JP7571582B2 - PARTICLE IMAGE ANALYSIS APPARATUS, PARTICLE IMAGE ANALYSIS METHOD, AND PARTICLE IMAGE ANALYSIS PROGRAM - Google Patents

Description

The present invention relates to a particle image analysis device, a particle image analysis method, and a particle image analysis program.

Various techniques are known for extracting particle images in particle image analysis devices. In particle image analysis devices, a liquid sample containing dispersed particles is caused to flow through a flow path at a predetermined speed, and the liquid sample is photographed at a predetermined interval to obtain a sample image, which is then analyzed.

For example, in the particle image analysis device described in Patent Document 1, the particle image identification processing unit identifies the image of a particle contained in the sample image by comparing the brightness of each pixel of the sample image with a predetermined value. In addition, the surrounding image extraction processing unit extracts a surrounding image of the particle, including an image of one particle identified by the particle image identification processing unit, from the sample image. Furthermore, the particle region identification processing unit identifies a particle region in the surrounding image by comparing the brightness of each pixel of the surrounding image extracted by the surrounding image extraction processing unit with a second threshold value. Note that the second threshold value is calculated based on the brightness of the pixel with the lowest or highest brightness among the pixels of the surrounding image and a reference value of the brightness of each pixel in the surrounding image other than the particles.

JP 2019-158352 A

However, in the particle image analysis device described in Patent Document 1, when foreign matter such as contaminant particles adhere to the wall surface of the flow path, the image of the foreign matter may be erroneously recognized as an image of the particle. The contaminant particles are particles different from the particles to be analyzed and are mixed into the liquid sample.
Furthermore, if foreign matter such as contaminant particles adhere to the wall surface of the flow path during the period in which the sample image is captured, a sample image that does not include an image of the foreign matter and a sample image that includes an image of the foreign matter are generated, making it even more difficult to distinguish between the image of the foreign matter and the image of the particle.

The present invention aims to provide a particle image analysis device, a particle image analysis method, and a particle image analysis program that can prevent images of foreign matter, such as contaminant particles attached to a flow path, from being mistakenly recognized as images of particles.

The particle image analysis device according to the first aspect of the present invention is a particle image analysis device that analyzes images of particles contained in a sample image obtained by flowing a liquid sample in which particles are dispersed through a flow path at a predetermined speed and photographing the liquid sample at a predetermined cycle, and includes a generation unit that generates a blank image based on a plurality of the sample images, and a correction unit that corrects the sample image based on the blank image.

The particle image analysis method according to the second aspect of the present invention is a particle image analysis method for a particle image analyzer that analyzes images of particles contained in a sample image obtained by flowing a liquid sample in which particles are dispersed through a flow path at a predetermined speed and photographing the liquid sample at a predetermined cycle, and includes a generating step of generating a blank image based on a plurality of the sample images, and a correcting step of correcting the sample image based on the blank image.

The particle image analysis program according to the third aspect of the present invention is a particle image analysis program that analyzes images of particles contained in a sample image obtained by flowing a liquid sample having particles dispersed therein through a flow path at a predetermined speed and photographing the liquid sample at a predetermined cycle, and causes a computer to function as a generating unit that generates a blank image based on a plurality of the sample images, and a correcting unit that corrects the sample image based on the blank image.

The particle image analysis device according to the first aspect of the present invention, the particle image analysis method according to the second aspect of the present invention, and the particle image analysis program according to the third aspect of the present invention generate blank images based on a plurality of sample images, and correct the sample images based on the blank images, thereby preventing an image of a foreign object attached to a flow path from being mistakenly recognized as an image of a particle.

1 is a diagram illustrating an example of a configuration of a particle image analyzer according to an embodiment of the present invention. FIG. 13 is a diagram showing an example of a blank image when no foreign matter is mixed in; FIG. 13 is a diagram showing an example of a blank image when a foreign object is mixed in; FIG. 13 is a diagram showing an example of a corrected image when correction is performed using a conventional blank image. FIG. 13 is a diagram showing an example of a corrected image when corrected with a blank image of the present invention. FIG. 13 is a diagram showing an example of a corrected image obtained by correcting a sample image before contaminant particles adhere to it with a blank image after contaminant particles adhere to it. FIG. 13 is a diagram showing an example of a corrected image obtained by correcting a sample image after contamination particles have adhered thereto using a blank image before contamination particles have adhered thereto. FIG. 13 is a diagram showing an example of a corrected image obtained by correcting a sample image after contamination particles have adhered thereto with a blank image after contamination particles have adhered thereto. 10 is a flowchart illustrating an example of a process of a control unit. 10 is a flowchart showing an example of a fixed particle detection process by a control unit.

This embodiment will be described below with reference to the drawings.

[1. Configuration of particle image analyzer]
FIG. 1 is a diagram showing an example of the configuration of a particle image analyzer 1 according to the present embodiment.
The particle image analyzer 1 analyzes images of the particles PT of the powder sample SP contained in a sample image PS obtained by flowing a liquid sample SL, in which particles PT of a powder sample SP are dispersed, through a flow path at a predetermined speed VA and photographing the liquid sample SL at a predetermined period TA. The particle image analyzer 1 also analyzes the particle properties of the particles PT of the powder sample SP based on the results of the image analysis.

The powder sample SP is, for example, a powder of an industrial product such as a pigment, a cosmetic powder, a toner, a particulate catalyst, an abrasive, a powdered medicine, a synthetic resin powder, fine ceramic particles, a metal particle, etc. The particle property is typically a particle shape, and includes a circle equivalent diameter, a circularity, an aspect ratio, etc.
The particle image analyzer 1 analyzes images of particles PT of a powder sample SP by the dynamic image analysis method defined in JIS Z8827-2.
The size of the particles PT of the powder sample SP is, for example, 5 μm to 100 μm.

As shown in FIG. 1, the particle image analyzer 1 includes a flow cell 2 , a liquid sample supplying mechanism 4 , an illumination unit 6 , a camera 8 , a focus mechanism 10 , and a control unit 12 .
The flow cell 2 is an optically nearly transparent measurement container formed in a nearly rectangular plate shape. An inlet 14A for introducing a liquid sample SL is formed on an upper end surface 2A of the flow cell 2, and an outlet 14B for discharging the liquid sample SL is formed on a lower end surface 2B of the flow cell 2. A flow path 16 is formed linearly from the inlet 14A to the outlet 14B.
The flow cell 2 of this embodiment is provided with a focus target (not shown) for focusing, and the control unit 12 is configured to adjust the focus of the camera 8 based on the focus target.

