JP2009168749A - Device and method for particle analysis - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device and method for particle analysis which can discriminate a boundary between particles even in the image wherein the boundary of the particles could not be discriminated with a single threshold because of gradual changes in brightness of adjacent particles. <P>SOLUTION: The particle analysis device 100 includes: a converting means 4a which creates the image converted into index colors corresponding to brightness of each particle for each particle in the obtained image of particles; a color look-up table 4b which stores a symbol allocated to each color of the index colors; and a particle analysis unit 4c which analyzes whether each particle is the same or different from the symbols and the image data of the particles converted into the index colors. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a particle analysis apparatus that analyzes features such as the number and shape of particles using an image, and a particle analysis method.

2. Description of the Related Art Conventionally, a method and an apparatus for measuring an average particle diameter of particles by imaging a metal crystal structure or a ferrite crystal with a camera and binarizing a crystal grain boundary of the captured image have been proposed (for example, , See Patent Document 1).
JP-A-8-101114

  In the conventional method and apparatus for binarizing an image, it is difficult to perform particle analysis on an image in which the brightness of adjacent particles gradually changes and the boundary between adjacent particles cannot be determined with one threshold value. There is a problem.

  In order to solve the above-mentioned problems, the present invention provides a conversion means for creating an image obtained by converting each particle in the acquired particle image into an index color corresponding to the brightness of each particle, and each of the index colors. Analyzing whether each particle is the same or different from a color look-up table storing symbols assigned to colors, and the image data of the particles converted to the index color. There is provided a particle analyzing apparatus comprising a particle analyzing unit.

  Further, the present invention converts each particle of the particle image acquired by the image acquisition means into an index color corresponding to the luminance of each particle, and uses a symbol assigned to each color of the index color. Provided is a particle analysis method characterized by performing particle analysis.

  According to the present invention, there is provided a particle analysis apparatus and a particle analysis method capable of determining a particle boundary even in an image in which the particle boundary cannot be determined with a single threshold because the brightness of adjacent particles is gradually changed. Can be provided.

  A particle analysis method and a particle analysis apparatus according to an embodiment of the present invention will be described with reference to the drawings. The following embodiments are merely for facilitating understanding of the invention, and excluding additions and substitutions that can be performed by those skilled in the art without departing from the technical idea of the present invention. It is not intended. This is the same even after correction and correction.

  First, the reason why an image cannot be satisfactorily processed by the conventional binarization process based on one threshold will be briefly described below.

  FIG. 5 is a schematic diagram of an image acquired from a specimen, (a) is a schematic diagram of a particle image, and (b) is a schematic diagram of a luminance signal at line AA.

  In FIG. 5, an image a schematically shows a case where three particles c, d, and e having different brightness exist in a background b having gradation. When a luminance signal is detected for these particles c, d, and e along the line AA, the luminance changes stepwise from the particles c to e as shown in (b). In such a case, it is not possible to set a single threshold value for the luminance signal to detect the boundaries of each particle at the same time, and it is not possible to perform particle analysis using conventional binarization processing. If analysis is to be performed by binarization processing, it is necessary to perform a complicated process of detecting each particle boundary by setting a threshold value a plurality of times in order to detect each particle boundary.

  The particle analysis method and the particle analysis apparatus according to the present embodiment enable particle analysis even for the above-described image.

  Hereinafter, a particle analysis method and a particle analysis apparatus according to the present embodiment will be described.

  FIG. 1 is a schematic configuration diagram of a particle analyzing apparatus according to an embodiment.

  In FIG. 1, a particle analyzing apparatus 100 includes a microscope 2 having a stage 6 on which a specimen 1 is placed, an imaging apparatus 3 (for example, a digital camera, hereinafter simply referred to as “camera”) that captures an image of the specimen 1, a camera 3 includes a particle analysis device 4 (for example, a personal computer, hereinafter simply referred to as “PC”) that processes the image acquired in 3 and performs particle analysis, and a monitor 5 that displays the acquired image and the image processed image. . Further, the particle analysis device 4 includes an index color conversion unit 4a, a color lookup table 4b, and a particle analysis processing unit 4c including feature extraction means, which will be described later.

  FIG. 2 is a diagram schematically showing a particle image of the specimen 1 acquired by the camera 3. The image 10 schematically shows a case where four different particles 11, 12, 13, and 14 exist in a background 15 having gradation. This image 10 has luminance characteristics similar to those in FIG. 5, and it is difficult to detect the grain boundary by the conventional binarization process. The background 15 is white in the figure for the sake of explanation.

  In FIG. 2, an image 10 shows an image obtained by converting the color particle image of the sample 1 acquired by the camera 3 into an index color by the index color conversion processing unit 4 a of the PC 4. The image 10 shows a case where, for example, the index color is converted into 5 out of 8 colors. Here, the particles 11 are converted to red, the particles 12 to blue, the particles 13 to green, and the particles 14 to yellow. The background 15 is converted into a color different from the above four colors.

