JP2024173781A - Measurement system and program - Google Patents

Abstract

To provide a measuring system and a measuring program capable of improving measurement sensitivity for a density gradient of a measuring object.SOLUTION: A measuring system includes: an input part 3 to which a condition for imaging a measuring object is input; a first image generation part 411 which generates a background image with a pattern according to the condition input to the input part 3; a display 5 which displays the background image generated by the first image generation part 411; an imaging part 6 which images the background image displayed by the display 5 and a measuring object according to the condition; and a second image generation part 412 which generates a density gradient image showing a density gradient on the basis of the picked-up image imaged by the imaging part 6.SELECTED DRAWING: Figure 2

Description

The present invention relates to a measurement system and a measurement program that visualizes the density gradient of an object to be measured.

Patent Document 1 discloses a fluid density gradient detection system that uses the background oriented Schlieren method (hereinafter also referred to as the "BOS method"). Patent Document 1 describes how the density gradient of airflow can be visualized with high sensitivity using a general-purpose camera or an existing camera.

However, depending on the conditions under which the imaging unit, such as a general-purpose camera or an existing camera, captures the background image, the pattern of the background image, or the shape of the object to be measured, it may be difficult to improve the measurement sensitivity of the density gradient of the object to be measured or to reduce the noise that appears in the image showing the density gradient.

JP 2022-184123 A

The present invention was made in consideration of the above circumstances, and provides a measurement system and a measurement program that can improve the measurement sensitivity of the density gradient of a measurement object.

The above problem is solved by the measurement system of the present invention, which is a measurement system for visualizing the density gradient of a measurement object, and is characterized by comprising an input unit to which conditions for imaging the measurement object are input, a first image generation unit that generates a background image having a pattern according to the conditions input to the input unit, a display unit that displays the background image generated by the first image generation unit, an imaging unit that images the background image displayed by the display unit and the measurement object under the above conditions, and a second image generation unit that generates a density gradient image showing the density gradient based on the image captured by the imaging unit.

According to the measurement system of the present invention, the first image generation unit generates a background image having a pattern according to the imaging conditions input to the input unit. Therefore, the first image generation unit can generate a background image having a more appropriate pattern according to the imaging conditions input to the input unit. Furthermore, the imaging unit captures the background image having the more appropriate pattern generated by the first image generation unit and the measurement object under the imaging conditions input to the input unit. Then, the second image generation unit generates a density gradient image showing the density gradient of the measurement object based on the captured image captured by the imaging unit. This allows the measurement system of the present invention to improve the measurement sensitivity of the density gradient of the measurement object.

In the measurement system according to the present invention, the pattern preferably has a regularity.

The measurement system according to the present invention can reduce non-uniformity in measurement sensitivity due to the influence of random patterns, and improve the measurement sensitivity of density gradients approximately uniformly in all directions, compared to when a background image having a random pattern is displayed.

In the measurement system according to the present invention, preferably, the imaging unit has an imaging element, and the pattern is a striped pattern having light and dark areas arranged in a direction inclined with respect to the arrangement direction of the pixels of the imaging element.

The measurement system according to the present invention can improve the measurement sensitivity of density gradients in all directions, regardless of the direction of the density gradient of the object being measured.

In the measurement system according to the present invention, the stripe pattern is preferably a black and white binary stripe pattern.

The measurement system according to the present invention can improve the measurement sensitivity of the density gradient of the object to be measured by increasing the contrast between the light and dark areas of the striped pattern of the background image.

In the measurement system according to the present invention, preferably, each of the bright and dark areas has a width of 2 pixels or more and 10 pixels or less on the imaging element.

The measurement system according to the present invention can improve the measurement sensitivity of the density gradient of the object to be measured and reduce noise.

In the measurement system according to the present invention, the angle of the direction in which the bright and dark areas are inclined relative to the arrangement direction is preferably 25 degrees or more and 65 degrees or less.

The measurement system according to the present invention can further improve the measurement sensitivity of density gradients in all directions, regardless of the direction of the density gradient of the object being measured.