The liquid sample supply mechanism 4 is a mechanism for feeding a predetermined amount of the liquid sample SL into the flow cell 2 per unit time, and includes a liquid feed pump 22. In other words, the liquid feed pump 22 causes the liquid sample SL to flow through the flow channel 16 at a predetermined speed VA. The predetermined speed VA is, for example, 14.5 mm/sec.
In this embodiment, an inlet pipe 26 extending from a liquid sample storage container 24 that stores a liquid sample SL is connected to the inlet 14A of the flow cell 2. One end of a discharge pipe 28 is connected to the outlet 14B, and the other end of the discharge pipe 28 is connected to the suction side of the liquid delivery pump 22.
By operating the liquid feed pump 22, the liquid sample SL in the liquid sample storage container 24 flows from the inlet 14A into the flow path 16 of the flow cell 2, passes through the flow path 16, and is discharged from the outlet 14B.
A waste liquid pipe 30 is connected to the discharge side of the liquid delivery pump 22, and the liquid sample discharged by the liquid delivery pump 22 is collected in a waste liquid tank 32 through the waste liquid pipe 30. The liquid delivery pump 22 may be provided on the side of the introduction pipe 26.

The illumination unit 6 includes a light source device 6A that irradiates the flow cell 2 with measurement light 34. The light source device 6A of this embodiment irradiates the measurement light 34, which is substantially parallel light, from a direction substantially perpendicular to the flow path 16 of the flow cell 2. The light source device 6A includes a light source having a light-emitting element such as an LED (Light Emitting Diode) light source or a laser light source, and a collimating optical system that converts the light emitted by the light source into parallel light. The light source device 6A may include a planar light source that emits light in a planar manner, such as a COB (Chip On Board) type LED, as the light source.

The camera 8 is disposed at a position facing the illumination unit 6 across the flow cell 2, and captures the irradiated portion of the flow cell 2 with the measurement light 34 at a predetermined period TA in accordance with instructions from the control unit 12. The camera 8 of this embodiment includes an image sensor 36 and a telecentric microscope 38. The image sensor 36 is composed of a CCD (Charge Coupled Device) or a CMOS (Complementary Metal Oxide Semiconductor), etc. The telecentric microscope 38 is a telecentric optical system that forms an image of the irradiated portion of the flow cell 2 on the image plane 36A of the image sensor 36, and includes a telecentric lens 40 disposed opposite the flow cell 2.

The shooting speed of the camera 8 is, for example, 8 FPS. That is, the predetermined period TA is 0.125 seconds. The predetermined period TA is set so as to satisfy the following condition.
That is, the predetermined speed VA and the predetermined period TA are each set so that the particles flowing inside the flow channel 16 are not included in two successively captured images of the sample PS.
In other words, the predetermined speed VA and the predetermined period TA are set so as to satisfy the following formula (1).
VA>LA/TA (1)
Here, the length LA indicates the length of the particle PT in the flow direction in the field of view of the camera 8. For example, the length LA is 1.8 mm. In this case, the value of the right side of the formula (1) is 14.4 (= 1.8/0.125) mm/sec, which satisfies the formula (1) when the predetermined speed VA is 14.5 mm/sec.

In this way, the predetermined speed VA and the predetermined period TA are each set so that the particle PT flowing through the flow path 16 is not included in two consecutively captured sample images PS, thereby preventing the image of the same particle PT from being captured multiple times.

The focus mechanism 10 is a mechanism for varying the focus of the telecentric microscope 38, and includes a lens driving mechanism 42. The lens driving mechanism 42 is a mechanism for varying the focus of the camera 8 by driving the telecentric lens 40 along the optical axis A of the telecentric optical system under the control of the control unit 12.

[2. Configuration of the control unit]
The control unit 12 is configured, for example, by a personal computer, and controls the operation of the particle image analyzer 1 .
The control unit 12 includes a processor 51, a memory 52, a storage device such as a hard disk drive (HDD) or a solid state drive (SSD), and an interface circuit for connecting the camera 8 and the like.
The processor 51 is composed of a CPU (Central Processing Unit), an MPU (Micro-Processing Unit), and the like.
The memory 52 is composed of a ROM (Read Only Memory), a RAM (Random Access Memory), or the like.
The control unit 12 corresponds to an example of a "computer."

The control unit 12 is not limited to a personal computer, and may be configured by one or more appropriate circuits such as integrated circuits such as IC chips and LSIs. The control unit 12 may also be configured by, for example, a tablet terminal, a smartphone, or the like.
The control unit 12 may also include programmed hardware such as a digital signal processor (DSP) or a field programmable gate array (FPGA), or may also include a system-on-a-chip (SoC)-FPGA.

1, the control unit 12 includes an imaging control unit 511, a detection unit 512, a classification unit 513, an extraction unit 514, a generation unit 515, a correction unit 516, and an image storage unit 521. Specifically, the processor 51 of the control unit 12 executes a control program PG stored in the memory 52 to function as the imaging control unit 511, the detection unit 512, the classification unit 513, the extraction unit 514, the generation unit 515, and the correction unit 516. The processor 51 of the control unit 12 also executes the control program PG stored in the memory 52 to cause the memory 52 to function as the image storage unit 521.
The control program PG corresponds to an example of a "particle image analysis program".

The image storage unit 521 stores the sample images PS obtained by photographing the liquid sample SL with the camera 8 at a predetermined period TA.
In addition, the image storage unit 521 stores the blank image BL generated by the generation unit 515 .
Moreover, the image storage unit 521 stores the corrected image PC generated by the correction unit 516 .

The imaging control unit 511 adjusts the autofocus of the camera 8 and adjusts the timing of image capture by the camera 8 .
The imaging control unit 511 adjusts the focus of the camera 8 (telecentric microscope 38) based on the captured image of the focus target of the flow cell 2. Specifically, the imaging control unit 511 captures the captured image of the camera 8, and determines the deviation between the focus of the camera 8 and the focus target based on the captured state of the focus target shown in the captured image. Then, the imaging control unit 511 controls the lens driving mechanism 42 so that the telecentric lens 40 moves to a position that eliminates the deviation of the focus. In this way, the imaging control unit 511 can adjust the focus of the camera 8 to the focus target.
The imaging control unit 511 also causes the camera 8 to capture an image of the liquid sample SL at a predetermined period TA and generate a sample image PS. The imaging control unit 511 also records the generated sample image PS in the image storage unit 521.

The detection unit 512 detects fixed particles FP that do not flow through the flow path 16. The fixed particles FP are, for example, foreign matter such as contaminant particles attached to the wall surface of the flow cell 2 on the side of the flow path 16. Note that the "contaminant particles" refer to particles that are different from the particles PT to be analyzed and that are mixed into the liquid sample SL.
The detection unit 512 detects a fixed particle FP when the brightness values of multiple pixels that are arranged at corresponding positions and adjacent to each other in a predetermined number of sample images PS that are two or more sheets of sample images that have been captured consecutively are equal to or less than a first threshold value.
The first threshold corresponds to an example of a "predetermined value."

