JP3660936B1 - Bubble measuring method and bubble measuring device for hardened concrete - Google Patents

Abstract

An object of the present invention is to provide a hardened concrete bubble that has solved all of the problems such as the length of extraction time for extracting the bubble part, the troublesome extraction work, the complexity of the extraction device or tooling, and the lack of reliability of the extraction result. To provide a measurement method and apparatus.
A first captured image captured by a digital camera by illumination of a first illumination means having a large angle of illumination light with respect to a measurement region of a measurement target surface of a test piece of hardened concrete, and the measurement region The measurement area is illuminated with a first bubble image that has been subjected to image processing on a density difference image with respect to a second captured image captured by illumination of the second illumination means with a small angle of illumination light formed, and with an illuminance exceeding a predetermined level Using the second bubble image obtained by performing image processing on the third captured image of the measurement region imaged by illumination from the illumination unit, the feature of the image of the opening of the hole that wraps the bubble appearing in the measurement region A method and apparatus for measuring bubbles contained in hardened concrete by performing a quantity extraction process.
[Selection] Figure 1

Description

The present invention relates to a method for measuring a bubble content state such as the content, size, and distribution of bubbles contained in a hardened concrete or other similar bubble-containing object that is intentionally included with bubbles in advance, and a measurement apparatus therefor. More specifically, the cut surface of the test piece cut for the above measurement is imaged with a digital camera, and the image of the open end of the hole enclosing the bubbles appearing on the cut surface is extracted from the captured image. The present invention relates to a method and apparatus.

Conventionally, several methods have been taken to extract the shape of bubble holes for measuring bubbles contained in hardened concrete.
An example of the first method is that, as disclosed in Japanese Patent Laid- Open No. 2-77648, cyanoacrylate added with a fluorescent dye is applied to the measurement surface of a concrete sample so as to enter the pores existing in the sample. When the cyanoacrylate is solidified by lifetime, it is polished, and the measurement surface of the sample is irradiated with ultraviolet light so that only the fixed cyanoacrylate portion emits light, and the luminance distribution at that time is a certain threshold value. The image processing can be performed by binarizing the image.
An example of the second method is as disclosed in Japanese Patent Publication No. 07-006921, in which an imaging device is provided facing the surface of a sample having a bubble hole on the surface, and light is emitted from one direction to three directions on the surface of the sample. , The images in each irradiation direction are captured, the brightness up, rp, and lp at the same position of each image is obtained, and the three-dimensional coordinates including the X, Y, and Z axes representing the brightness are set. Set a triangle (1, 1, 1) plane with vertices of (1, 0, 0), (0, 1, 0), (0, 0, 1), and set all three coordinate values to the same point. A passing vector is a reference vector, a point where the reference vector intersects the triangle (1, 1, 1) plane is a reference point, and brightness at the same position of each pixel is expressed by coordinates (up, rp, lp). The point where the vector passing through the origin (0, 0, 0) intersects the triangle (1, 1, 1) plane A bubble tissue measurement method in which a degree point, a reference point as a base point, a vector up to a brightness point as a brightness vector, and when the magnitude of the brightness vector is larger than a predetermined value, it is determined that there is a bubble at the same position in each image. is there. This method automatically performs the work of separating the cement paste part and the aggregate part by macro measurement. However, in reality, it is difficult to determine the threshold level of binarization because various aggregates are mixed. Work to judge while looking at the microscope is required. Further, there is a problem that the measurement process takes too much time.
JP 02-77648 A JP 07-006921

Each of the conventional technologies requires special processing on the measurement object, the measurement to extract the bubble cross-section takes a long time, and the skill level in the recognition of bubble holes, the measurement method, and the operation of the measurement device And some of the practical problems such as lack of reliability of the extracted results due to human error and the prone to human error due to artificial measurement methods ing.
The problem to be solved is to provide a bubble hole extraction technique that solves all of these problems, and further, a method and an apparatus for measuring bubbles in hardened concrete by this bubble hole extraction technique.

The first main means is to set the measurement target surface using a part of the hardened concrete containing bubbles (specifically, create the measurement target surface by cutting and polishing, etc.) A method for measuring bubbles contained in hardened concrete by measuring the open end shape of a hole that encloses open bubbles,
The image is captured by a digital camera by the illumination of the first illumination means arranged facing the measurement area of the measurement target surface so that the inner surface of the hole surrounding the substantially spherical bubble appearing on the measurement target surface is not shaded. Illumination of the second illuminating means arranged to face the measurement area so as to illuminate the first captured image of the measured area and the inner surface of the hole surrounding the substantially spherical bubble except for the vicinity of the opening end. Using the density difference image created by the density difference processing between the second captured image of the measurement area captured by the digital camera with the digital camera, the feature amount of the image of the open end of the hole surrounding the bubble appearing in the measurement area By performing the extraction process, the bubbles contained in the hardened concrete are measured. By this measuring method, it is possible to measure air bubbles (the shape is nearly spherical) artificially contained in the hardened concrete.
The first illumination means and the second illumination means are preferably diffused light illumination means.