In the measurement system according to the present invention, preferably, the angle of the direction in which the bright and dark areas are inclined with respect to the arrangement direction is 45 degrees.

The measurement system according to the present invention can further improve the measurement sensitivity of density gradients in all directions, regardless of the direction of the density gradient of the object being measured.

In the measurement system according to the present invention, preferably, the display unit displays the background image by emitting or reflecting visible light, and the measurement object is a film or plate that transmits the visible light.

The measurement system according to the present invention can improve the measurement sensitivity of the density gradient of films and other membranes that transmit visible light, and plates such as glass plates.

In the measurement system according to the present invention, preferably, the display unit displays the background image by emitting or reflecting invisible light, and the measurement object transmits the invisible light but not visible light.

According to the measurement system of the present invention, even if the object to be measured does not transmit visible light, the display unit emits or reflects invisible light to display a background image, thereby improving the measurement sensitivity of the density gradient of the object to be measured that transmits invisible light.

The above problem is solved by the measurement system of the present invention, which is a measurement system for visualizing the density gradient of a measurement object, and is characterized by comprising a display unit that displays a background image having a pattern, an imaging unit that images the background image displayed by the display unit and a film or plate as the measurement object, and an image generation unit that generates a density gradient image showing the density gradient based on the image captured by the imaging unit.

The measurement system according to the present invention can improve the measurement sensitivity of the density gradient of the object to be measured and reduce noise, even if the object to be measured is a film or plate with a relatively thin thickness.

The above problem is solved by the measurement program of the present invention, which is executed by a computer of a measurement system that visualizes the density gradient of a measurement object, and causes the computer to execute the steps of acquiring conditions for imaging the measurement object, generating a background image having a pattern according to the acquired conditions, displaying the generated background image, imaging the displayed background image and the measurement object under the conditions, and generating a density gradient image showing the density gradient based on the captured image.

According to the measurement program of the present invention, a background image having a pattern is generated according to the acquired imaging conditions. Therefore, a background image having a more appropriate pattern can be generated according to the acquired imaging conditions. Furthermore, the generated background image having the more appropriate pattern and the measurement object are imaged under the acquired imaging conditions. Then, a density gradient image showing the density gradient of the measurement object is generated based on the captured image. As a result, the measurement program of the present invention can improve the measurement sensitivity of the density gradient of the measurement object.

The present invention provides a measurement system and a measurement program that can improve the measurement sensitivity of the density gradient of a measurement object.

FIG. 1 is a schematic diagram illustrating a measurement system according to an embodiment of the present invention. FIG. 2 is a block diagram showing a computer provided in the measurement system of the present embodiment. 10 is a flowchart showing a specific example of processing executed by the measurement system according to the present embodiment. 13 is a first specific example of a pattern of a background image according to the present embodiment. 13 is a second specific example of a pattern of a background image according to the present embodiment. 5 is a diagram illustrating an example of a density gradient image generated when the pattern of the background image is the striped pattern illustrated in FIG. 4 . 5 is a diagram illustrating an example of a density gradient image generated when the pattern of the background image is the striped pattern illustrated in FIG. 4 . 6 is a diagram illustrating an example of a density gradient image generated when the pattern of the background image is the checkered pattern illustrated in FIG. 5 . FIG. 13 is a diagram illustrating an example of a density gradient image generated when the pattern of a background image is a random pattern.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.
The embodiments described below are preferred specific examples of the present invention, and therefore various technically preferable limitations are applied to them, but the scope of the present invention is not limited to these aspects unless otherwise specified in the following description to the effect that the present invention is limited to them. In addition, in each drawing, similar components are given the same reference numerals, and detailed descriptions thereof are omitted as appropriate.

FIG. 1 is a schematic diagram illustrating a measurement system according to an embodiment of the present invention.
FIG. 2 is a block diagram showing a computer provided in the measurement system of this embodiment.