As will be described later with reference to Figures 2 and 3, the size of the flow path 16 is sufficiently larger than the size of the particles PT of the powder sample SP. For example, the size of the flow path 16 is 10 times or more the maximum size of the particles PT of the powder sample SP. Furthermore, the particles PT of the powder sample SP are dispersed in the liquid sample SL so that the sample image PS includes images of, for example, one to three particles PT of the powder sample SP. Therefore, the probability that images of the particles PT of the powder sample SP are continuously detected at the same position in the sample image PS is extremely low.
Therefore, in a predetermined number of samples PS (two or more) captured in succession, when the luminance values of a plurality of pixels that are arranged at corresponding positions and adjacent to each other are equal to or less than the first threshold value, the fixed particles FP can be detected.

The larger the predetermined number, the more accurately the fixed particles FP can be detected by the detection unit 512. The smaller the predetermined number, the more simply the processing by the detection unit 512. The predetermined number is, for example, five.
The number of pixels in the adjacent pixels is set according to the number of pixels in the image of the particle PT of the powder sample SP included in the sample image PS. The number of pixels in the adjacent pixels is set to be smaller than the number of pixels in the image of the smallest particle PT, for example. The number of pixels in the adjacent pixels is set to be ¼ of the number of pixels in the image of the smallest particle PT, for example.
The greater the number of pixels in the plurality of pixels, the more simplified the processing of the detection unit 512. The smaller the number of pixels in the plurality of pixels, the smaller the fixed particles FP that can be detected.
The first threshold value is set according to the brightness value of the image of the particles PT of the powder sample SP included in the sample image PS. The first threshold value is set to be, for example, greater than the maximum brightness value of the image of the particles PT of the powder sample SP included in the sample image PS.
The smaller the first threshold value, the simpler the process of the detection unit 512. The larger the first threshold value, the more accurately the detection unit 512 can detect the fixed particle FP.

The fixed particles FP include first fixed particles FP1 and second fixed particles FP2.
The first fixed particle FP1 indicates a foreign matter such as a contaminant particle adhering to the wall surface of the flow cell 2 on the side of the flow channel 16 at the time when the camera 8 starts capturing the sample image PS.
The second fixed particle FP2 is not attached to the wall surface of the flow cell 2 on the flow path 16 side at the time when the camera 8 starts capturing the sample image PS, and represents foreign matter such as contaminant particles that adhere to the wall surface of the flow cell 2 on the flow path 16 side while the camera 8 is capturing the sample image PS.
The detection unit 512 mainly detects the second fixed particles FP2. This is because the influence of the first fixed particles FP1 can be suppressed by the correction unit 516 correcting the sample image PS based on the blank image BL generated by the generation unit 515.

When the detection unit 512 detects the second fixed particle FP2, the classification unit 513 classifies the sample images PS obtained by photographing the liquid sample SL into a first sample image group PS1 and a second sample image group PS2.
The first sample image group PS1 indicates images captured before the predetermined number of sample images PS at which the detection unit 512 detects the second fixed particle FP2. The second sample image group PS2 indicates images captured after the predetermined number of sample images PS at which the detection unit 512 detects the second fixed particle FP2.
The second sample image group PS2 may include a predetermined number of sample images PS in which the second fixed particles FP2 are detected.

Based on the detection result of the detection unit 512, the extraction unit 514 extracts a plurality of sample images PS from the sample images PS obtained by photographing the liquid sample SL.
Specifically, when the detection unit 512 detects the second fixed particle FP2, the extraction unit 514 extracts a plurality of sample images PS as follows. That is, when the generation unit 515 generates the first blank image BL1, the extraction unit 514 extracts a plurality of sample images PS included in the first sample image group PS1. The first blank image BL1 indicates a blank image BL used to correct the sample images PS included in the first sample image group PS1. Furthermore, when the generation unit 515 generates the second blank image BL2, the extraction unit 514 extracts a plurality of sample images included in the second sample image group PS2. The second blank image BL2 indicates a blank image BL used to correct the sample images PS included in the second sample image group PS2.

The generating unit 515 generates a blank image BL based on the multiple sample images PS. The blank image BL indicates an image used when the correcting unit 516 corrects the sample image PS. The generating unit 515 records the generated blank image BL in the image storage unit 521.
The generating unit 515 generates the blank image BL, for example, by calculating a median value of the luminance values of each pixel of the multiple sample images PS. The generating unit 515 may generate the blank image BL, for example, by calculating an average value of the luminance values of each pixel of the multiple sample images PS. The generating unit 515 may generate the blank image BL, for example, by calculating a mode value of the luminance values of each pixel of the multiple sample images PS.
The blank image BL will be described with reference to FIGS.

Furthermore, when the detection unit 512 detects the second fixed particle FP2, the generation unit 515 generates the first blank image BL1 and the second blank image BL2 as follows. That is, the generation unit 515 generates the first blank image BL1 and the second blank image BL2 based on the multiple sample images PS extracted by the extraction unit 514. Specifically, the generation unit 515 generates the first blank image BL1 by calculating the median value of the brightness values of each pixel of the multiple sample images PS included in the first sample image group PS1. Furthermore, the generation unit 515 generates the second blank image BL2 by calculating the median value of the brightness values of each pixel of the multiple sample images PS included in the second sample image group PS2.
The first blank image BL1 and the second blank image BL2 will be described with reference to FIGS.

The correction unit 516 corrects the sample image PS based on the blank image BL.
Specifically, the correction unit 516 corrects the sample image PS by calculating the difference between the sample image PS and the blank image BL. In the following description, the corrected sample image PS may be referred to as a corrected image PC.
More specifically, the correction unit 516 corrects the sample image PS by calculating the difference between the brightness value BS of each pixel of the sample image PS and the brightness value BB of each pixel of the blank image BL. The brightness value BC of each pixel of the corrected image PC is calculated by the following formula (2).
BC=BS+(BX-BB) (2)
Here, the average brightness value BX indicates the average value of the brightness values BS of the sample image PS.
The corrected image PC will be described with reference to FIG.

Furthermore, when the detection unit 512 detects the second fixed particle FP2, the correction unit 516 corrects the sample image PS by calculating the difference between the sample image PS included in the first sample image group PS1 and the first blank image BL1. In the following description, the corrected sample image PS may be referred to as a first corrected image PC1.
Furthermore, when the detection unit 512 detects the second fixed particle FP2, the correction unit 516 corrects the sample image PS by calculating the difference between the sample image PS included in the second sample image group PS2 and the second blank image BL2. In the following description, the corrected sample image PS may be referred to as a second corrected image PC2.