  In this case, it is a preferable method to binarize the density difference image and extract the image of the hole surrounding the bubble to perform the feature amount extraction processing.

The second main means is to set the measurement target surface using a part of the hardened concrete containing air bubbles, and to measure the shape of the opening end of the hole that encloses the air bubbles opening in the measurement target surface. A method for measuring bubbles contained therein,
The image is captured by a digital camera by illumination of the first illumination means arranged facing the measurement area of the measurement target surface so that the inner surface of the hole surrounding the substantially spherical bubble appearing on the measurement target surface is not shaded. Of the second illuminating means arranged so as to face the measurement area so as to illuminate the first captured image of the measurement target surface and the inner surface of the hole enclosing the substantially spherical bubble except in the vicinity of the opening end. A first bubble image that is a density difference image created by density difference processing between the second captured image of the measurement region captured by the digital camera with illumination;
In the picked-up image, the bubble shape of the second form in which the concentration level of both the inner surface of the substantially spherical bubble hole and the plane part in the measurement region is high, the cross-sectional shape is irregular, and the depth is larger than the width of the narrow part of the entrance. The second form of the bubble is in the third captured image of the measurement region captured by illumination from the illumination means such that the density level of the image of the image is low and these high and low density levels can be easily discriminated. Using the second bubble image that has been subjected to the process of extracting the hole image, the feature amount extraction process of the image of the opening of the hole that wraps the bubble appearing in the measurement region is performed.
By this measurement method, the bubble of the bubble (entrapped air) naturally formed due to the manufacturing process, and the depth of the measurement object surface is larger than the width of the narrow part of the cross section of the hole entrance, It is possible to simultaneously extract both the holes and the holes of the bubbles (entrained air, whose shape is almost spherical) artificially contained in the hardened concrete with a medicine.

In the second main means, as a more specific means, a binarization process is performed on each of the first bubble image and the second bubble image to obtain a first binarized image and a second binarized image, respectively. The first binarized image and the second binarized image are combined to form one synthetic bubble image, and the feature of the opening end of the hole surrounding the measurement target bubble that appears in the measurement region with respect to the synthetic bubble image A quantity extraction process can be performed.
Here, as a specific method of synthesis, there is a method of performing logical calculation by exclusive OR between the first binarized image and the black and white inverted image of the second binarized image.

  In the second main means, the illumination means for capturing the third captured image is an illumination means for irradiating diffused light from a plurality of angles (elevation angles when viewing the illumination means from the measurement area) with respect to the measurement area. It can be.

  In the second main means, the illumination means for capturing the third captured image is a combination of the first illumination means and the diffused light illumination means consisting only of the second illumination means, or the first illumination means, the second illumination means and others. It can be made by a combination of diffused light illumination means comprising the illumination means.

Further, in the second main means, the illuminating means for capturing the third captured image may be the third illuminating means specially provided for capturing the third captured image, or the first illuminating means. It doesn't matter. The third illumination means is preferably a diffused light illumination means.

The third main means is to set the measurement target surface using a part of the hardened concrete containing air bubbles, and measure the shape of the opening end of the hole that encloses the air bubbles opening in the measurement target surface. An apparatus for measuring contained bubbles,
A digital camera that images the measurement area of the measurement target surface,
An image processing apparatus for performing image processing on an image captured by a digital camera;
First illumination means arranged opposite to the measurement region to illuminate so that the inner surface of the hole surrounding the substantially spherical bubble appearing in the measurement region is not shaded, and the inner surface of the hole surrounding the substantially spherical bubble The second illuminating means arranged as opposed to the measurement region to illuminate in the shade except for the vicinity of the opening end is provided as the illuminating means,
In the image processing apparatus, between the first captured image of the measurement area captured by the digital camera by the illumination of the first illumination means and the second captured image of the measurement area captured by the digital camera by the illumination of the second illumination means. Using the density difference image created by the density difference processing, the measurement of the bubbles contained in the hardened concrete is performed by performing the feature amount extraction processing of the image of the opening end of the hole surrounding the bubbles appearing in the measurement region . With this measuring device, it is possible to measure bubbles (the shape is nearly spherical) artificially contained in hardened concrete.
The first illumination means and the second illumination means are preferably diffused light illumination means.

