from one or more bright areas in the binarized image generated by the binarization processing unit. , and an extraction processing section that extracts the bright region in which the circularity of the bright region is larger than a predetermined first threshold value, and the circularity of the bright region is larger than a predetermined second threshold value; and an output section that outputs the diameter of the bright region extracted by the extraction processing section as the particle size of the object corresponding to the bright region extracted by the extraction processing section. The roundness is the reciprocal of the aspect ratio, which is the ratio of the major axis length to the minor axis length, when the outline of the bright region is approximated to an ellipse. The degree of circularity is the result of multiplying the area of the bright region by the square of the perimeter of the bright region multiplied by four times the circumference. Hereinafter, such a particle size measuring device, a particle size measuring method and a particle size measuring program implemented therein will be explained using an example applied to the construction process of a blast furnace. The present invention is not limited to iron ore pellets, but may be any deposited, spherical object (for example, raw materials, products, etc.).

FIG. 1 is a block diagram showing the configuration of a particle size measuring device in an embodiment. FIG. 2 is a diagram for explaining the arrangement of an imaging section and an illumination section in the particle size measuring device. FIG. 3 is a diagram for explaining shading correction performed by the particle size measuring device. FIG. 4 is a diagram for explaining the expansion process executed by the particle size measuring device. FIG. 4A shows, as an example, a binarized image to be subjected to expansion processing, and FIG. 4B shows an image resulting from the expansion processing of the binarized image shown in FIG. 4A. FIG. 5 is a diagram showing, as an example, the results of performing the expansion process twice. FIG. 5A shows, as an example, a binarized image to be subjected to dilation processing, FIG. 5B shows an image resulting from the dilation processing of the binarized image shown in FIG. 5A, and FIG. An image resulting from further expansion processing of the image shown in FIG. The image shown in FIG. 5A is the same as the binarized image shown in FIG. 4A, and therefore the image shown in FIG. 5B is the same as the image shown in FIG. 4B. FIG. 6 is a diagram for explaining the ellipse approximation process executed by the particle size measuring device.

For example, as shown in FIGS. 1 and 2, the particle size measuring device D in the embodiment includes an imaging section 1, an illumination section 2 (2-1, 2-2), a control processing section 3, and an input section 4. , an output section 5 , an interface section (IF section) 6 , and a storage section 7 .

The imaging unit 1 is a device that is connected to the control processing unit 3 and generates an image by imaging a plurality of accumulated spherical objects under the control of the control processing unit 3. The imaging unit 1 includes, for example, an imaging optical system that forms an optical image of the imaging target on a predetermined imaging plane, and is arranged with a light receiving surface aligned with the imaging plane, and electrically converts the optical image of the imaging target. The digital camera is equipped with an area image sensor that converts the output of the area image sensor into a digital signal, and an image processing unit that generates image data representing an image of the imaging target by image processing the output of the area image sensor. The imaging unit 1 may be a color digital camera, but as described later, in this embodiment, the luminance value of the image is binarized, so it may be a monochrome digital camera.

The illumination unit 2 is a device that is connected to the control processing unit 3 and illuminates the plurality of deposited spherical objects under the control of the control processing unit 3. Note that the lighting section 2 may be turned on and off by manual operation without being connected to the control processing section 3.

In the blast furnace granulation process, for example, a pan-type or drum-type granulator is provided. The granulator is supplied with a raw material for granulation, which is powdered ore as a raw material, mixed with auxiliary materials as necessary, and a binder such as quicklime or bentonite, and a predetermined amount of water added. By rotating the machine at a predetermined inclination angle and rotation speed, the granulation raw material is granulated into green pellets. The raw pellets Ob discharged from the granulator are carried out by a carrying conveyor BC, and after being sieved to a predetermined particle size width via a vibrating sieve, the raw pellets Ob are sent to a baking oven such as a great kiln for drying and baking. Transported to the furnace (sintering machine).

In the present embodiment, the particle size measuring device D is used, for example, in the granulation process of such a blast furnace. More specifically, as shown in FIG. 2, a plurality of deposited raw pellets (an example of the plurality of deposited spherical objects) Ob are conveyed on the conveyor BC from above, The optical axis is arranged along the normal direction of the conveyance surface of the conveyor BC (up and down direction in the paper plane of FIG. 2, Z direction) so that the image is taken from directly above, and the illumination unit 2 illuminates the raw pellets Ob. It is arranged so that it is illuminated diagonally from above. In the example shown in FIG. 2, the illumination unit 2 includes two first and second illumination units 2-1 and 2-2, and includes two first and second illumination units 2-1 and 2-2 in the conveyance direction of the carry-out conveyor BC (the depth direction in the paper plane of FIG. 2, the X direction). ) and the direction perpendicular to the normal direction of the conveyance surface (the left-right direction in FIG. 2, the Y direction), with the imaging unit 1 interposed therebetween. In this way, the pair of illumination units 2-1 and 2-2 from the left and right sides of the imaging unit 1 illuminate the raw pellets Ob on the unloading conveyor BC with such brightness that the brightness changes depending on the presence or absence of the raw pellets Ob. By intentionally illuminating the raw pellet Ob so as to generate a shadow, the brightness change in the raw pellet Ob to be measured can stably appear. Since sufficient illuminance is ensured even when the subject is being transported or moving, clear images can be generated by reducing the exposure time during imaging. Therefore, since the particle size measuring device D can measure the particle size under such a constant lighting environment, variations in measurement accuracy can be reduced. In addition, in order to prevent so-called stray light, a light shielding member (for example, a blackout curtain, etc.) is provided to cover the first and second lighting sections 2-1 and 2-2 and shields light from the outside. It's okay to be hit.