The measurement system 2 according to this embodiment is a system that visualizes the density gradient of the measurement object 9 using the background oriented Schlieren method (hereinafter also referred to as the "BOS method"). The measurement object 9 is not limited to a fluid (i.e., gas and liquid) and may be a solid. The measurement object 9 may be an object that transmits visible light, or an object that does not transmit visible light but transmits invisible light. Examples of the measurement object 9 include a film or plate that transmits visible light. Examples of the measurement object 9 include a film or plate that does not transmit visible light but transmits invisible light. Examples of the measurement object 9 include coffee or soy sauce that does not transmit visible light but transmits invisible light. However, the measurement object 9 is not limited to these objects.

As shown in FIG. 1, the measurement system 2 of this embodiment includes an input unit 3, a computer 4, a first display unit 5, and an imaging unit 6. The measurement system 2 may further include a second display unit 7.

Conditions for capturing an image of the measurement target 9 (hereinafter, for convenience of explanation, referred to as "imaging conditions") are input to the input unit 3. Examples of imaging conditions include the pixel size (i.e., pixel size) and number of pixels (i.e., pixel count) of the imaging element (i.e., image sensor) of the imaging unit 6, the focal length of the lens of the imaging unit 6, the angle of view of the lens of the imaging unit 6, and the distance D between the imaging unit 6 and the first display unit 5. Examples of the input unit 3 include a keyboard and a mouse.

The input unit 3 may be provided integrally with the second display unit 7. That is, the input unit 3 may be provided integrally with the second display unit 7 as a display including a touch panel capable of detecting, for example, contact with the subject's finger. In this case, for example, the subject can input imaging conditions by operating the second display unit 7 provided integrally with the input unit 3. The imaging conditions input to the input unit 3 are transmitted to the computer 4.

2, the computer 4 has a control unit 41, a transmission/reception unit 42, and a storage unit 43, and receives the imaging conditions input to the input unit 3 via the transmission/reception unit 42. The computer 4 also reads out a program 431 stored in the storage unit 43 to execute various calculations and processes. The "computer" here is not limited to a personal computer, but also includes an arithmetic processing device, a microcomputer, etc. included in an information processing device, and is a general term for a device or apparatus that can realize the functions of the present invention by a program.

The program 431 of this embodiment is an example of the "measurement program" of the present invention. The program 431 includes an image recognition program for recognizing an image, an image generation program for generating an image, and a sequence program for causing the imaging unit 6 to capture the image displayed by the first display unit 5 and the measurement target 9 under predetermined imaging conditions (i.e., the imaging conditions received from the input unit 3 via the transmission/reception unit 42). Note that the program 431 is not limited to being stored in the storage unit 43, and may be stored in advance in a computer-readable storage medium and distributed, or may be downloaded to the computer 4 via a network.

The control unit 41 is, for example, a CPU (central processing unit) and reads out a program 431 stored in the memory unit 43 to execute various calculations and processes. The control unit 41 has a first image generating unit 411 and a second image generating unit 412. The first image generating unit 411 and the second image generating unit 412 are realized by the computer 4 executing the program 431 stored in the memory unit 43. Note that the first image generating unit 411 and the second image generating unit 412 may be realized by hardware or a combination of hardware and software.

The first image generating unit 411 generates a background image having a pattern according to the imaging conditions input to the input unit 3. For example, the background image generated by the first image generating unit 411 is transmitted to the first display unit 5 via the transmitting/receiving unit 42 and displayed thereon. In this case, the first display unit 5 is a display such as a liquid crystal panel or an organic EL (Electro Luminescence) panel, and displays the background image received from the computer 4.

Alternatively, the first display unit 5 is a screen, a wall, or the like, and displays a background image projected by a projector. In this case, the background image generated by the first image generation unit 411 is transmitted to the projector via the transmission/reception unit 42. Alternatively, the background image generated by the first image generation unit 411 may be stored in a portable storage medium and input to the projector by the storage medium. When the first display unit 5 displays a background image projected by a projector, the first display unit 5 includes a medium (such as a screen or a wall) that displays the background image projected by the projector, and a device (such as a projector) that projects the background image.