In this embodiment, the control unit 12 of the particle image analysis device 1 includes an imaging control unit 511, a detection unit 512, a classification unit 513, an extraction unit 514, a generation unit 515, a correction unit 516, and an image storage unit 521, but the embodiment of the present invention is not limited to this. For example, the control unit 12 of the particle image analysis device 1 may include an imaging control unit 511 and an image storage unit 521, and a control device configured as a personal computer or the like separately from the particle image analysis device 1 may include the detection unit 512, the classification unit 513, the extraction unit 514, the generation unit 515, and the correction unit 516.

3. Specific examples of processing by the control unit
Next, a specific example of the process of the control unit 12 will be described with reference to FIGS.
[3-1. Specific examples of processing by the generation unit and the detection unit]
First, a specific example of the processing of the generating unit 515 and the detecting unit 512 will be described with reference to FIG. 2 and FIG.
FIG. 2 is a diagram showing an example of a blank image BL when no foreign matter is mixed into the flow path 16. As shown in FIG.
The generating unit 515 generates a blank image BL by calculating the median value of the luminance values of each pixel of a plurality of sample images PS.
2 indicate a plurality of sample images PS. The integer N indicates the number of the plurality of sample images PS. In other words, the integer N indicates the number of sample images PS used to generate the blank image BL.
The integer N is preferably 5 or greater.
When the generating unit 515 generates the blank image BL by calculating the average brightness value of each pixel of a plurality of sample images PS, the integer N is preferably equal to or greater than "50."

The sample image P11 includes an image showing the flow path 16, and particle images Q1 to Q3 showing particles PT of the powder sample SP.
The sample image P12 includes an image showing the flow path 16, and a particle image Q4 and a particle image Q5 showing particles PT of the powder sample SP.
The sample image P1N includes an image showing the flow path 16, and a particle image Q6 and a particle image Q7 showing particles PT of the powder sample SP.

1, the predetermined velocity VA and the predetermined period TA are set so that particles flowing through the flow path 16 are not included in two consecutively captured images of the sample PS. Thus, particle images Q1 to Q7 show different particles.
Furthermore, as shown in FIG. 2, the size of the flow channel 16 is sufficiently large compared to the sizes of the particle images Q1 to Q7.
Furthermore, the particles PT of the powder sample SP are dispersed in the liquid sample SL so that the sample image PS includes images of, for example, one to three particles PT of the powder sample SP.
Therefore, particle images Q1 to Q7 are disposed at different positions in flow channel 16.

The lower part of FIG. 2 shows a blank image P1A generated by the generating unit 515 by calculating the median value of the luminance values of each pixel of the sample images P11 to P1N.
The blank image P1A does not include any image showing particles PT of the powder sample SP or foreign matter. In other words, the brightness value B of each pixel inside the flow path 16 in the blank image P1A is approximately the average brightness value BX.
In the blank image P1A, when the luminance value B is the average luminance value BX, the luminance value BC of each pixel of the corrected image PC calculated by the formula (2) explained with reference to Fig. 1 matches the luminance value BS of each pixel of the sample image PS. That is, as will be explained later with reference to Fig. 4, the corrected image PC matches the sample image PS.

Furthermore, in the case where the sample images P11 to P1N are sample images PS that have been captured in succession, the detection unit 512 can detect the fixed particle FP based on the sample images P11 to P1N.
The detection unit 512 detects a fixed particle FP when the luminance values of a plurality of pixels that are arranged at corresponding positions and adjacent to each other in the sample images P11 to P1N are equal to or less than a first threshold value.
As described above, no foreign matter is mixed into the flow channel 16, and the particle images Q1 to Q7 are disposed at different positions in the flow channel 16. Therefore, the detection unit 512 does not detect the fixed particle FP.

FIG. 3 is a diagram showing an example of a blank image when a foreign object is mixed into the flow channel 16. As shown in FIG.
3 indicate a plurality of sample images PS. The integer N indicates the number of the plurality of sample images PS. In other words, the integer N indicates the number of sample images PS used to generate the blank image BL.

The sample image P21 includes an image showing the flow path 16, particle images Q1 to Q3 showing particles PT of the powder sample SP, and a foreign matter image FM showing a foreign matter.
The sample image P12 includes an image showing the flow path 16, particle images Q4 and Q5 showing particles PT of the powder sample SP, and a foreign matter image FM showing a foreign matter.
The sample image P1N includes an image showing the flow path 16, particle images Q6 and Q7 showing particles PT of the powder sample SP, and a foreign matter image FM showing a foreign matter.

Similar to FIG. 2, particle images Q1 to Q7 are arranged at different positions in the flow channel 16 in sample images P21 to P2N.
On the other hand, the foreign matter is attached to the wall surface of the flow cell 2 on the side of the flow channel 16, and is therefore located at the same position in the sample images P21 to P2N.

The lower part of FIG. 2 shows a blank image P2A generated by the generation unit 515 by calculating the median value of the luminance values of each pixel of the sample images P21 to P2N.
The blank image P2A does not include any particles PT of the powder sample SP, but includes a foreign matter image FM.

Furthermore, in the case where the sample images P21 to P2N are sample images PS that have been captured in succession, the detection unit 512 can detect the fixed particles FP based on the sample images P21 to P2N.
The detection unit 512 detects a fixed particle FP when the luminance values of a plurality of pixels that are arranged at corresponding positions and adjacent to each other in the sample images P21 to P2N are equal to or less than a first threshold value.
As described above, foreign matter gets mixed into the flow channel 16. Therefore, the detection unit 512 detects the fixed particle FP. The foreign matter image FM shows the fixed particle FP.

[3-2. Specific examples of processing by the correction unit]
Next, a specific example of the process of the correction unit 516 will be described with reference to FIGS.
4 to 8, three images are depicted in the left-right direction. In each of Fig. 4 to 8, the image on the left shows the sample image PS before correction, the image in the middle shows the blank image BL, and the image on the right shows the corrected image PC generated by the correction unit 516.
In each of FIGS. 4 to 8, in order to make the image of the particle PT easier to see, an enlarged image is depicted compared to FIGS. 1 and 2.

First, the difference between a conventional blank image and the blank image BL of the present invention, and the effects of the present invention will be described with reference to FIGS.
FIG. 4 is a diagram showing an example of a corrected image P3B obtained when the sample image P3 is corrected using a conventional blank image P3A.
The blank image P3A is, for example, an image captured by the camera 8 in a state where the liquid sample SL is not flowing through the flow path 16. The blank image P3A does not include a particle image showing a particle PT of the powder sample SP, and a foreign matter image showing a foreign matter.
The sample image P3 includes a particle image Q8 showing a particle PT of the powder sample SP, and a foreign matter image FM showing a foreign matter.
The corrected image P3B includes a particle image Q8 showing a particle PT of the powder sample SP, and a foreign matter image FM showing a foreign matter.