The input unit 4 is connected to the control processing unit 3, and inputs various commands such as a command to start particle size measurement, and information for operating the particle size measuring device D, such as the date of measurement. It is a device for inputting various necessary data to the particle size measuring device D, and includes, for example, a plurality of input switches, a keyboard, a mouse, etc., to which predetermined functions are assigned. The output unit 5 is a device that is connected to the control processing unit 3 and outputs commands and data input from the input unit 4 and particle diameters determined by the particle size measuring device D according to the control of the control processing unit 3. For example, display devices such as a CRT display, LCD (liquid crystal display), and organic EL display, printing devices such as printers, etc.

Note that the input section 4 and the output section 5 may be constructed from a touch panel. When configuring this touch panel, the input section 4 is a position input device that detects and inputs an operating position, such as a resistive film type or a capacitive type, and the output section 5 is a display device. In this touch panel, a position input device is provided on the display surface of the display device, one or more input content candidates that can be input are displayed on the display device, and the user touches the display position where the input content that the user wants to input is displayed. Then, the position is detected by the position input device, and the display content displayed at the detected position is input to the particle size measuring device D as the user's operation input content. With such a touch panel, it is easy for the user to intuitively understand the input operations, so that the particle size measuring device D is provided that is easy for the user to handle.

The IF section 6 is a circuit that is connected to the control processing section 3 and inputs/outputs data to/from external equipment under the control of the control processing section 3, for example, using RS-232C, which is a serial communication method. These include an interface circuit, an interface circuit using the Bluetooth (registered trademark) standard, an interface circuit using the USB standard, and the like. Furthermore, the IF unit 6 may be a communication interface circuit that transmits and receives communication signals to and from external equipment, such as a data communication card or a communication interface circuit that complies with the IEEE802.11 standard.

The storage section 7 is a circuit that is connected to the control processing section 3 and stores various predetermined programs and various predetermined data under the control of the control processing section 3. The various predetermined programs include, for example, a control processing program, and the control processing program may include, for example, controlling each section 1, 2, 4 to 7 of the particle size measuring device D, depending on the function of each section. A control program that controls, a binarization processing program that binarizes the image generated by the imaging unit 1 based on the luminance value and generates a binarized image, and a binarization image generated by the binarization processing program. Among one or more bright regions in , the diameter of the bright region based on area is within a predetermined range, and the circularity of the bright region is greater than a predetermined first threshold, and an extraction processing program that extracts the bright region whose circularity is larger than a predetermined second threshold; and shading that performs shading correction on the image generated by the imaging unit 1 before binarization with the binarization processing program. A correction processing program, a smoothing processing program for smoothing the image generated by the imaging unit 1 before binarization by the binarization processing program, and a plurality of spheres before extraction by the extraction processing program. A separation processing program that separates the bright region consisting of connected shapes into spherical bright regions, or before extraction using the extraction processing program, moves the outer periphery of the bright region radially outward by a predetermined length. This includes an expansion processing program that performs expansion processing once or multiple times, and an ellipse approximation processing program that transforms the shape of the bright region into the most approximate elliptical shape before extraction by the extraction processing program. . The various kinds of predetermined data include, for example, the image captured by the imaging unit 1, the predetermined range (its lower limit value and upper limit value), the first threshold value, the second threshold value, etc. Contains the data required above. Such a storage unit 7 includes, for example, a ROM (Read Only Memory) that is a nonvolatile storage element, an EEPROM (Electrically Erasable Programmable Read Only Memory) that is a rewritable nonvolatile storage element, and the like. The storage unit 7 includes a RAM (Random Access Memory), which serves as a so-called working memory of the control processing unit 3 that stores data generated during execution of the predetermined program. Furthermore, the storage unit 7 may be configured to include a hard disk device with a relatively large storage capacity.

The control processing section 3 is a circuit for controlling each section 1, 2, 4 to 7 of the particle size measuring device D according to the function of each section, and determining the particle size of a spherical object. The control processing unit 3 includes, for example, a CPU (Central Processing Unit) and its peripheral circuits. By executing the control processing program, the control processing section 3 includes a control section 31, a shading correction processing section 32, a smoothing processing section 33, a binarization processing section 34, a separation processing section 35, an expansion processing section 36, and an ellipse processing section. It functionally includes an approximation processing section 37 and an extraction processing section 38. The particle size of the spherical object is determined by the extraction processing unit 38 during an extraction process in which the spherical object is recognized and extracted as described later.

The control section 31 controls the respective sections 1, 2, 4 to 7 of the particle size measuring apparatus D according to the functions of the respective sections, and manages the overall control of the particle size measuring apparatus D.

The binarization processing unit 34 binarizes the image generated by the imaging unit 1 based on the luminance value to generate a binarized image. The binarization processing unit 34 will be described later.

The extraction processing unit 38 selects one or more bright regions in the binarized image generated by the binarization processing unit 34, and the diameter of the bright region based on the area is within a predetermined range, and The bright region whose roundness is larger than a predetermined first threshold value and whose circularity is larger than a predetermined second threshold value is extracted. The extraction processing unit 38 will be described later.