  In the third main means, the density difference image is binarized to extract the image of the hole surrounding the bubble, and the feature amount extraction process can be performed.

The fourth main means is to set the measurement target surface using a part of the hardened concrete containing air bubbles, and measure the shape of the opening end of the hole enclosing the air bubbles opening in the measurement target surface. An apparatus for measuring contained bubbles,
A digital camera that images the measurement area of the measurement target surface,
An image processing apparatus for performing image processing on an image captured by a digital camera;
First illumination means arranged opposite to the measurement region to illuminate so that the inner surface of the hole surrounding the substantially spherical bubble appearing in the measurement region is not shaded, and the inner surface of the hole surrounding the substantially spherical bubble At least a second illuminating means arranged opposite to the measurement region to illuminate in the shade except for the vicinity of the opening end, as an illuminating means,
In the image processing apparatus, between the first captured image of the measurement area captured by the digital camera by the illumination of the first illumination means and the second captured image of the measurement area captured by the digital camera by the illumination of the second illumination means A first bubble image that is a density difference image created by density difference processing;
In the picked-up image, the bubble shape of the second form in which the concentration level of both the inner surface of the substantially spherical bubble hole and the plane part in the measurement region is high, the cross-sectional shape is irregular, and the depth is larger than the width of the narrow part of the entrance. The second form of the bubble is in the third captured image of the measurement region captured by illumination from the illumination means such that the density level of the image of the image is low and these high and low density levels can be easily discriminated. It is included in the hardened concrete by performing the feature amount extraction processing of the image of the opening end of the hole surrounding the bubble appearing in the measurement region using the second bubble image subjected to the processing for extracting the hole image. Measure bubbles.
With this measuring device, bubble holes naturally formed due to the manufacturing process (entrapped air), which have a deep section from the surface to be measured, and irregularly shaped bubble holes, and artificially hardened concrete with drugs It is possible to simultaneously extract both pores of bubbles (entrein air, shape is almost spherical).

In the fourth main means, binarization processing is performed on each of the first bubble image and the second bubble image to obtain a first binarized image and a second binarized image, respectively. And the second binarized image are combined into one synthetic bubble image, and the feature amount extraction processing of the image of the opening end of the hole surrounding the measurement target bubble appearing in the measurement region is performed on the synthetic bubble image. Thus, it is possible to perform bubble measurement.
Here, as a specific method of synthesis, there is a method of performing logical calculation by exclusive OR between the first binarized image and the black and white inverted image of the second binarized image.

  Illumination for illuminating diffused light from a plurality of angles (elevation angles when the illumination means is viewed from the measurement area) with respect to the measurement area by the illumination means when capturing the third captured image according to the fourth main means It can be configured by means.

  Further, according to the fourth main means, the illumination means for capturing the third captured image is a combination of the diffused illumination illumination means consisting of only the first illumination means and the second illumination means, or the first illumination means and the second illumination means. It can be configured by a combination of diffused light illumination means including illumination means and other illumination means.

Still further, according to the fourth main means, the illumination means for picking up the third picked-up image is either the third lighting means specially provided for picking up the third picked-up image or the first lighting means. It doesn't matter. The third illumination means is preferably a diffused light illumination means.

  The present invention has solved practical problems associated with the prior art with respect to a method and a device for measuring bubbles in hardened concrete. In other words, the measurement object had to be specially processed, the measurement for extracting the bubble cross-section took a long time, and the degree of skill in the recognition and measurement method and measurement device operation of the bubble hole Practical problems such as lack of reliability of the extracted results due to the fact that it was necessary and human error was likely to occur due to an artificial measurement method were solved, resulting in a short In time, it became possible to provide a bubble measuring device for hardened concrete as a highly reliable practical machine capable of stably measuring without subjecting the measurement operator.

  The best mode for carrying out the present invention will be described below together with examples.