Alternatively, the first display unit 5 may be a device (such as a projector) that projects a background image. In other words, the first display unit 5 does not necessarily have a medium (such as a screen or wall) for displaying the background image projected by the projector, and may be only a device that projects the background image. In this case, for example, by matching the imaging position of the background image projected by a device such as a projector with the focal position of the imaging unit 6, the imaging unit 6 can capture the background image displayed by the first display unit 5.

Also, for example, the background image generated by the first image generation unit 411 is printed on a portable medium such as paper. In this case, the first display unit 5 is a screen, a wall, or the like, and displays the background image by attaching the medium on which the background image is printed. When the first display unit 5 displays a background image printed on a medium such as paper, the first display unit 5 includes the medium (e.g., paper) on which the background image is printed, and the screen, wall, or the like on which the medium on which the background image is printed is attached.

Also, for example, the background image generated by the first image generation unit 411 is printed on a portable medium such as an OHP (overhead projector) sheet (i.e., transparency). In this case, the first display unit 5 is a screen, a wall, or the like, and displays the background image projected by the OHP. When the first display unit 5 displays the background image projected by the OHP, the first display unit 5 includes a medium on which the background image is printed (e.g., transparency), an OHP, and a medium (such as a screen or wall) that displays the background image projected by the OHP.

Alternatively, the first display unit 5 may be an overhead projector (OHP) sheet (i.e., transparency) and an OHP. That is, the first display unit 5 does not necessarily have a medium (such as a screen or wall) for displaying the background image projected by the OHP, and may be only an OHP sheet on which the background image is printed and an OHP. In this case, for example, by matching the imaging position of the background image projected by the OHP with the focal position of the imaging unit 6, the imaging unit 6 can capture the background image displayed by the first display unit 5.

In this way, the first display unit 5 displays the background image generated by the first image generation unit 411 by emitting or reflecting light rays. In this specification, "emitting light rays" does not only mean that a display such as a liquid crystal panel or an organic EL panel emits light rays, as described above, but also includes an OHP emitting light rays and the light rays passing through an OHP sheet. Also, in this specification, "reflecting light rays" does not only mean that a medium such as a screen or a wall reflects light rays, as described above, but also includes a medium such as paper on which a background image is printed reflecting light rays.

The first display unit 5 may display the background image generated by the first image generating unit 411 by emitting or reflecting visible light, or may display the background image generated by the first image generating unit 411 by emitting or reflecting invisible light. When the first display unit 5 displays the background image by emitting or reflecting visible light, the measurement object 9 is an object that transmits visible light, such as a film and a plate that transmits visible light. When the first display unit 5 displays the background image by emitting or reflecting invisible light, the measurement object 9 is an object that does not transmit visible light but transmits invisible light, such as a film and a plate that does not transmit visible light but transmits invisible light. Alternatively, when the first display unit 5 displays the background image by emitting or reflecting invisible light, the measurement object 9 is, for example, coffee and soy sauce that do not transmit visible light but transmit invisible light.
An example of a background image pattern generated by the first image generating unit 411 will be described later.

The second image generating unit 412 generates a density gradient image showing the density gradient of the measurement object 9 based on the captured image captured by the imaging unit 6. The second image generating unit 412 uses a known analysis algorithm when generating the density gradient image. The analysis algorithm used by the second image generating unit 412 is stored in the storage unit 43. In addition, the second image generating unit 412 transmits the generated density gradient image to the second display unit 7 via the transmission/reception unit 42, and executes a process of displaying the density gradient image on the second display unit 7.

The storage unit 43 stores the background image generated by the first image generation unit 411, the captured image captured by the imaging unit 6, the density gradient image generated by the second image generation unit 412, the program 431 executed by the computer 4, and the analysis algorithm used by the second image generation unit 412. Examples of the storage unit 43 include a semiconductor memory or a hard disk drive (HDD: Hard Disk Drive) built into the computer 4. Alternatively, examples of the storage unit 43 include various storage media and storage devices connectable to the computer 4, such as a CD (Compact Disc), a DVD (Digital Versatile Disc), a RAM (Random access memory), a ROM (Read only memory), a hard disk, and a memory card.