The shading correction processing section 32 performs shading correction on the image generated by the imaging section 1 before the binarization processing section 34 performs binarization. The shading correction is for correcting uneven brightness caused by the optical system used to generate the image. In this embodiment, for example, as shown in FIG. 3, the shading correction processing unit 32 subtracts a first smoothed image SP1 obtained by smoothing the input image IP1 from the input image IP1, and adds the above-mentioned By adding the average brightness image AP of the input image IP1, a shading corrected image CP is generated by shading correcting the input image IP1. In this embodiment, the input image IP1 is an image generated by the imaging section 1.

The first smoothed image SP1 is generated, for example, by filtering the input image IP1 using an averaging filter of an image filter that performs simple averaging. When the first smoothed image SP1 is generated by filtering processing using this averaging filter, if the pixel position of the image of interest to be image-processed is (x, y), the pixel value a'(x, y) after image processing is ) is determined by the following equation 1.

ここで、Ｘは、着目画素から見た平均化フィルタの横方向の画素範囲であり、Ｙは、前記着目画素から見た前記平均化フィルタの縦方向の画素範囲である。ｋは、前記平均化フィルタの縦方向および横方向のサイズであり、入力画像の縦方向および横方向より十分に小さい適宜な値に設定される。

Here, X is a pixel range in the horizontal direction of the averaging filter as seen from the pixel of interest, and Y is a pixel range in the vertical direction of the averaging filter as seen from the pixel of interest. k is the size of the averaging filter in the vertical and horizontal directions, and is set to an appropriate value that is sufficiently smaller than the vertical and horizontal directions of the input image.

Alternatively, for example, the first smoothed image SP is generated by filtering the input image IP1 using a Gaussian filter, which is an image filter using a Gaussian function. The average brightness image AP is an image in which the average brightness value of each pixel in the input image IP1 is determined as an average brightness value, and this average brightness value is used as the pixel value of each pixel.

The smoothing processing section 33 smoothes the image generated by the imaging section 1 before the binarization processing section 34 performs binarization. In this embodiment, since the image generated by the imaging unit 1 is smoothed after shading correction, the smoothing processing unit 33 smoothes the luminance value of the shading corrected image, which has been subjected to shading correction by the shading correction processing unit 32. A second smoothed image is generated by smoothing the shading corrected image using the smoothing filter of the image filter. An averaging filter or a Gaussian filter is used as the smoothing filter.

The binarization processing unit 34 binarizes the second smoothed image smoothed by the smoothing processing unit 33 based on the luminance value, and generates a binarized image by binarizing the second smoothed image. do. For this binarization, for example, so-called Otsu binarization processing is used. This Otsu binarization process calculates the histogram of the image to be binarized (the input image, here the second smoothed image), and when the histogram is divided into two, the variance of one side and the variance between the two are calculated. This is a process in which the ratio of the histogram is defined as the degree of separation, and the class of the histogram at the bisecting position, where the degree of separation is maximum, is binarized as a threshold value.

The separation processing section 35 separates the bright region formed by connecting a plurality of spherical shapes into spherical bright regions (contour separation) before extraction by the extraction processing section 38 . In this embodiment, the separation processing unit 35 converts the binarized image binarized by the binarization processing unit 34 into the bright region formed by connecting a plurality of spherical shapes by using the so-called watershed method. is separated into spherical bright regions. This Watershed method considers the target image (input image, here the binarized image) as a topographical structure, and creates an image by simulating the state transition when the topographical structure is filled with water in order from the lowest point. This method performs area segmentation.

The separation processing unit 35 performs a labeling process of sequentially assigning an integer serial number starting from 1 to each of the separated bright areas in order to specify and identify each of the separated bright areas. Each number assigned to each bright area in this labeling process becomes an identifier (ID, serial number) for specifying and identifying the bright area.

The expansion processing section 36 performs expansion processing for expanding the outer periphery of the bright region by a predetermined length outward in the radial direction, once or multiple times, before the extraction processing section 38 performs extraction. In this embodiment, this expansion process is performed for each bright area separated by the separation processing unit 35 and assigned a serial number. More specifically, for example, for each pixel belonging to a bright region, the expansion processing unit 36 sets one pixel located at the front, rear, right, and left sides of the pixel as a bright region. That is, the pixel value 0 representing black is changed to the pixel value 1 representing white, and the area is defined as a bright area. In other words, for each pixel located on the outer periphery of the bright area, one pixel located outside the pixel in the front-rear direction (vertical direction) is defined as the bright area, and one pixel outside the pixel in the left-right direction (horizontal direction) is defined as the bright area. One pixel located at is defined as a bright area. In one example, when the dilation process is performed on the first pixel PX1 belonging to the first bright area LA1 in the input image IP2 shown in FIG. 4A, as shown in FIG. Each pixel in the image is changed from its pixel value of 0 to its pixel value of 1, and becomes a bright region. As a result, in the input image IP2, the first bright area LA1 is an area consisting of one first pixel PX1, but is expanded into an area ELA1 consisting of five pixels by the expansion process. Similarly, the second bright area LA2 in the input image IP2 shown in FIG. 4A was an area consisting of eight pixels PX21 to PX28, but due to expansion processing, it became an area consisting of 19 pixels as shown in FIG. 4B. It is expanded to area ELA2. When the image shown in FIG. 4B that has been subjected to the expansion process once is further subjected to the expansion process, the image shown in FIG. 5C (an image that has been subjected to the expansion process twice) is obtained. The image shown in FIG. 5A is the same as the image shown in FIG. 4A, and the image shown in FIG. 5B is the same as the image shown in FIG. 4B. In this example, the predetermined length is the length of one pixel, but it is not limited to this, and may be used to calculate the difference between the size of the image of the object reflected in the image and the actual size. It may be set as appropriate depending on the consideration. In addition, in this example, the expansion process was performed twice, but the expansion process is not limited to this. May be set to .