FIG. 1 is a block diagram showing the arrangement of components of the imaging system of the bubble measuring device for hardened concrete and the components from the camera to the image processing.
The hardened concrete sample 10 which is cut so that the upper and lower surfaces are parallel and the measurement target surface 11 of at least two parallel surfaces is adjusted to a predetermined roughness by means of polishing or the like is (Y, + Y direction) is placed on the stage 20 that moves left and right (-X, + X direction), and is placed toward the digital camera 30 so that the measurement target surface 11 is perpendicular to the optical axis 32 of the digital camera 30. Yes. Also, small light sources such as LEDs are closely arranged on the surface of the ring that has a ring shape, a square cross section, and includes a side (bold line display) facing the inside of the square to form a light emitting surface. The first illuminating means 41 and the second illuminating means 42 that irradiate diffused light in the direction from the light emitting surface to the measurement target surface 11 place the center of each ring on the optical axis 32 of the digital camera 30, and set the hardened concrete sample. Each ring is arranged so as to be substantially parallel to ten measurement target surfaces 11.
The digital camera 30 is focused by the digital camera 30 itself so that the focal point is on the measurement target surface 11 or by adjusting the position of the digital camera 30 or the height position of the stage 20.
A single imaging region (hereinafter also referred to as a measurement region) by the digital camera 30 is a small region centered on the intersection with the optical axis 32 of the digital camera on the measurement target surface 11, and the region size is the digital camera 30. Depending on the CCD size and the magnification of the lens 31. Incidentally, in this embodiment, the measurement area size is about 4.7 mm × 4.4 mm.
12 to 14 show examples of the bubble holes appearing on the measurement target surface. The bubble holes are 12, 13 and 14, and the measurement target surface 11 has open ends 12a, 13a, 14a-1 and 14-b corresponding to the intersection lines of the bubble hole and the measurement target surface 11, respectively. The broken line portion schematically shows the shape of the bubble hole in the depth direction (not visible in the shade). Reference numeral 12 c (two-dot chain line portion) schematically shows a portion of the substantially spherical bubble hole 12 that is not cut out by the preparation of the sample 10. In FIG. 14, the long bubble hole 14 has two open ends 14a-1to14a-2.

The first illumination means 41 is an angle formed by a line connecting the intersection of the measurement target surface 11 of the hardened concrete sample 10 and the optical axis 32 of the digital camera 30 and the center of the light emission surface of the first illumination means 41 and the measurement target surface 11. The size and the arrangement position of α are determined so that the irradiation light reaches the bottom surface 12 b of the substantially spherical bubble hole 12 existing (appearing) in the measurement region on the measurement target surface 11. ing. Incidentally, in this embodiment, the angle α is set to 40 degrees. In general, the angle α should be adjusted according to the size of the light emitting surface of the first illumination unit 41, the angle of the light emitting surface, and the distance from the measurement region, and is set to a range of approximately 30 degrees or more. Become.
The second illumination means 42 measures the angle β formed by the line connecting the intersection between the measurement target surface 11 of the hardened concrete sample 10 and the optical axis 32 and the center of the light emitting surface of the second illumination means 42 and the measurement target surface 11. The size and arrangement position are determined so that the inside of the substantially spherical bubble hole 12 existing in the measurement region on the surface 11 is shaded. Note that the smaller the β is, the smaller the bubble hole 12 is observed by increasing the concentration of the inclined portion at the inlet of the bubble hole 12 (near the hole side of the opening end 12a of the bubble hole 12 to the measurement target surface 11). The image of the bubble 12 hole is close to the real thing. In this case, however, it is natural that the light emitting surface of the second illumination means 42 must be reduced in size as β decreases. Incidentally, in this embodiment, the angle β is set to 6 degrees. In general, the angle β should be adjusted according to the size of the ring of the second illumination means 42, the angle of the light emitting surface, and the distance from the measurement region, and is set to a range of approximately 0 ° to 15 °. It will be.

Imaging the shape of the open end (12a, 13a or 14a) of the bubble hole (12, 13 or 14) existing on the measurement target surface 11 (generally referred to as a bubble cross-sectional shape in the industry) by the above-described hardened concrete bubble measuring device. Extracting and measuring various characteristics of the bubbles contained in the hardened concrete sample 10 will be described.
First, the measurement operator moves the stage 20 in the XY directions, and aligns the center of the area (measurement area) to be measured on the measurement target surface 11 of the hardened concrete sample 10 on the optical axis 32. Next, the digital camera 30 is focused. Thereafter, the measurement region is imaged by the digital camera 30, and the result is sent to the image processing device 50, and the image processing device 50 detects the opening end of the bubble hole existing in the portion included in the measurement region of the measurement target surface 11. An image is extracted. The extraction of the image of the open end of the bubble hole is performed by a series of methods described in the next paragraph, which is a feature of the present invention. The extracted bubble image is extracted with features, and is generally handled and processed so as to conform to the method defined by the ASTM standard, and various characteristics of bubbles in the measurement area of hardened concrete are measured. Is done.
Naturally, from the viewpoint of measurement reliability, when various characteristics of bubbles are measured in a plurality of measurement regions on the measurement target surface of the hardened concrete sample 10, and representative values of various characteristics of the bubbles of the hardened concrete sample 10 are obtained. There is also. At this time, every time measurement of one measurement area is completed, the stage is moved to set a new measurement area. Note that the parallelism between the measurement target surface 11 of the hardened concrete sample 10 and the sample mounting surface of the stage 20 is within the range of the depth of field of the digital camera 30, so that the focusing of the digital camera 30 is performed before each measurement. There is no need to do.
Further, when the measurement target surface 11 cannot be parallel to the sample mounting surface of the stage 20 prior to the measurement, focusing prior to each measurement can be automated by providing an automatic focusing means.