As such, conventionally, the corrected image P3B contained the foreign matter image FM, which could lead to the image of the foreign matter being mistaken for an image of a particle.

FIG. 5 is a diagram showing an example of a corrected image P4B obtained when the sample image P4 is corrected using the blank image P4A of the present invention.
The blank image P4A indicates a blank image BL generated by calculating a median value of the luminance values of each pixel of the multiple sample images PS by the generation unit 515. As described with reference to FIG. 3, the blank image P4A does not include a particle image showing a particle PT of the powder sample SP, but includes a foreign matter image FM showing a foreign matter.
The sample image P4 includes a particle image Q8 showing a particle PT of the powder sample SP, and a foreign matter image FM showing a foreign matter.
The corrected image P4B includes a particle image Q8 showing a particle PT of the powder sample SP, but does not include a foreign matter image FM showing a foreign matter.

In this way, in the present invention, the generation unit 515 generates the blank image BL by calculating the median brightness value of each pixel of the multiple sample images PS, so that when the sample image P4 includes a foreign matter image FM, the correction unit 516 can generate a corrected image P4B that does not include the foreign matter image FM. Therefore, it is possible to prevent foreign matter adhering to the flow path 16 from being erroneously recognized as a particle PT.

Next, an example of a process when the second fixed particle FP2 is detected will be described with reference to FIGS.
6 and 7 are diagrams for explaining the necessity of the classification unit 513 and the extraction unit 514 of this embodiment, and are not diagrams illustrating this embodiment.
As explained with reference to Figure 1, when the second fixed particle FP2 is detected, the sample images PS included in the first sample image group PS1 need to be corrected with the first blank image BL1, and the sample images PS included in the second sample image group PS2 need to be corrected with the second blank image BL2.
In contrast, Figure 6 shows an example of correcting a sample image PS included in the first sample image group PS1 with a second blank image BL2, and Figure 7 shows an example of correcting a sample image PS included in the second sample image group PS2 with a first blank image BL1.

FIG. 6 is a diagram showing an example of a corrected image P5B obtained by correcting a sample image P5 before contamination particles are adhered with a blank image P5A after contamination particles are adhered.
The sample image P5 includes a particle image Q8 showing a particle PT of the powder sample SP, and a foreign matter image FM showing a foreign matter. Here, the foreign matter corresponds to an example of the first fixed particle FP1.
The blank image P5A does not include the particle image Q8, but includes a foreign matter image FM and a contaminant particle image CP. The contaminant particles correspond to an example of the second fixed particles FP2.
The blank image P5A is generated by calculating a median value of the luminance values of each pixel of the multiple sample images PS included in the second sample image group PS2 by the generation unit 515. The blank image P5A corresponds to an example of the second blank image BL2.
The corrected image P5B includes the particle image Q8, but does not include the foreign matter image FM. The particle image Q8 includes a deformed portion CPA in which a part of the particle image Q8 is whitened due to the influence of the contaminant particle image CP.

In this way, if the sample image P5 before the contaminant particles were attached is corrected with the blank image P5A after the contaminant particles were attached, the particle image Q8 in the corrected image P5B includes the deformed portion CPA, and therefore a proper corrected image PC cannot be generated. In other words, the sample image P5 before the contaminant particles were attached needs to be corrected with the blank image BL before the contaminant particles were attached.

In this embodiment, as described with reference to FIG. 1, the sample image P5 before the adhesion of contaminant particles is corrected by the first blank image BL1 to correct the sample image PS. The first blank image BL1 is generated by calculating the median brightness value of each pixel of the multiple sample images PS included in the first sample image group PS1. Therefore, an appropriate corrected image PC can be generated.

FIG. 7 is a diagram showing an example of a corrected image P6B obtained by correcting the sample image P6 after the adhesion of contaminant particles with a blank image P6A before the adhesion of contaminant particles.
The sample image P6 includes a particle image Q9 showing a particle PT of the powder sample SP, a foreign matter image FM showing a foreign matter, and a contaminant particle image CP showing a contaminant particle. Here, the foreign matter corresponds to an example of the first fixed particle FP1. The contaminant particle corresponds to an example of the second fixed particle FP2.
The blank image P6A does not include the particle image Q9 or the contaminant particle image CP, but does include the foreign matter image FM.
The blank image P6A is generated by calculating a median value of the luminance values of each pixel of the multiple sample images PS included in the first sample image group PS1 by the generation unit 515. The blank image P6A corresponds to an example of the first blank image BL1.
The corrected image P6B includes the particle image Q8 and the contaminant particle image CP, but does not include the foreign matter image FM.

In this way, if the sample image P6 after the contaminant particles have adhered is corrected using the blank image P6A before the contaminant particles have adhered, the corrected image P5B contains the contaminant particle image CP, and so a properly corrected image PC cannot be generated. In other words, the sample image P5 after the contaminant particles have adhered needs to be corrected using the blank image BL after the contaminant particles have adhered.

In this embodiment, as described with reference to FIG. 1 and as described with reference to FIG. 8, the sample image P5 after the adhesion of contaminant particles is corrected by the second blank image BL2. The second blank image BL2 is generated by calculating the median value of the brightness values of each pixel of the multiple sample images PS included in the second sample image group PS2. Therefore, an appropriate corrected image PC can be generated.

FIG. 8 is a diagram showing an example of a corrected image P7B obtained by correcting the sample image P7 after contamination particles have adhered thereto using a blank image P7A after contamination particles have adhered thereto.
The sample image P7 includes a particle image Q9 showing a particle PT of the powder sample SP, a foreign matter image FM showing a foreign matter, and a contaminant particle image CP showing a contaminant particle. Here, the foreign matter corresponds to an example of the first fixed particle FP1. The contaminant particle corresponds to an example of the second fixed particle FP2.
The blank image P7A does not include the particle image Q9, but includes a foreign matter image FM and a contaminant particle image CP.
The blank image P7A is generated by calculating a median value of the luminance values of each pixel of the multiple sample images PS included in the second sample image group PS2 by the generation unit 515. The blank image P7A corresponds to an example of the second blank image BL2.
The corrected image P7B includes the particle image Q8, but does not include the foreign matter image FM or the contaminant particle image CP.

In this way, by correcting the sample image P7 after contamination particles have been attached with the blank image P7A after contamination particles have been attached, an appropriately corrected image P7B can be generated.

As described with reference to FIG. 5, the sample image P4 before the contaminant particles are attached can be corrected with the blank image P4A before the contaminant particles are attached to generate an appropriately corrected image P4B.