Note that as shown in FIG. 5C, due to the expansion process, overlapping pixels occur in the first bright area LA1 and second bright area LA2, but the first bright area LA1 and second bright area LA2 are different from each other as described above. In addition, since they are distinguished by serial number and expanded individually, as a result of the expansion process, they only appear to overlap and are not integrated.

The ellipse approximation processing section 37 transforms the shape of the bright region into the most approximate ellipse shape before the extraction processing section 38 extracts it. In this embodiment, the ellipse approximation processing unit 37 is executed for each bright region expanded by the expansion processing unit 36. More specifically, for example, as shown in FIG. 6, the ellipse approximation processing unit 37 first calculates, for each pixel PXi belonging to the bright area LA3, the distance from the pixel PXi to the ellipse EL. Next, the ellipse approximation processing unit 37 calculates the sum of the distances for each pixel PXi belonging to the bright area LA3 as an error function δ. Then, the ellipse approximation processing unit 37 solves for the ellipse EL that minimizes the obtained error function δ, for example, by least squares estimation. As a result, the ellipse EL that most closely approximates the bright area AL3 is found.

The extraction processing section 38 selects a bright region from among the bright regions transformed into an elliptical shape by the ellipse approximation processing section 37, the diameter of the bright region based on the area is within a predetermined range, and the bright region is a perfect circle. The bright region whose circularity is larger than a predetermined first threshold and whose circularity is larger than a predetermined second threshold is extracted. The diameter R of the bright region based on the area S is determined as the grain size R of the spherical object by dividing the area S by the pi ratio and multiplying the square root of the result (R= 2×(S/π) ^1/2 ). Since the bright region is deformed (approximated) into an elliptical shape, the area S is determined by the formula for calculating the area of an ellipse (S=π×a×b, a: major axis length, b: minor axis length) . Note that the area S may be determined by determining the number of pixels belonging to the bright region before it is transformed into an elliptical shape. The circularity TC is the reciprocal of the aspect ratio (=b/a) which is the ratio of the major axis length b to the minor axis length a when the outline of the bright region is approximated as an ellipse (TC=a/b ). The degree of circularity CD is the result of dividing the area S of the bright region by the square of the perimeter l of the bright region, multiplied by four times the circumference (CD=4×π ×S/l ² ).

More specifically, first, the extraction processing unit 38 selects one bright region from among the bright regions transformed into an elliptical shape by the ellipse approximation processing unit 37. Next, the extraction processing unit 38 determines the diameter R in this selected bright region. Next, the extraction processing unit 38 obtains each of the circularity TC and the circularity CD in the selected bright region. Then, the extraction processing unit 38 determines whether or not the selected bright region satisfies the determination condition for determining whether the bright region is a particle. The judgment condition is that the diameter R of the bright region based on the area S is within a predetermined range (Thd<R<Thu, Thd; the lower limit of the predetermined range; Thu: the upper limit of the predetermined range). and the circularity TC of the bright region is larger than a predetermined first threshold Th1 (TC>Th), and the circularity CD of the bright region is larger than a predetermined second threshold Th2 (CD> Th2). As a result of the determination, if Thd<R<Thu, TC>Th, and CD>Th2, the extraction processing unit 38 determines that the selected bright region is a particle, and A bright region is extracted as the spherical object. On the other hand, if at least one of Thd<R<Thu, TC>Th, and CD>Th2 does not hold as a result of the determination, the extraction processing unit 38 determines that the selected bright region is not a particle. The selected bright region is not extracted as the spherical object. The extraction processing unit 38 performs such processing for each bright region transformed into an elliptical shape by the ellipse approximation processing unit 37. The upper limit Thd, the lower limit Thu, the first threshold Th1, and the second threshold Th2 are appropriately set in advance from, for example, a plurality of samples.

The control unit 31 outputs the diameter R of the bright region extracted by the extraction processing unit 38 from the output unit 5 as the particle size of the object corresponding to the bright region extracted by the extraction processing unit 38.

These control processing unit 3, input unit 4, output unit 5, F unit 6, and storage unit 7 can be configured by, for example, a desktop computer, a notebook computer, or the like. The computers composing each of these parts 3 to 7 may be placed in an operation room in a granulation process plant, and may be incorporated into a console (may also be used as a console), or may be separate from the console. good.

Next, the operation of this embodiment will be explained. FIG. 7 is a flowchart showing the operation of the particle size measuring device. FIG. 8 is a diagram for explaining the results when only the binarization process and the extraction process are performed. FIG. 9 is a diagram for explaining the results when only binarization processing, dilation processing, and extraction processing are performed. FIG. 10 is a diagram for explaining the results when only binarization processing, dilation processing, ellipse approximation processing, and extraction processing are performed. FIG. 11 is a diagram showing the correlation between the particle size determined by the particle size measuring device and the actually measured particle size. The horizontal axis in FIG. 11 is the particle size determined by the particle size measuring device D, and the vertical axis is the particle size actually measured using a sieve. FIG. 12 is a diagram for explaining one embodiment.