Next, a series of methods for extracting the image of the open end of the bubble hole existing on the measurement target surface 11 in the measurement region will be described.
(1) First Step The first illumination means is turned on, an image is taken, and the image is taken into the image processing apparatus 50. The captured image at this time is shown in FIG. 4 (photograph). The attention part is not all but can be identified with a symbol. The symbols are W for the white aggregate part, B for the black aggregate part, SB for the shallow bubble hole part (substantially spherical bubble hole part), and DB for the deep bubble hole part. The shallow bubble hole portion SB is almost an image of the open end of a substantially spherical bubble hole, and thus appears to have a nearly circular shape. In addition, Table 1 shows the density level of the target portion of the image.
As is apparent from FIG. 4 and Table 1, the cement paste, the white aggregate, and the shallow bubble hole portion SB (this is a bubble hole of entrained air (bubbles created by a medicine) and the like having a relatively small cross-sectional dimension and a depth of the hole. The shading level (degree of whiteness) is high, and the cross-sectional dimensions of the black aggregate part and the deep bubble hole part DB (this is entrapped air (air bubbles taken in naturally)) are large. The shading level of the deep portion of the image becomes low (black). Since the illumination light spreads also to the bottom surface in the bubble hole, the bubble hole portion has a light and shade level almost equal to that of the cement paste.
(2) Second Step The second illumination unit is turned on, an image is taken, and the image is taken into the image processing device 50. The captured image at this time is shown in FIG. 5 (photograph). In addition, Table 1 shows the density level of the target portion of the image.
As apparent from FIG. 5 and Table 1, the concentration levels of the paste and the white aggregate portion are high, and the concentration levels of the bubble holes and the black aggregate portion are low. By irradiating the measurement target surface 11 with illumination light from a low angle, the illumination light does not reach the bottom surface in the bubble hole, and a shadow is formed in the hollow portion of the bubble hole. Lower.
(3) Third Step Both the first illumination unit and the second illumination unit are turned on, an image is taken, and the image is taken into the image processing apparatus 50. The captured image at this time is shown in FIG. 6 (photograph). Further, Table 2 shows the density level of the target portion of the image.
As is clear from FIG. 6 and Table 2, when both illumination means are turned on, the flat portion of the sample causes light diffusion, so-called halation phenomenon, and the concentration level becomes high. The same phenomenon occurs for the shallow bubble hole portion SB. As a result, the shallow bubble hole portion SB appears to be assimilated so as to have a concentration that cannot be recognized with respect to the surrounding white aggregate portion and cement paste portion. However, the deep bubble hole DB has a low concentration level because light does not rotate.
The above-described deep pore holes (13 or 14) are called entrapped air, and are irregular and relatively large bubbles that are potentially contained in concrete (not depending on the AE agent). is there. The cross-sectional shape is often different from the cross-sectional shape of the entrained air, which is substantially spherical, and is wider than the width of the narrow portion of the hole cross section (open end 13a or 14a) near the intersection of the hole and the plane portion of the measurement region. Often has a great depth. This type of hole is a hole in the depth direction where the longitudinal direction of the hole has a large angle with respect to the plane portion of the measurement region (in the case of FIG. 13), or a hole having a small angle along the plane portion. There is a case where the side surface of the perforation is broken in the plane portion (in the case of FIG. 14). Most of the bubble holes with a shallow depth are bubbles artificially mixed with a medicine (AE agent or the like) and are part of the substantially spherical bubble hole 12.
(4) Fourth Step In the image processing apparatus 50, the density of the captured image (captured image in the first step) only by the first illumination means and the captured image (captured image in the step 2) only by the second illumination means. Difference processing is performed to create a density difference image. A density difference image is shown in FIG. 7 (photograph). Further, Table 1 shows the result of the density difference process (only the attention part).
As a result of the concentration difference process, the concentration level of the shallow bubble hole portion SB is increased, and the concentration levels of the other portions are decreased. That is, as is apparent from FIG. 7, only the shallow bubble hole portion SB having a round shape can be recognized at a high concentration.
In the density difference process, 0 is designated when the subtraction result is less than 0.
(5) Fifth Step A binarization process is performed on the density difference image to create a binarized image. The result is shown in FIG. 8 (photograph).
Shallow bubble holes are “white” and the others are “black”. A white portion that looks like an “eighth-shape” indicates a state where adjacent substantially spherical bubble holes are partially connected.
It should be noted that in the fourth step, a threshold value for discrimination by binarization is set between the concentration of the shallow bubble hole portion SB and the concentration of the shallow bubble hole portion SB which becomes low concentration by the concentration difference process. In order to be able to do so, each illuminance in a plane portion where there is no hole in the measurement area by each of the first illumination means and the second illumination means is a relatively close numerical value (the density of the image captured at each illuminance). This means that the brightness, angle, shape, etc. of the first illumination means and the second illumination means must be adjusted so that the difference is sufficiently lower than the concentration of the shallow bubble hole portion SB.
Incidentally, Table 3 shows data obtained by comparing a specific black portion and a white portion with respect to the density of the captured image by each of the illumination by the first illumination means and the illumination by the second illumination means.
(6) Sixth Step A binarization process is performed on the image captured in the third step to create a binarized image. At that time, since the deep bubble hole portion DB becomes black, inversion processing is performed. The binarization threshold can be easily determined because there is a large concentration level difference between the deep bubble hole portion DB and the other portions (see Table 2). The result is shown in FIG. 9 (photograph). The deep bubble hole DB is “white” and the others are “black”.
(7) Seventh Step An exclusive OR operation is performed on the image obtained in the fifth step and the image obtained in the sixth step to create an exclusive OR image. An image obtained by reversing the result in black and white is shown in FIG. 10 (photograph).
By performing the exclusive logical ring operation, a mixed image (synthesized image) of the image of the shallow bubble hole portion SB and the image of the deep bubble hole portion DB is created.
(8) Eighth Step A feature amount extraction process of each bubble hole portion (white) is performed from the mixed image in the seventh step. An image showing one example is shown in FIG. 11 (photograph).
By executing the feature amount extraction process, the following data is calculated for the bubbles corresponding to each bubble hole.
Number of bubbles Center of gravity coordinates of each bubble Area of each bubble (number of pixels)
Perimeter circumference of each bubble Equivalent ellipse principal axis length of each bubble Equivalent ellipse minor axis length of each bubble Equivalent ellipse inclination angle of each bubble X minimum value of each bubble X maximum value of each bubble Y minimum value of each bubble Y Maximum value of circumscribed rectangle of each bubble The rectangle of circumscribed rectangle of each bubble