The imaging unit 6 is electrically connected to the computer 4. Based on a control signal received from the computer 4, the imaging unit 6 captures the background image displayed by the first display unit 5 and the measurement target 9 under the imaging conditions input to the input unit 3. The imaging unit 6 is a camera having an image sensor such as a CCD (Charge Coupled Device) or a CMOS (Complementary Metal Oxide Semiconductor), and transmits the captured image data to the computer 4 via the transmission/reception unit 42. The image data (i.e., the captured image) captured by the imaging unit 6 and transmitted to the computer 4 is stored in the memory unit 43.

The second display unit 7 displays the density gradient image generated by the second image generating unit 412 as the analysis result. Examples of the second display unit 7 include displays such as a liquid crystal panel and an organic EL panel. As described above, the second display unit 7 may be provided integrally with the input unit 3 as a display including a touch panel capable of detecting the touch of the finger of the person performing the measurement, for example.

Here, depending on the conditions under which the imaging unit captures the background image or the pattern of the background image, it may be difficult to improve the measurement sensitivity of the density gradient of the object to be measured or to reduce noise that appears in the density gradient image.

In contrast, in the measurement system 2 according to this embodiment, the first image generation unit 411 generates a background image having a pattern according to the imaging conditions input to the input unit 3. Therefore, the first image generation unit 411 can generate a background image having a more appropriate pattern according to the imaging conditions input to the input unit 3. Furthermore, the imaging unit 6 captures the background image having a more appropriate pattern generated by the first image generation unit 411 and the measurement object 9 under the imaging conditions input to the input unit 3. Then, the second image generation unit 412 generates a density gradient image showing the density gradient of the measurement object 9 based on the captured image captured by the imaging unit 6. As a result, the measurement system 2 according to this embodiment can improve the measurement sensitivity of the density gradient of the measurement object 9.

Next, a specific example of the processing executed by the measurement system 2 according to this embodiment will be described with reference to the drawings. The specific example of the processing described below is an example of the processing that the measurement program according to this embodiment causes the computer 4 to execute.

FIG. 3 is a flowchart showing a specific example of the process executed by the measurement system according to the present embodiment.
FIG. 4 shows a first specific example of a background image pattern according to this embodiment.
FIG. 5 shows a second specific example of a background image pattern according to this embodiment.

First, in step S1, the conditions for capturing an image of the measurement target 9 (i.e., the imaging conditions) are input to the input unit 3. For example, the person measuring inputs the imaging conditions by operating the input unit 3. As described above with reference to Figs. 1 and 2, the imaging conditions input to the input unit 3 include, for example, the pixel size and number of pixels of the imaging element of the imaging unit 6, the focal length of the lens of the imaging unit 6, the angle of view of the lens of the imaging unit 6, and the distance D between the imaging unit 6 and the first display unit 5 (see Fig. 1).

Next, in step S2, the first image generating unit 411 generates a background image having a pattern according to the imaging conditions input to the input unit 3. As shown in FIG. 4, the pattern of the background image generated by the first image generating unit 411 is, for example, regular diagonal lines. Specifically, the pattern of the background image shown in FIG. 4 is a striped pattern having light areas 44 and dark areas 45 arranged in a direction inclined with respect to the arrangement direction of the pixels of the imaging element (i.e., the image sensor) of the imaging unit 6. For example, the light areas 44 are white and the dark areas 45 are black. In this case, the pattern of the background image shown in FIG. 4 is a black and white binary striped pattern.

Each of the light and dark areas 44 and 45 in the background image pattern, i.e., the striped pattern, generated by the first image generation unit 411 has a width of 2 pixels or more and 10 pixels or less on the imaging element of the imaging unit 6. It is more preferable that each of the light and dark areas 44 and 45 in the striped pattern of the background image has a width of 2 pixels or more and 6 pixels or less on the imaging element of the imaging unit 6. Each scale shown in FIG. 4 represents one pixel on the imaging element of the imaging unit 6. That is, in the example shown in FIG. 4, each of the light and dark areas 44 and 45 in the striped pattern has a width of 4 pixels on the imaging element of the imaging unit 6.