When the particle size measuring device D having such a configuration is turned on, necessary parts are initialized and the particle size measuring device D starts operating. The control processing section 3 includes a control section 31, a shading correction processing section 32, a smoothing processing section 33, a binarization processing section 34, a separation processing section 35, an expansion processing section 36, and an ellipse approximation processing section by executing the control processing program. A processing section 37 and an extraction processing section 38 are functionally configured.

During granulation, the particle size measuring device D carries out each process shown in FIG. This is repeated and the particle size of the raw pellet Ob is measured in approximately real time.

In FIG. 7, in the particle size measuring device D, the control unit 31 of the control processing unit 3 acquires an image using the imaging unit 1 and stores it in the storage unit 7 (S1).

Next, in the particle size measuring device D, the shading correction processing section 32 of the control processing section 3 performs shading correction on the image acquired from the imaging section 1 in process S1 to generate a shading corrected image, and stores it in the storage section 7. (S2).

Subsequently, in the particle size measuring device D, the smoothing processing unit 33 of the control processing unit 3 smoothes the shading corrected image generated by the shading correction processing unit 32 in process S2 to generate a second smoothed image, and stores the smoothed image. The information is stored in the unit 7 (S3).

Next, in the particle size measuring device D, the binarization processing unit 34 of the control processing unit 3 binarizes the second smoothed image generated by the smoothing processing unit 33 in process S3 to generate a binarized image. and stores it in the storage unit 7 (S4).

Subsequently, in the particle size measuring device D, the separation processing section 35 of the control processing section 3 converts the binarized image generated by the binarization processing section 34 in process S4 into the above-mentioned image formed by connecting a plurality of spherical shapes. A separation process is performed to separate the bright area into spherical bright areas, and a binarized image after the separation process is generated and stored in the storage unit 7 (S5).

Next, the particle size measuring device D assigns a serial number starting from 1 to each of the separated bright areas in the binarized image after the separation processing unit subjected to the separation processing in processing S5 by the separation processing unit 35 of the control processing unit 3. (S6).

Next, the particle size measuring device D uses the expansion processing unit 36 of the control processing unit 3 to select one bright region from each bright region in the binarized image after separation processing generated by the separation processing unit 35 in processing S5. A bright region is selected, an expansion process is performed on the selected bright area, and a binarized image after the expansion process of the selected bright area is stored in the storage unit 7 (S7). At this time, the expansion processing unit 36 associates the selected bright region with the fact that it has been selected. For example, a flag indicating whether or not it has been selected (selection status flag; "1" indicates selected, "0" indicates unselected) is associated with the serial number of the selected bright area.

Next, in the particle size measuring device D, the ellipse approximation processing unit 37 of the control processing unit 3 performs ellipse approximation processing on the bright region selected in the process S7 to transform its shape into the most approximate ellipse shape. Then, the binarized image obtained by subjecting the selected bright region to ellipse approximation processing is stored in the storage unit 7 (S8).

Next, in the particle size measuring device D, the extraction processing unit 38 of the control processing unit 3 determines whether or not the bright region selected in the process S7 satisfies the determination condition, and determines whether or not the bright region that satisfies the determination condition is Extraction processing for extracting a region is performed (S9). More specifically, as described above, the extraction processing unit 38 determines the diameter R in the selected bright region, determines the circularity TC and the circularity CD, and satisfies the determination condition for the selected bright region. Determine whether the following is satisfied. As a result of this determination, if Thd<R<Thu, TC>Th, and CD>Th2, the extraction processing unit 38 determines that the selected bright region is a particle, and The bright region is extracted as the spherical object and stored together with its particle size R. For example, a flag indicating whether or not it is recognized as a particle (particle recognition flag, "1" represents a particle recognition, "0" represents a particle non-recognition) is attached to the serial number of the selected bright area along with its particle size R. Associated with a number. On the other hand, if at least one of Thd<R<Thu, TC>Th, and CD>Th2 does not hold as a result of the determination, the extraction processing unit 38 determines that the selected bright region is not a particle. The selected bright region is not extracted as the spherical object.

Subsequently, in the particle size measuring device D, the extraction processing unit 38 finishes each of the processes S7 to S9 for all bright areas, that is, all the bright areas assigned serial numbers in process S6. It is determined whether or not (S10). As a result of this determination, if each process has been completed for all bright areas (YES), the particle size measuring device D next executes process S11. On the other hand, if the result of the determination is that each process has not been completed for all bright areas (NO), the particle size measuring device D returns the process to process S7. Therefore, each of these processes S7 to S9 is performed for all the bright areas assigned serial numbers in process S6. For example, in the selection of bright areas in the process S7, the bright areas are selected sequentially in the order of serial numbers, and for each bright area assigned a serial number in the process S6, these processes S7 to S7 are sequentially selected in the order of the serial numbers. Each process of process S9 is performed.