  The image processing device uses these data to write analysis data such as the amount of air present in the hardened concrete, bubble spacing coefficient, bubble specific surface area, bubble distribution, etc., together with the above data as necessary, Output as measurement results of bubbles in hardened concrete.

  In the above, when it is not necessary to detect deep bubble holes that are naturally generated due to various causes when manufacturing hardened concrete, the third step, the sixth step, and the seventh step are unnecessary. In the eighth step, The feature amount extraction process is executed on the binarized image obtained by performing the binarization process on the density difference image obtained in the fourth step.

In the present embodiment, the third illuminating means 43 which is a diffused light illuminating means is brought in as an illuminating means with respect to the first embodiment so as to serve as the illuminating means in the third step.
As shown in FIG. 2, one of the usages of the third illumination means 41 is a method of compensating for the shortage when the illuminance of the measurement area due to the illumination of both the first illumination means 41 and the second illumination means 42 is insufficient. is there.
As shown in FIG. 3, the third illumination means 43 has a third illumination means 43 only in place of the illumination of both the first illumination means 41 and the second illumination means 42 in the third step. This is a method of performing illumination for measurement (imaging) in steps. The advantage of this method is that depending on the type of hardened concrete, it may be assumed that the result of imaging in the third step cannot be obtained only by the combination of the first illumination means and the second illumination means. This is useful when special design must be performed for the shape, brightness, type of illumination light, etc. of the illumination means 43, and can extend the life of the illumination means.

  As the illumination means for imaging in the third step, it is possible to sufficiently increase the luminance of only the first illumination means 41 and perform illumination with sufficiently uniform illuminance on the measurement region. The block diagram of the arrangement of the components of the imaging system of the bubble measuring device for hardened concrete and the components from the camera to the image processing is the same as that shown in FIG. However, the first illumination means 41 is different in shape and illumination capability (luminance selection width) from the case of FIG.

  As mentioned above, although the content of this invention was demonstrated along the Example, it is not necessarily limited to the content of an Example, The content described below is also contained in this invention.