The angle at which the light and dark areas 44 and 45 in the background image pattern, i.e., the striped pattern, generated by the first image generation unit 411 are inclined relative to the pixel arrangement direction of the image sensor of the image capture unit 6 is 25 degrees or more and 65 degrees or less. In the example shown in FIG. 4, the angle at which the light and dark areas 44 and 45 in the background image pattern, i.e., the striped pattern, are inclined relative to the pixel arrangement direction of the image sensor of the image capture unit 6 is 45 degrees.

Alternatively, as shown in FIG. 5, the pattern of the background image generated by the first image generation unit 411 is, for example, a checkered pattern with regularity. In this specification, a "checkered pattern" includes a striped pattern having light areas 44 and dark areas 45 arranged in a direction inclined with respect to the direction in which the pixels of the image sensor of the imaging unit 6 are arranged. For example, the light areas 44 are white and the dark areas 45 are black. In this case, the pattern of the background image shown in FIG. 5 is a black and white binary striped pattern.

Each of the light and dark areas 44 and 45 in the checkered pattern of the background image generated by the first image generation unit 411 has a width of 2 pixels or more and 10 pixels or less on the imaging element of the imaging unit 6. It is more preferable that each of the light and dark areas 44 and 45 in the checkered pattern of the background image has a width of 2 pixels or more and 6 pixels or less on the imaging element of the imaging unit 6. Each scale shown in FIG. 5 represents one pixel on the imaging element of the imaging unit 6. That is, in the example shown in FIG. 5, each of the light and dark areas 44 and 45 in the checkered pattern has a width of 4 pixels on the imaging element of the imaging unit 6.

In the example shown in FIG. 5, the angle at which the light areas 44 and dark areas 45 in the checkerboard pattern of the background image generated by the first image generation unit 411 are tilted relative to the pixel arrangement direction of the image sensor of the image capture unit 6 is 45 degrees.

In the striped pattern shown in FIG. 4, when viewed along a first array direction (e.g., either the vertical or horizontal direction) of the pixels of the imaging element of the imaging unit 6, there are bright portions 44 and dark portions 45 that are shifted by one image or more in the second array direction (e.g., the other of the vertical and horizontal directions). On the other hand, in the checkered pattern shown in FIG. 5, when viewed along the first array direction of the pixels of the imaging element of the imaging unit 6, there are no bright portions 44 and no dark portions 45 that are shifted by one image or more in the second array direction. That is, in the checkered pattern shown in FIG. 5, when viewed along the first array direction of the pixels of the imaging element of the imaging unit 6, the pixels of the bright portions 44 and the dark portions 45 match in the second array direction.

In step S3 following step S2, the first display unit 5 displays the background image generated by the first image generation unit 411. The manner in which the first display unit 5 displays the background image is as described above with reference to Figs. 1 and 2. Next, in step S4, the imaging unit 6 captures the background image displayed by the first display unit 5 and the measurement target 9 under the imaging conditions input to the input unit 3 based on the control signal received from the computer 4.

Next, in step S5, the second image generating unit 412 generates a density gradient image showing the density gradient of the measurement object 9 based on the captured image captured by the imaging unit 6. The second image generating unit 412 uses a known analysis algorithm when generating the density gradient image. Next, in step S6, the second display unit 7 displays the density gradient image generated by the second image generating unit 412 (i.e., an image showing the density gradient of the measurement object 9) as the analysis result.

In this specific example, as shown in Figures 4 and 5, the pattern of the background image has regularity, so compared to the case where a background image having a random pattern is displayed by the first display unit 5, it is possible to suppress non-uniformity in measurement sensitivity due to the influence of the random pattern and improve the measurement sensitivity of the density gradient approximately uniformly in all directions.

The background image pattern is a striped pattern having light areas 44 and dark areas 45 arranged in a direction inclined relative to the direction in which the pixels of the imaging element of the imaging unit 6 are arranged. Therefore, it is possible to improve the measurement sensitivity of the density gradient in all directions, regardless of the direction of the density gradient of the object to be measured. In addition, when the background image pattern is a binary black and white striped pattern, it is possible to improve the measurement sensitivity of the density gradient of the object to be measured by increasing the contrast between the light areas 44 and dark areas 45 of the striped pattern.