When the second fixed particle FP2 is detected by the detection unit 512, the following process is carried out to generate an appropriate corrected image PC.
That is, when the detection unit 512 detects the second fixed particle FP2, the classification unit 513 classifies the sample images PS obtained by photographing the liquid sample SL into a first sample image group PS1 and a second sample image group PS2.
The generating unit 515 generates a first blank image BL1 by calculating a median value of the luminance values of each pixel of the plurality of sample images PS included in the first sample image group PS1, and generates a second blank image BL2 by calculating a median value of the luminance values of each pixel of the plurality of sample images PS included in the second sample image group PS2.
The correction unit 516 calculates the difference between the sample image PS included in the first sample image group PS1 and the first blank image BL1 to correct the sample image PS and generates a corrected image PC. The correction unit 516 calculates the difference between the sample image PS included in the second sample image group PS2 and the second blank image BL2 to correct the sample image PS and generates a corrected image PC.

[4. Processing of the control unit]
Next, the processing of the control unit 12 will be described with reference to FIG. 9 and FIG.
FIG. 9 is a flowchart showing an example of the process of the control unit 12.
First, in step S<b>101 , the imaging control unit 511 causes the camera 8 to capture images of the liquid sample SL at a predetermined period TA, generates a sample image PS, and records the generated sample image PS in the image storage unit 521 .
Next, in step S103, the detection unit 512 executes a fixed particle detection process. The "fixed particle detection process" refers to a process for detecting a fixed particle FP that does not flow within the flow channel 16. Note that in Fig. 9 and Fig. 10, a case will be described in which the fixed particle FP is a second fixed particle FP2.
Next, in step S105, the control unit 12 determines whether or not fixed particles FP have been detected.
When the control unit 12 determines that the fixed particle FP has not been detected (step S105; NO), the process proceeds to step S121. When the control unit 12 determines that the fixed particle FP has been detected (step S105; YES), the process proceeds to step S107.

Then, in step S107, the classification unit 513 classifies the sample images PS obtained by photographing the liquid sample SL into a first sample image group PS1 and a second sample image group PS2.
Next, in step S109, the extraction unit 514 extracts a plurality of sample images PS from the first sample image group PS1.
Next, in step S111, the generation unit 515 generates a first blank image BL1 by calculating the median value of the luminance values of each pixel of the multiple sample images PS extracted in step S109.
Next, in step S113, the correction unit 516 calculates the difference between the sample image PS included in the first sample image group PS1 and the first blank image BL1 to correct the sample image PS and generate a first corrected image PC1. Then, the correction unit 516 records the first corrected image PC1 in the image storage unit 521.

Next, in step S115, the extraction unit 514 extracts a plurality of sample images PS from the second sample image group PS2.
Next, in step S117, the generation unit 515 generates a second blank image BL2 by calculating the median value of the luminance values of each pixel of the multiple sample images PS extracted in step S115.
Next, in step S119, the correction unit 516 calculates the difference between the sample image PS included in the second sample image group PS2 and the second blank image BL2 to correct the sample image PS and generate a second corrected image PC2. Then, the correction unit 516 records the second corrected image PC2 in the image storage unit 521. Then, the process ends.

If the control unit 12 determines that a fixed particle FP has not been detected (step S105; NO), in step S121, the extraction unit 514 extracts multiple sample images PS from the sample image PS obtained by photographing the liquid sample SL.
Next, in step S123, the generating unit 515 generates a blank image BL by calculating the median value of the luminance values of each pixel of the multiple sample images PS extracted in step S121.
Next, in step S125, the correction unit 516 calculates the difference between the sample image PS obtained by photographing the liquid sample SL and the blank image BL, thereby correcting the sample image PS and generating a corrected image PC. Then, the correction unit 516 records the corrected image PC in the image storage unit 521. Then, the process ends.

Each of steps S111, S117, and S123 corresponds to an example of a "generation step." Each of steps S113, S119, and S125 corresponds to an example of a "correction step."

As explained with reference to Figure 9, when the second fixed particle FP2 is detected by the detection unit 512, the generation unit 515 generates a first blank image BL1 by calculating the median value of the brightness values of each pixel of the multiple sample images PS included in the first sample image group PS1.
The correction unit 516 corrects the sample images PS by calculating the difference between the sample images PS included in the first sample image group PS1 and the first blank image BL1 to generate a first corrected image PC1. The generation unit 515 calculates the median value of the luminance values of each pixel of the sample images PS included in the second sample image group PS2 to generate a second blank image BL2.
Then, the correction unit 516 calculates the difference between the sample image PS included in the second sample image group PS2 and the second blank image BL2, thereby correcting the sample image PS to generate a second corrected image PC2.
In this way, each of the sample images PS included in the first sample image group PS1 and the sample images PS included in the second sample image group PS2 can be appropriately corrected.

In this embodiment, the sample images PS included in the first sample image group PS1 are corrected with the first blank image BL1, and the sample images PS included in the second sample image group PS2 are corrected with the second blank image BL2, but the embodiment of the present invention is not limited to this. At least one of a process of correcting the sample images PS included in the first sample image group PS1 with the first blank image BL1 and a process of correcting the sample images PS included in the second sample image group PS2 with the second blank image BL2 may be performed.
For example, the sample images PS included in the first sample image group PS1 may be corrected with the first blank image BL1, and the sample images PS included in the second sample image group PS2 may be discarded. Alternatively, the sample images PS included in the first sample image group PS1 may be discarded, and the sample images PS included in the second sample image group PS2 may be corrected with the second blank image BL2. In these cases, the processing can be simplified.

In addition, in this embodiment, the fixed particles FP include the first fixed particles FP1 and the second fixed particles FP2, but are not limited thereto. The fixed particles FP may be in a form in which the fixed particles FP are not attached to the wall surface of the flow cell 2 on the flow path 16 side when the camera 8 starts to capture the sample image PS, and the fixed particles FP are attached to the wall surface of the flow cell 2 on the flow path 16 side while the camera 8 is capturing the sample image PS, and then peeled off from the wall surface of the flow cell 2 on the flow path 16 side while the camera 8 is capturing the sample image PS.
In this case, for example, the sample image PS may be corrected with the blank image BL for at least one of the image group before the fixed particle FP adheres to the wall surface on the flow path 16 side of the flow cell 2 and the image group after the fixed particle FP has detached from the wall surface on the flow path 16 side of the flow cell 2.

FIG. 10 is a flowchart showing an example of the fixed particle detection process of the control unit 12.
First, in step S201, the detection unit 512 acquires a predetermined number of sample images PS that have been successively captured from the sample images PS obtained by capturing images of the liquid sample SL.
Next, in step S203, the detection unit 512 determines whether or not the luminance values B of pixels arranged at corresponding positions in a predetermined number of sample images PS are equal to or less than a first threshold value.
If the detection unit 512 determines that the luminance values B of the pixels arranged at corresponding positions in the predetermined number of sample images PS are not equal to or less than the first threshold value (step S203; NO), the process proceeds to step S211. If the detection unit 512 determines that the luminance values B of the pixels arranged at corresponding positions in the predetermined number of sample images PS are equal to or less than the first threshold value (step S203; YES), the process proceeds to step S205.