  Regarding the illumination means, in Examples 1, 2 and 3, the ring-shaped overall shape, the cross section is a quadrangle, and the surface in the measurement region direction of the ring (surface corresponding to the thick line) is the light emitting surface, There is no need to stick to this shape. The measurement area on the measurement target surface 11 is illuminated with an acceptable level of uniform illuminance, and the angle of illumination light that satisfies the principle of the present invention (elevation angle when viewing the illumination means from the measurement area) and light emission Any shape can be used as long as the size and angle of the surface and the brightness are achieved. For example, each illumination unit may be configured by a set of discrete small illumination units.

The first illumination means 41, the second illumination means 42, and the third illumination means 43 have been diffused light illumination means. However, as long as the reflected light does not enter the digital camera 30 and the imaging is not performed normally. It is not necessary to be a diffused light illumination means. In particular, in the second illuminating means that irradiates illumination light from a low angle with respect to the measurement region, the necessity of diffused light is low.
As a method for preventing the specularly reflected light from entering the digital camera, there is a method of disposing a polarizing filter in front of the digital camera.

  Although it has been described in the embodiment that the stage is moved in the direction of the orthogonal XY coordinates, it is not always necessary, and a stage moving method that can set a desired position on the measurement target surface 11 as a measurement region. Any method can be used. For example, a moving method using oblique coordinates, a method using rotation and radial movement, and the like can be employed.

  The method and the bubble measuring device for the hardened concrete of the present invention described above is to perform the recognition extraction of the bubble hole by image processing of the computer, it can be excluded that the subjectivity of the measurement operator extends to the measurement operation, Measurement stability and reliability can be ensured.

FIG. 2 is a block diagram showing the arrangement of components of an imaging system of a bubble measuring apparatus for hardened concrete in Example 1 of the present invention and components of a part from a camera to image processing. The other arrangement (addition of the 3rd illumination means 43) of the component of the imaging system of the bubble measuring apparatus of hardened concrete of this invention and the component of the part from a camera to image processing are shown with the block diagram. Still another arrangement of the components of the imaging system of the bubble measuring device for hardened concrete of the present invention (the shape of the third illumination means 43 is different) and the components from the camera to the image processing are shown in a block diagram It is. It is a photograph which shows the image taken in only by the 1st illumination means at the 1st step. It is a photograph which shows the image taken in only by the 2nd illumination means in the 2nd step. It is a photograph which shows the image taken in by making all the 1st illumination means, the 2nd illumination means, and the 3rd illumination means light in a 3rd step. A photograph showing a density difference image obtained by performing density difference processing on a captured image (captured image in the first step) only by the first illumination means and a captured image only by the second illumination means (captured image in the step 2). is there. It is a photograph which shows the binarized image which performed the binarization process with respect to the density | concentration difference image at the 5th step. It is a photograph which shows the binarized image which performed the binarization process with respect to the image taken in by the 7th step at the 3rd step. In the 8th step, an exclusive OR operation is performed on the image obtained in the 6th step and the image obtained in the 7th step to create an exclusive OR image, and this result is converted to black and white. It is the photograph which shows an image. It is a photograph which shows an example of the image which performed the feature-value extraction process of each bubble hole part (white) from the mixed image of an 8th step at the 9th step. It is the figure which showed the example (substantially spherical) of the bubble hole which has appeared on the measurement object surface. It is the figure which showed the other example (hole deep in the direction orthogonal to a measurement object surface) of the bubble hole which has appeared on the measurement object surface. It is the figure which showed the further another example (hole long along a measurement object surface) of the bubble hole which has appeared on the measurement object surface.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Hardened concrete sample 11 Measurement object surface 12 Spherical bubble hole 12a Open end 13 Deep bubble hole 13a Open end 14 Deep bubble hole 14a-1 Open end 14a-2 Open end 20 Stage 30 Digital camera 32 Digital camera optical axis 41 First illumination means 42 Second illumination means 43 Third illumination means 50 Image processing apparatus

Claims (12)