In this process S11, the particle size measuring device D uses the control unit 31 to set the diameter R of the bright region extracted by the extraction processing unit 38 as the particle size of the object corresponding to the bright region extracted by the extraction processing unit 38. It is output from the output unit 5, and this process ends. In this output, for example, the particle size is divided into a plurality of classes, each of the plurality of classes is assigned a different display mode, and the binarized image after dilation processing and ellipse approximation processing is divided into each bright region. is displayed on the output section 5 in a display mode corresponding to the class to which the particle size R of the bright region belongs. For example, the particle size is divided into a first class with a particle size of 2 mm or less, a second class with a particle size of more than 2 mm and less than 2.8 mm, and a third class with a particle size of more than 2.8 mm. The color red is assigned to the second class, the color green is assigned as the display mode, and the color yellow is assigned the display mode to the third class.

Note that, if necessary, the measurement results of the particle size may be output from the IF section 6 to an external device.

By operating in this way, the particle size measuring device D determines the particle size of particles recognized as particles based on images of a plurality of deposited spherical objects captured by the imaging unit 1.

Here, in FIG. 7, the particle size measuring device D performs shading correction processing, smoothing processing, binarization processing, separation processing, dilation processing, ellipse approximation processing, and extraction processing when measuring particle diameter. The shading correction process, the smoothing process, the separation process, the dilation process, and the ellipse approximation process are more preferably processes for measuring the particle size, and do not necessarily need to be performed. Some or all of the labor may be saved. That is, the particle size measuring device D basically includes an imaging section 1, a binarization processing section 34 that performs the binarization processing, an extraction processing section 38 that performs the extraction processing, and an output section 5. Often, some or all of the shading correction processing, the smoothing processing, the separation processing, the expansion processing, and the ellipse approximation processing are added to the particle size measuring device D in this basic form as necessary. Ru.

FIG. 8 shows an example of the results obtained by the particle size measuring device D of the basic form. That is, in FIG. 8, an image is acquired by the imaging unit 1, the acquired image is binarized to generate a binarized image, and a serial number is attached to each bright area of the binarized image. The results of extraction processing performed on each bright region of the binarized image are shown as an example. FIG. 8A shows an image acquired by the imaging unit 1, and FIG. 8B shows an image resulting from extraction processing on the image shown in FIG. 8A. As can be seen from a comparison between the image shown in FIG. 8A and the image shown in FIG. 8B, of the plurality of deposited spherical objects, the object exposed in the top layer is preferentially extracted. Although not shown, the particle size of the object determined by the sieve and the particle size of the object determined by the particle size measuring device D as described above have a correlation coefficient R ² =0 in this specific example. The correlation was .7957.

FIG. 9 shows an example of the result when the expansion process is added to the basic particle size measuring device D. That is, in FIG. 9, an image is acquired by the imaging unit 1, the acquired image is binarized to generate a binarized image, and a serial number is attached to each bright area of this binarized image. The results are shown as an example when extraction processing is performed on each bright region of the binarized image after expansion processing is performed. FIG. 9A shows an image acquired by the imaging unit 1, and FIG. 9B shows an image resulting from extraction processing on the image shown in FIG. 9A. As can be seen by comparing the image shown in FIG. 9A and the image shown in FIG. 9B, of the plurality of deposited spherical objects, the object exposed in the top layer is preferentially extracted. Although not shown, the particle size of the object determined by the sieve and the particle size of the object determined by the particle size measuring device D as described above have a correlation coefficient R ² =0 in this specific example. It was more correlated at .8037. It can be inferred that this is because the particles, which appeared smaller in the image due to the illumination due to the expansion process, became closer to their actual size due to the expansion process.

FIG. 10 shows an example of the result when the expansion process and the ellipse approximation process are added to the basic particle size measuring device D. That is, in FIG. 10, an image is acquired by the imaging unit 1, the acquired image is binarized to generate a binarized image, and a serial number is attached to each bright area of the binarized image. The results are shown as an example when extraction processing is performed after each of the expansion processing and ellipse approximation processing is performed on each bright region of the binarized image. FIG. 10A shows an image acquired by the imaging unit 1, and FIG. 10B shows an image resulting from extraction processing on the image shown in FIG. 10A. Although FIGS. 8B and 9B show binarized images, FIG. 10B shows a grayscale image because connected particles and overlapping particles become difficult to see when shown in a binarized image. It is shown. As can be seen from a comparison between the image shown in FIG. 10A and the image shown in FIG. 10B, of the plurality of deposited spherical objects, the object exposed in the top layer is preferentially extracted. Although not shown, the particle size of the object determined by the sieve and the particle size of the object determined by the particle size measuring device D as described above have a correlation coefficient R ² =0 in this specific example. The correlation was even higher at .8103. If the number of measurements is further increased in this specific example, as shown in FIG. The particle size of the object (horizontal axis) was correlated with a correlation coefficient R ² =0.8664. The average particle size in FIG. 11 is the average value of the particle sizes of all particles.

FIG. 12 shows an example of the results of measuring a plurality of stacked green pellets Ob, which are conveyed on the conveyor BC during granulation, using the particle size measuring device D in the embodiment. ing. FIG. 12A shows the actual measurement results of the average particle diameter during granulation, FIG. 12B shows each image at time t1 shown in FIG. 12A and its extraction results, and FIG. 12C shows each image at time t2 shown in FIG. 12A. FIG. 12D shows each image at time t3 shown in FIG. 12A and its extraction results. In FIGS. 12B to 12D, the image generated by the imaging unit 1 is shown in the upper part, and the extraction result is shown in the lower part. The measurement result #1 shown in FIG. 12A is the measurement result in the first region from the left side of the paper in plan view shown in FIGS. 12B to 12D, and the measurement result #2 shown in FIG. These are the measurement results for the second region from the left side of the paper in the plan view shown in each of FIGS. 12D, and the measurement results of #3 shown in FIG. The measurement result #4 shown in FIG. 12A is the measurement result in the fourth region from the left side of the paper in the plan view shown in FIGS. 12B to 12D, respectively.