Then, in step S205, the detection unit 512 determines whether or not low-luminance pixels whose luminance value B is equal to or less than the first threshold value are arranged adjacent to each other.
If the detection unit 512 determines that the low-luminance pixels are not arranged adjacent to each other (step S205; NO), the process proceeds to step S211. If the detection unit 512 determines that the low-luminance pixels are arranged adjacent to each other (step S205; YES), the process proceeds to step S207.
In step S207, the detection unit 512 determines whether the number of low-luminance pixels is equal to or greater than a second threshold value. The second threshold value corresponds to an example of the number of "multiple" in "multiple adjacent pixels."
If the detection unit 512 determines that the number of low-luminance pixels is equal to or greater than the second threshold (step S207; YES), the process proceeds to step S209.
Then, in step S209, the detection unit 512 detects the fixed particle FP, and the process returns to step S105 in FIG.
If the detection unit 512 determines that the number of low-luminance pixels is not equal to or greater than the second threshold (step S207; NO), the process proceeds to step S211.
Then, in step S211, the detection unit 512 does not detect the fixed particle FP, and the process returns to step S105 in FIG.

[6. Aspects and Effects]
It will be understood by those skilled in the art that the above-described embodiment is a specific example of the following aspects.

(Section 1)
The particle image analysis device according to the first aspect is a particle image analysis device that analyzes images of the particles contained in a sample image obtained by flowing a liquid sample having particles dispersed therein through a flow path at a predetermined speed and photographing the liquid sample at a predetermined period, and is equipped with a generation unit that generates a blank image based on a plurality of the sample images, and a correction unit that corrects the sample image based on the blank image.

According to the particle image analyzing device described in paragraph 1, a blank image is generated based on a plurality of sample images, and the sample image is corrected based on the generated blank image.
Therefore, since the image of the foreign matter such as the contaminant particles adhering to the flow path can be included in the blank image, the sample image can be appropriately corrected, and therefore, it is possible to prevent the image of the foreign matter such as the contaminant particles adhering to the flow path from being mistaken for the image of the particle.

(Section 2)
In the particle image analyzing device described in paragraph 1, the correction unit corrects the sample image by calculating a difference between the sample image and the blank image.

According to the particle image analyzing device described in paragraph 2, the correction unit corrects the sample image by calculating the difference between the sample image and the blank image.
This allows the sample image to be appropriately corrected, thereby preventing an image of a foreign substance, such as a contaminant particle, adhering to the flow channel from being mistaken for an image of a particle.

(Section 3)
The particle image analysis device described in paragraph 1 or paragraph 2 further comprises a detection unit that detects fixed particles that do not flow within the flow path, and an extraction unit that extracts the plurality of sample images from sample images obtained by photographing the liquid sample based on the detection results of the detection unit.

According to the particle image analysis device described in paragraph 3, fixed particles that do not flow within the flow path are detected, and based on the detection results of the fixed particles, the multiple sample images are extracted from among sample images obtained by photographing the liquid sample.
Therefore, a plurality of sample images for generating a blank image can be appropriately extracted, and therefore an appropriate blank image can be generated.

(Section 4)
In the particle image analysis device described in paragraph 3, the detection unit detects the fixed particle when the brightness values of multiple pixels that are arranged at corresponding positions and adjacent to each other in a predetermined number of consecutively taken images of the sample, which number is two or more, are below a predetermined value.

According to the particle image analysis device described in paragraph 4, the detection unit detects the fixed particle when the brightness values of multiple adjacent pixels arranged at corresponding positions in a predetermined number of consecutively taken images of the sample, which number is two or more, are below a predetermined value.
Therefore, by properly setting the predetermined number of sheets, the number of pixels in the plurality of pixels, and the predetermined value, fixed particles can be properly detected.

(Section 5)
In the particle image analysis device described in paragraph 3 or 4, the device further includes a classification unit that, when the detection unit detects the fixed particle, classifies sample images obtained by photographing the liquid sample into a first sample image group before the fixed particle is detected and a second sample image group after the fixed particle is detected, and the extraction unit extracts the multiple sample images included in the first sample image group when the generation unit generates the blank image to be used for correcting the sample images included in the first sample image group, and extracts the multiple sample images included in the second sample image group when the generation unit generates the blank image to be used for correcting the sample images included in the second sample image group.

According to the particle image analysis device described in paragraph 5, when the generation unit generates the blank image to be used for correcting the sample images included in the first sample image group, the extraction unit extracts the multiple sample images included in the first sample image group, and when the generation unit generates the blank image to be used for correcting the sample images included in the second sample image group, the extraction unit extracts the multiple sample images included in the second sample image group.
Therefore, a plurality of sample images for generating a blank image can be appropriately extracted, and therefore an appropriate blank image can be generated.

(Section 6)
In the particle image analysis device described in any one of paragraphs 1 to 5, the specified speed and the specified period are each set so that the particles flowing within the flow path are not included in two successively captured images of the sample.

According to the particle image analysis device described in paragraph 6, each of the specified speed and the specified period is set so that the particles flowing within the flow path are not included in two successively captured images of the sample.
Therefore, it is possible to prevent the image of the same particle from being captured multiple times.

(Section 7)
In the particle image analysis device described in any one of paragraphs 1 to 6, the generation unit generates the blank image by calculating a median value of brightness values of each pixel of the plurality of sample images.

According to the particle image analyzing device described in item 7, the generating unit generates the blank image by calculating a median value of brightness values of each pixel of the plurality of sample images.
Therefore, a proper blank image can be generated.

(Section 8)
In the particle image analysis device described in any one of paragraphs 1 to 6, the generation unit generates the blank image by calculating an average value of brightness values of each pixel of the plurality of sample images.

According to the particle image analyzing device described in item 8, the generating unit generates the blank image by calculating an average value of the brightness values of each pixel of the plurality of sample images.
Therefore, a proper blank image can be generated.

(Section 9)
The particle image analysis method of the particle image analysis device relating to the second aspect is a particle image analysis method of a particle image analysis device that analyzes images of the particles contained in a sample image obtained by flowing a liquid sample in which particles are dispersed through a flow path at a predetermined speed and photographing the liquid sample at a predetermined period, and includes a generation step of generating a blank image based on a plurality of the sample images, and a correction step of correcting the sample image based on the blank image.

The particle image analysis method of the particle image analyzer described in paragraph 9 provides the same effects as the particle image analyzer described in paragraph 1.

(Article 10)
The particle image analysis program relating to the third aspect is a particle image analysis program that analyzes images of the particles contained in a sample image obtained by flowing a liquid sample having particles dispersed therein through a flow path at a predetermined speed and photographing the liquid sample at a predetermined period, and causes a computer to function as a generation unit that generates a blank image based on a plurality of the sample images, and a correction unit that corrects the sample image based on the blank image.