A measurement target surface is set using a part of the hardened concrete containing air bubbles, and the shape of the opening end of the hole surrounding the air bubbles opening on the measurement target surface is measured to measure the air bubbles contained in the hardened concrete. A way to do,
With a digital camera by illumination of the first illumination means arranged facing the measurement area of the measurement target surface so that the inner surface of the hole surrounding the substantially spherical bubble appearing on the measurement target surface is not shaded The first captured image of the measurement area that has been imaged and the inner surface of a hole that encloses a substantially spherical bubble are arranged opposite to the measurement area to illuminate so as to be shaded except in the vicinity of the opening end. A first bubble image that is a density difference image created by density difference processing between the second captured image of the measurement region captured by the digital camera by illumination of two illumination means;
In the captured image, a second type of bubble having a high density level in both the inner surface of the substantially spherical bubble hole and the planar portion in the measurement region, the cross-sectional shape being irregular, and a depth larger than the width of the narrow portion of the entrance. With respect to the third captured image of the measurement region captured by illumination from the illumination means such that the density level of the image of the hole is low and these high and low density levels can be easily distinguished, the second image By performing the feature amount extraction process of the image of the opening end of the hole that wraps the bubbles appearing in the measurement region using the second bubble image subjected to the process of extracting the image of the bubble hole of the form, A method for measuring bubbles in hardened concrete, comprising measuring bubbles contained in hardened concrete. A binarization process is performed on each of the first bubble image and the second bubble image to form a first binarized image and a second binarized image, respectively, and the first binarized image and the second binarized image. by combining the binarized image as a single synthetic bubble image, and performs the feature amount extraction processing of the opening end of the hole surrounding the bubbles against the synthetic bubble image appearing in the measurement region according Item 2. A method for measuring bubbles in hardened concrete according to Item 1 . The first binarized image and the second binarized image are obtained by performing a logical calculation by exclusive OR between the first binarized image and the black and white inverted image of the second binarized image. The method for measuring bubbles in hardened concrete according to claim 2 , wherein: The curing unit according to any one of claims 1 to 3 , wherein the illumination unit for capturing the third captured image is an illumination unit that irradiates diffused light from a plurality of angles to the measurement region. Bubble measurement method for concrete. Said third illumination means when capturing an captured image, according to any of claims 1 to 3, characterized in that a plurality of diffuse illumination means including said first illuminating means and the second illumination means Method for measuring bubbles in hardened concrete. Claim 1 where the illuminating means when imaging the third captured image, or the third illuminating means is provided for imaging of the third captured image, or, characterized in that either of said first illuminating means To 3. The method for measuring bubbles in hardened concrete according to any one of items 1 to 3 . A measurement target surface is set using a part of the hardened concrete containing air bubbles, and the shape of the opening end of the hole surrounding the air bubbles opening on the measurement target surface is measured to measure the air bubbles contained in the hardened concrete. A device for performing
A digital camera for imaging the measurement area of the measurement target surface;
An image processing apparatus that performs image processing on an image captured by the digital camera;
A first illuminating means arranged to face the measurement region so as to illuminate so that an inner surface of the hole surrounding the substantially spherical bubble appearing in the measurement region is not shaded; and a hole enclosing the substantially spherical bubble At least a second illuminating means arranged as opposed to the measurement region to illuminate the inner surface in the shade except for the vicinity of the opening end, as an illuminating means,
In the image processing apparatus, a first captured image of the measurement region captured by the digital camera by illumination of the first illumination unit and a first of the measurement region captured by the digital camera by illumination of the second illumination unit. A first bubble image that is a density difference image created by density difference processing between two captured images;
In the captured image, a second type of bubble having a high density level in both the inner surface of the substantially spherical bubble hole and the planar portion in the measurement region, the cross-sectional shape being irregular, and a depth larger than the width of the narrow portion of the entrance. With respect to the third captured image of the measurement region captured by illumination from the illumination means such that the density level of the image of the hole is low and these high and low density levels can be easily distinguished, the second image By performing the feature amount extraction process of the image of the opening end of the hole that wraps the bubbles appearing in the measurement region using the second bubble image subjected to the process of extracting the image of the bubble hole of the form, A device for measuring bubbles in hardened concrete, which measures bubbles contained in hardened concrete. A binarization process is performed on each of the first bubble image and the second bubble image to form a first binarized image and a second binarized image, respectively, and the first binarized image and the second binarized image. by combining the binarized image as a single synthetic bubble image, and performs the feature amount extraction processing of the opening end of the hole surrounding the bubbles against the synthetic bubble image appearing in the measurement region according Item 8. The bubble measuring device for hardened concrete according to Item 7 . The first binarized image and the second binarized image are obtained by performing a logical calculation by exclusive OR between the first binarized image and the black and white inverted image of the second binarized image. The air bubble measuring device for hardened concrete according to claim 8 , wherein: The curing unit according to any one of claims 7 to 9 , wherein the illuminating unit for capturing the third captured image is an illuminating unit that irradiates diffused light from a plurality of angles to the measurement region. A bubble measuring device for concrete. 10. The lighting device according to claim 7 , wherein the lighting unit for capturing the third captured image is a plurality of lighting units including both the first lighting unit and the second lighting unit. 11 . Air bubble measurement device for hardened concrete. 7. the illuminating means when imaging the third captured image, or the third illuminating means is provided for imaging of the third captured image, or, characterized in that either of said first illuminating means To 9 for measuring a bubble of hardened concrete.