In addition, since each of the light and dark areas 44 and 45 of the striped pattern has a width of 2 pixels or more and 10 pixels or less in the image sensor of the image capture unit 6, the measurement sensitivity of the density gradient of the measurement object 9 can be improved and noise can be reduced. Details of this will be described later with reference to Figures 6 to 9.

In addition, the angle of the light and dark areas 44 and 45 in the background image pattern with respect to the direction in which the pixels of the image sensor of the image capture unit 6 are arranged is 25 degrees or more and 65 degrees or less (45 degrees in the example of Figures 4 and 5), so that the measurement sensitivity of the density gradient in all directions can be further improved regardless of the direction of the density gradient of the measurement object 9. Details of this will be described later with reference to Figures 6 to 9.

Next, an example of a density gradient image acquired by the present inventor using the measurement system 2 and the measurement program according to this embodiment will be described with reference to the drawings.
6 and 7 are diagrams showing an example of a density gradient image generated when the background image pattern is the striped pattern shown in FIG.
FIG. 8 is a diagram showing an example of a density gradient image generated when the pattern of the background image is the checkered pattern exemplified in FIG.
FIG. 9 is a diagram showing an example of a density gradient image generated when the pattern of the background image is a random pattern.

Note that Figs. 6(a) and 7(a) are diagrams showing an example of a density gradient image generated by the second image generating unit 412 when the imaging unit 6 captures only the background image displayed by the first display unit 5. Figs. 6(b), 7(b), 8, and 9 are diagrams showing an example of a density gradient image generated by the second image generating unit 412 when the imaging unit 6 captures the background image displayed by the first display unit 5 and the "air around a person's hand" as the measurement object 9.

The inventor obtained a density gradient image using the measurement system 2 and measurement program according to this embodiment. The imaging conditions input by the inventor to the input unit 3 are as follows. That is, the imaging unit 6 is a high-resolution CMOS camera. The number of pixels of the imaging element of the imaging unit 6 is 5 million. The frame rate of the imaging unit 6 is 30 fps. The first display unit 5 is a liquid crystal panel. That is, the liquid crystal panel as the first display unit 5 displays the background image generated by the first image generation unit 411.

9, when the pattern of the background image displayed by the first display unit 5 is a random pattern, noise 91 appears in the air around the person's hand in the density gradient image (i.e., the measurement object 9). In addition, the measurement sensitivity of the density gradient of the measurement object 9 (i.e., the air around the person's hand) is relatively low. In the density gradient image shown in FIG. 9, the random pattern of the background image is a pattern in which the first image generating unit 411 randomly selects pixels in the light (white) and dark (black) areas so that the ratio of each of the pixels in the light (white) and dark (black) areas is 50%. Therefore, the range of existence of the light areas and the range of existence of the dark areas are not uniform in the background image, and the measurement sensitivity of the density gradient of the measurement object 9 is non-uniform, as shown in FIG. 9.

In contrast, as shown in Figs. 6(a) and 7(a), when the pattern of the background image displayed by the first display unit 5 is the striped pattern illustrated in Fig. 4, noise does not appear in the density gradient image. Also, as shown in Figs. 6(b) and 7(b), when the pattern of the background image displayed by the first display unit 5 is the striped pattern illustrated in Fig. 4, noise does not appear in the air around the person's hand in the density gradient image (i.e., the measurement object 9). Furthermore, as shown in Figs. 6(b) and 7(b), when the pattern of the background image displayed by the first display unit 5 is the striped pattern illustrated in Fig. 4, the measurement sensitivity of the density gradient of the measurement object 9 (i.e., the air around the person's hand) is relatively high.