As can be seen from FIG. 12A, at time t2, the average particle size of the measurement results in the fourth region from the left side of the paper in plan view is larger than in the other regions. Referring to the image shown in the upper part of FIG. 12C, it can be confirmed that the particles in the fourth region are larger than the other regions (the first to third regions). Therefore, the particle size measuring device D in this embodiment is capable of quantitatively and continuously measuring the particle size.

As explained above, the particle size measuring device D in the embodiment, and the particle size measuring method and particle size measuring program implemented therein are based on images taken of a plurality of deposited spherical objects. Since the particle size of the object is measured, there is no need to take out the object as in the sieve test. The particle size measuring device D, the particle size measuring method, and the particle size measuring program are such that the diameter of the bright region based on area is within a predetermined range, and the circularity of the bright region is less than a predetermined first threshold value. Since the bright area is large and the circularity of the bright area is larger than a predetermined second threshold value, when a plurality of objects are piled up, only the object exposed at the top can be recognized. Particle size can be measured.

The above particle size measuring device D, particle size measuring method, and particle size measuring program use illumination, so particle sizes can be measured under a constant lighting environment. Since sufficient illuminance is ensured even under certain conditions, it is possible to generate clear images by reducing the exposure time during imaging (i.e. by increasing the shutter speed), which reduces variations in measurement accuracy. can be reduced.

Since the particle size measuring device D, the particle size measuring method, and the particle size measuring program perform shading correction processing, even when there is spatial unevenness in illuminance, the unevenness in illuminance can be reduced and the particle size can be measured with higher accuracy.

Since the particle size measuring device D, the particle size measuring method, and the particle size measuring program perform smoothing processing, differences in brightness caused by the shape of the object surface, deposits, etc. can be reduced, and particle sizes can be measured with higher accuracy.

Since the particle size measuring device D, the particle size measuring method, and the particle size measuring program perform separation processing, even if a plurality of spherical shapes are connected, they can be separated, and the particle size can be measured with higher accuracy.

The above particle size measuring device D, particle size measuring method, and particle size measuring program perform expansion processing, so if the outer periphery of the object is reflected darkly, the measurement will be smaller than the actual size. However, since the outer periphery of the bright region is expanded, the particle size can be measured closer to the actual size.

Since the particle size measuring device D, the particle size measuring method, and the particle size measuring program perform ellipse approximation processing, it is difficult to see the shape of a plurality of accumulated spherical objects because they overlap slightly. , the shape can be restored by ellipse approximation, and the number of measurable objects can be increased.

In the above-described embodiment, the particle size measuring device D is equipped with the imaging unit 1 that generates an image of the raw pellet Ob in order to measure the particle size of the iron ore pellet in substantially real time. In order to verify the process, instead of or in addition to the imaging unit 1, the particle size measuring device D includes an image acquisition unit that acquires images of a plurality of deposited spherical objects. may be provided. Such a particle size measuring device D basically includes the image acquisition section, a binarization processing section, an extraction processing section, and an output section. These binarization processing section, extraction processing section, and output section are the same as the above-mentioned binarization processing section 34, extraction processing section 38, and output section 5, respectively.

The image acquisition unit is an interface circuit that inputs and outputs data to and from external equipment. The external device is a storage medium, such as a USB (Universal Serial Bus) memory and an SD card (registered trademark), which stores images of a plurality of deposited spherical objects. Alternatively, the external device may be a CD-ROM (Compact Disc Read Only Memory), a CD-R (Compact Disc Recordable), or a DVD-ROM (Digital Versatile Disc Read Only Memory) on which the image is recorded. y Memory) and DVD-R This is a drive device that reads data from a recording medium such as a (Digital Versatile Disc Recordable). This interface circuit as an image acquisition unit may be connected to the external device by wire or wirelessly. Alternatively, the image acquisition unit is, for example, a communication interface circuit that transmits and receives communication signals to and from an external device, and the external device is connected to a network (WAN (Wide Area Network, including public communication network)) or LAN ( The server device is connected to the communication interface circuit via a local area network (Local Area Network) and manages the images. Such an image acquisition section may also be used as the IF section 6 (that is, the IF section 6 may be used as the image acquisition section).

In order to express the present invention, the present invention has been adequately and fully described through embodiments with reference to the drawings in the above description, but those skilled in the art will easily be able to modify and/or improve the embodiments described above. It should be recognized that this is possible. Therefore, unless the modification or improvement made by a person skilled in the art does not depart from the scope of the claims stated in the claims, such modifications or improvements do not fall outside the scope of the claims. It is interpreted as encompassing.