The particle image analysis program described in paragraph 10 provides the same effects as the particle image analysis device described in paragraph 1.

7. Other embodiments
It should be noted that the particle image analysis device 1 according to this embodiment is merely an example of an aspect of the particle image analysis device according to the present invention, and any modification and application is possible within the scope that does not deviate from the gist of the present invention.
For example, in this embodiment, the control unit 12 of the particle image analysis device 1 includes an imaging control unit 511, a detection unit 512, a classification unit 513, an extraction unit 514, a generation unit 515, a correction unit 516, and an image storage unit 521, but the embodiment of the present invention is not limited to this. For example, the control unit 12 of the particle image analysis device 1 may include the imaging control unit 511 and the image storage unit 521, and a control device configured as a personal computer or the like separately from the particle image analysis device 1 may include the detection unit 512, the classification unit 513, the extraction unit 514, the generation unit 515, and the correction unit 516.

Furthermore, each functional unit shown in FIG. 1 indicates a functional configuration, and the specific implementation form is not particularly limited. In other words, it is not necessary to implement hardware that corresponds to each functional unit individually, and it is of course possible to implement a configuration in which one processor executes a program to realize the functions of multiple functional units. Furthermore, some of the functions realized by software in the above embodiment may be realized by hardware, or some of the functions realized by hardware may be realized by software.

The processing units in the flowcharts shown in Figures 9 and 10 are divided according to the main processing content in order to make the processing of the control unit 12 easier to understand. There is no limitation to the manner in which the processing units are divided or the names shown in the flowcharts of Figures 9 and 10, and they can be divided into even more processing units depending on the processing content, or one processing unit can be divided to include even more processes. Furthermore, the processing order of the above flowcharts is not limited to the example shown.

The control unit 12 of the particle image analyzer 1 causes the processor 51 included in the control unit 12 to execute a control program PG corresponding to the particle image analysis method of the particle image analyzer 1. The control program PG can also be recorded in a computer-readable recording medium. The recording medium can be a magnetic or optical recording medium or a semiconductor memory device. Specifically, portable or fixed recording media such as a flexible disk, HDD, CD-ROM (Compact Disk Read Only Memory), DVD, Blu-ray (registered trademark) Disc, magneto-optical disk, flash memory, and card-type recording media can be used. The recording medium can also be a non-volatile storage device such as a RAM, ROM, or HDD that is an internal storage device included in the control unit 12. The control program PG can also be stored in a server device or the like, and the control program PG can be downloaded from the server device to the control unit 12.

REFERENCE SIGNS LIST 1 Image analysis type particle analyzer 2 Flow cell 4 Liquid sample supply mechanism 6A Light source device 8 Camera 10 Focus mechanism 12 Control unit (computer)
16 Flow path 22 Liquid delivery pump 24 Liquid sample storage container 32 Waste liquid tank 34 Measurement light 38 Telecentric microscope 40 Telecentric lens 42 Lens driving mechanism 51 Processor 511 Imaging control section 512 Detection section 513 Classification section 514 Extraction section 515 Generation section 516 Correction section 52 Memory 512 Image storage section BC, BS, BB Brightness value BX Average brightness value BL Blank image BL1 First blank image BL2 Second blank image CP Contamination particle image FM Foreign matter image FP Fixed particle FP1 First fixed particle FP2 Second fixed particle PC Correction image PG Control program (particle image analysis program)
PS Sample image PS1 First sample image group PS2 Second sample image group PT Particles SL Liquid sample SP Powder sample TA Predetermined period VA Predetermined speed

Claims (9)

A particle image analyzer for analyzing images of particles contained in a sample image obtained by flowing a liquid sample having particles dispersed therein through a flow path at a predetermined speed and photographing the liquid sample at a predetermined cycle, comprising:
A generating unit that generates a blank image based on a plurality of the sample images;
a correction unit that corrects the sample image based on the blank image;
a detection unit for detecting immobile particles not flowing through the flow channel;
an extracting unit that extracts the plurality of sample images from sample images obtained by photographing the liquid sample based on a detection result of the detecting unit;
A particle image analysis device comprising: The correction unit corrects the sample image by calculating a difference between the sample image and the blank image.
The particle image analysis device according to claim 1 . the detection unit detects the fixed particle when the luminance values of a plurality of pixels that are arranged at corresponding positions and adjacent to each other in a predetermined number (two or more) of the sample images that have been continuously captured are equal to or less than a predetermined value.
The particle image analysis device according to claim 1 . a classification unit that, when the detection unit detects the fixed particles, classifies sample images obtained by photographing the liquid sample into a first sample image group before the fixed particles are detected and a second sample image group after the fixed particles are detected,
The extraction unit is
When the generating unit generates the blank image to be used for correcting the sample images included in the first sample image group, the generating unit extracts the sample images included in the first sample image group,
When the generating unit generates the blank image used for correcting the sample images included in the second sample image group, the generating unit extracts the sample images included in the second sample image group.
The particle image analyzer according to claim 1 or 3 . the predetermined speed and the predetermined period are each set so that the particles flowing through the flow channel are not included in two consecutively captured images of the sample.
The particle image analyzer according to any one of claims 1 to 4 . the generating unit generates the blank image by calculating a median value of brightness values of each pixel of the plurality of sample images.
The particle image analyzer according to any one of claims 1 to 5 . the generating unit generates the blank image by calculating an average value of luminance values of each pixel of the plurality of sample images.
The particle image analyzer according to any one of claims 1 to 5 . A particle image analysis method for a particle image analyzer, comprising the steps of: flowing a liquid sample having particles dispersed therein through a flow path at a predetermined speed; photographing the liquid sample at a predetermined cycle; and analyzing images of the particles contained in the sample images obtained by the photographing;
generating a blank image based on the plurality of sample images;
a correction step of correcting the sample image based on the blank image;
a detection step of detecting immobile particles not flowing within the flow channel;
an extraction step of extracting the plurality of sample images from sample images obtained by photographing the liquid sample based on a detection result in the detection step;
A particle image analysis method comprising: A particle image analysis program for analyzing images of particles contained in a sample image obtained by flowing a liquid sample having particles dispersed therein through a flow path at a predetermined speed and photographing the liquid sample at a predetermined cycle, the program comprising:
Computer,
A generating unit that generates a blank image based on the plurality of sample images;
a correction unit that corrects the sample image based on the blank image;
A detection unit for detecting immobile particles that do not flow through the flow channel; and
an extraction unit that extracts the plurality of sample images from sample images obtained by photographing the liquid sample based on a detection result of the detection unit;
A particle image analysis program that acts as a

Images