In the density gradient images shown in Figs. 6(a) to 7(b), the pattern of the background image displayed by the first display unit 5 is a binary black and white striped pattern. The angle of the direction in which the light and dark areas 44 and 45 in the striped pattern are inclined with respect to the pixel arrangement direction of the imaging element of the imaging unit 6 is 45 degrees. In the density gradient images shown in Figs. 6(a) to 6(b), each of the light and dark areas 44 and 45 in the striped pattern of the background image has a width of 5 pixels in the imaging element of the imaging unit 6. In the density gradient images shown in Figs. 7(a) to 7(b), each of the light and dark areas 44 and 45 in the striped pattern of the background image has a width of 3 pixels in the imaging element of the imaging unit 6.

As shown in FIG. 8, when the pattern of the background image displayed by the first display unit 5 is the checkered pattern illustrated in FIG. 5, noise does not appear in the air around the person's hand in the density gradient image (i.e., the measurement object 9). As shown in FIG. 8, when the pattern of the background image displayed by the first display unit 5 is the checkered pattern illustrated in FIG. 5, the measurement sensitivity of the density gradient of the measurement object 9 (i.e., the air around the person's hand) is relatively high.

In the density gradient image shown in FIG. 8, the pattern of the background image displayed by the first display unit 5 is a binary black and white checkered pattern. In the density gradient image shown in FIG. 8, each of the light areas 44 and dark areas 45 in the checkered pattern of the background image has a width of four pixels in the imaging element of the imaging unit 6.

The above describes an embodiment of the present invention. However, the present invention is not limited to the above embodiment, and various modifications can be made without departing from the scope of the claims. The configurations of the above embodiment can be partially omitted or arbitrarily combined in a different way than described above.

2: Measurement system, 3: Input section, 4: Computer, 5: First display section, 6: Imaging section, 7: Second display section, 9: Measurement object, 41: Control section, 42: Transmitting/receiving section, 43: Memory section, 44: Bright area, 45: Dark area, 91: Noise, 411: First image generating section, 412: Second image generating section, 431: Program

Claims (11)

A measurement system for visualizing a density gradient of a measurement object, comprising:
an input unit to which conditions for imaging the measurement object are input;
a first image generating unit that generates a background image having a pattern according to the condition input to the input unit;
a display unit that displays the background image generated by the first image generation unit;
an imaging unit that images the background image displayed by the display unit and the measurement object under the conditions;
a second image generating unit that generates a density gradient image showing the density gradient based on the captured image captured by the imaging unit;
A measurement system comprising: The measurement system according to claim 1, characterized in that the pattern has regularity. The imaging unit has an imaging element,
2. The measurement system according to claim 1, wherein the pattern is a striped pattern having light and dark areas arranged in a direction inclined with respect to a direction in which pixels of the image sensor are arranged. The measurement system according to claim 3, characterized in that the stripe pattern is a black and white binary stripe pattern. The measurement system according to claim 3, characterized in that each of the bright and dark areas has a width of 2 pixels or more and 10 pixels or less on the imaging element. The measurement system according to claim 3, characterized in that the angle at which the bright and dark areas are inclined with respect to the arrangement direction is 25 degrees or more and 65 degrees or less. The measurement system according to claim 3, characterized in that the angle at which the bright and dark areas are inclined with respect to the arrangement direction is 45 degrees. the display unit displays the background image by emitting or reflecting visible light;
8. The measurement system according to claim 1, wherein the object to be measured is a film or a plate that transmits the visible light. the display unit displays the background image by emitting or reflecting invisible light;
8. The measurement system according to claim 1, wherein the object to be measured does not transmit visible light but transmits the invisible light. A measurement system for visualizing a density gradient of a measurement object, comprising:
a display unit that displays a background image having a pattern;
an imaging unit that images the background image displayed by the display unit and a film or plate as the measurement object;
an image generating unit that generates a density gradient image showing the density gradient based on an image captured by the imaging unit;
A measurement system comprising: A measurement program executed by a computer of a measurement system for visualizing a density gradient of a measurement object,
The computer includes:
acquiring conditions for imaging the measurement object;
generating a background image having a pattern according to the acquired conditions;
displaying the generated background image;
capturing an image of the displayed background image and the measurement object under the conditions;
generating a density gradient image showing the density gradient based on the captured image;
A measurement program characterized by executing the above.

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