D Particle size measuring device 1 Imaging section 2 Illumination section 3 Control processing section 4 Input section 5 Output section 6 Interface section (IF section)
7 Storage section 31 Control section 32 Shading correction processing section 33 Smoothing processing section 34 Binarization processing section 35 Separation processing section 36 Dilation processing section 37 Ellipse approximation processing section 38 Extraction processing section

Claims (11)

an imaging unit that generates an image by imaging a plurality of deposited spherical objects;
a binarization processing unit that binarizes the image generated by the imaging unit based on the luminance value to generate a binarized image;
Among one or more bright regions in the binarized image generated by the binarization processing unit, the diameter of the bright region based on the area is within a predetermined range, and the circularity of the bright region is larger than a predetermined first threshold, and the bright region has a circularity larger than a predetermined second threshold;
an output unit that outputs the diameter of the bright region extracted by the extraction processing unit as a particle size of an object corresponding to the bright region extracted by the extraction processing unit,
The roundness is the reciprocal of the aspect ratio, which is the ratio of the long axis length to the short axis length when the outline of the bright region is approximated as an ellipse,
The degree of circularity is the result of dividing the area of the bright region by the square of the perimeter of the bright region, multiplied by four times the circumference,
Particle size measuring device. further comprising an illumination unit that illuminates the plurality of objects;
The particle size measuring device according to claim 1. further comprising a shading correction processing unit that performs shading correction on the image generated by the imaging unit before binarization by the binarization processing unit;
The particle size measuring device according to claim 1 or claim 2. Further comprising a smoothing processing unit that smoothes the image generated by the imaging unit before the binarization processing unit binarizes the image.
The particle size measuring device according to claim 1 or claim 2. Further comprising a separation processing unit that separates the bright region formed by connecting a plurality of spherical shapes into spherical bright regions before extraction by the extraction processing unit.
The particle size measuring device according to any one of claims 1 to 4. Further comprising an expansion processing unit that performs expansion processing to expand the outer periphery of the bright region by a predetermined length outward in the radial direction one or more times before extraction by the extraction processing unit;
The particle size measuring device according to any one of claims 1 to 4. further comprising an ellipse approximation processing unit that transforms the shape of the bright region into the most approximate elliptical shape before extraction by the extraction processing unit;
The particle size measuring device according to any one of claims 1 to 4. an image acquisition unit that acquires an image of a plurality of deposited spherical objects;
a binarization processing unit that binarizes the image acquired by the image acquisition unit based on the luminance value to generate a binarized image;
Among one or more bright regions in the binarized image generated by the binarization processing unit, the diameter of the bright region based on the area is within a predetermined range, and the circularity of the bright region is larger than a predetermined first threshold, and the bright region has a circularity larger than a predetermined second threshold;
an output unit that outputs the diameter of the bright region extracted by the extraction processing unit as a particle size of an object corresponding to the bright region extracted by the extraction processing unit,
The roundness is the reciprocal of the aspect ratio, which is the ratio of the long axis length to the short axis length when the outline of the bright region is approximated as an ellipse,
The degree of circularity is the result of dividing the area of the bright region by the square of the perimeter of the bright region, multiplied by four times the circumference,
Particle size measuring device. an imaging step of generating an image by imaging a plurality of deposited spherical objects;
a binarization processing step of binarizing the image generated in the imaging step based on the luminance value to generate a binarized image;
Among one or more bright regions in the binarized image generated in the binarization processing step, the diameter of the bright region based on area is within a predetermined range, and the roundness of the bright region is larger than a predetermined first threshold, and the bright region has a circularity larger than a predetermined second threshold;
an output step of outputting the diameter of the bright region extracted in the extraction processing step as a particle size of an object corresponding to the bright region extracted in the extraction processing step,
The roundness is the reciprocal of the aspect ratio, which is the ratio of the long axis length to the short axis length when the outline of the bright region is approximated as an ellipse,
The degree of circularity is the result of dividing the area of the bright region by the square of the perimeter of the bright region, multiplied by four times the circumference,
Particle size measurement method. an image acquisition step of acquiring an image of a plurality of deposited spherical objects;
a binarization processing step of binarizing the image obtained in the image acquisition step based on the luminance value to generate a binarized image;
Among one or more bright regions in the binarized image generated in the binarization processing step, the diameter of the bright region based on area is within a predetermined range, and the roundness of the bright region is larger than a predetermined first threshold, and the bright region has a circularity larger than a predetermined second threshold;
an output step of outputting the diameter of the bright region extracted in the extraction processing step as a particle size of an object corresponding to the bright region extracted in the extraction processing step,
The roundness is the reciprocal of the aspect ratio, which is the ratio of the long axis length to the short axis length when the outline of the bright region is approximated as an ellipse,
The degree of circularity is the result of dividing the area of the bright region by the square of the perimeter of the bright region, multiplied by four times the circumference,
A computer-implemented particle size measurement method. an image acquisition step of acquiring an image of a plurality of deposited spherical objects;
a binarization processing step of binarizing the image obtained in the image acquisition step based on the luminance value to generate a binarized image;
Among one or more bright regions in the binarized image generated in the binarization processing step, the diameter of the bright region based on area is within a predetermined range, and the roundness of the bright region is larger than a predetermined first threshold, and the bright region has a circularity larger than a predetermined second threshold;
an output step of outputting the diameter of the bright region extracted in the extraction processing step as a particle size of an object corresponding to the bright region extracted in the extraction processing step,
The roundness is the reciprocal of the aspect ratio, which is the ratio of the long axis length to the short axis length when the outline of the bright region is approximated as an ellipse,
The degree of circularity is the result of dividing the area of the bright region by the square of the perimeter of the bright region, multiplied by four times the circumference,
Particle size measurement program run by computer.

Images