  Note that the number of colors used for the index color conversion is configured to be appropriately set according to the particle distribution characteristics of the sample 1. Also, since existing software is used as a conversion method for converting a particle image into an index color, detailed description thereof is omitted.

  Moreover, even when the particles are in contact with each other as shown in FIG. 2 or when they are isolated, they can be converted into an index color by the same processing.

  The particle image that has undergone the index color conversion is subjected to particle analysis processing using a number (hereinafter referred to as “pallet number”) assigned to each index color stored in the color lookup table 4b of the PC 4. In this embodiment, numbers are used, but other symbols such as alphabets may be used.

  FIG. 3 schematically shows a palette number in each pixel of the particle image converted into the index color.

  In FIG. 3, red is assigned palette number 1, green is assigned palette number 3, blue is assigned palette number 5, and yellow is assigned palette number 7 in the lookup table. Then, the particle analysis processing unit 4c regards all the portions where the same pallet number is continuously adjacent as the same particle, and sets the boundary between the pixels where the pallet number is changed to the different pallet number as the grain boundary 20 (in FIG. 3). (Indicated by a thick solid line). That is, it is analyzed whether the particles are the same or different. In addition, even if the pallet numbers assigned to the plurality of particles are the same, if the pallet numbers are not continuous, it is recognized that the plurality of particles are different particles. These processes are executed by the particle analysis processing unit 4c built in the PC 4.

  The particle analysis processing unit 4c of the PC 4 performs a process of regarding regions where the same palette numbers are continuous as the same particles from the pixel data of the particle image 10 converted into the index color. Thereby, the particle analyzer 100 can analyze the characteristics such as the number of particles, the average particle diameter, or the area.

  In the above description, the case where the image 10 is a color image has been described. However, in the case of a grayscale image, the same can be performed to classify particles and perform particle analysis.

  FIG. 4 schematically shows an image 30 when the grain boundary P exists so as to divide the particle 14 in the particle 14. Like this image 30, some specimens 1 may have grain boundaries P with a narrow width converted into index colors of different colors in the particles 14 converted into index colors of the same color. In such a case, the width of the grain boundary P is calculated from the pixel data of the grain boundary P, and when the calculated width is smaller than the preset threshold width, the grain boundary P is not regarded as one particle. It is regarded as the grain boundary P and analyzed by the particle analysis processing unit 4c. Depending on the width of the grain boundary P, the particles 14a and 14b may be regarded as the same particle 14 and analyzed. The threshold width can be changed as appropriate depending on the sample.

  According to this technology, when the conversion is performed using the index color, even though it is actually a different particle, it is defined as the same index color, so that it is erroneously determined that it is the same adjacent particle. Can be prevented.

  In the above description, an image acquired from the camera 3, an image subjected to index color conversion, an image subjected to particle analysis processing, and the like are each displayed on the monitor 5 and configured to be observable and operated by the user. Needless to say.

  As described above, according to the particle analysis method and the particle analysis apparatus according to the present embodiment, even if the particle image is difficult to be binarized, the index color is converted into the index color after each particle is converted into the index color. By using the pallet number assigned to, it is possible to easily analyze the characteristics of the sample such as the area, number, average particle diameter, or distribution statistics thereof.

1 is a schematic configuration diagram of a particle analyzing apparatus according to an embodiment of the present invention. It is the figure which showed typically the result of carrying out index color conversion of the particle image of the sample acquired with the camera. The palette number in each pixel of the particle image converted into index color is typically shown. The schematic diagram in the case where a grain boundary exists so as to divide the particle in the particle is shown. The schematic diagram of the image acquired from the sample is shown, (a) The schematic diagram of a particle image, (b) shows the schematic diagram of the luminance signal in AA line, respectively.

Explanation of symbols

1 Specimen 2 Microscope 3 Imaging device (Camera)
4 Particle analyzer (PC)
5 Monitor 6 Stage 10, 30 Image 11, 12, 13, 14 Particle 15 Background 20 Boundary (grain boundary)
P Grain boundary 100 Particle analyzer

Claims (4)

Conversion means for creating an image converted into an index color corresponding to the brightness of each particle for each particle in the acquired particle image;
A color look-up table storing a symbol assigned to each color of the index color;
From the symbol and the image data of the particles converted into the index color, a particle analysis unit for analyzing whether each of the particles is the same or different,
A particle analyzing apparatus comprising:   The particle analysis apparatus according to claim 1, wherein the particle analysis unit determines that the consecutive particles having the same symbol are the same particles.   When the particle analysis unit includes a region composed of different index colors in the particles converted to the same index color, the particles of the same color index color are changed to the index colors of the different color. The particle analyzing apparatus according to claim 1, wherein the particle analyzing apparatus determines that the particles are different particles having a region as a boundary.   Converting each particle of the particle image acquired by the image acquisition means into an index color corresponding to the luminance of each particle, and performing particle analysis using a symbol assigned to each color of the index color Characteristic particle analysis method.

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