JP4851931B2 - Human body shape measuring device and measuring method - Google Patents

Description

  The present invention relates to measurement of a human body shape using a light cutting method, and particularly relates to shortening measurement time.

  A human body shape measuring apparatus using slit light is known. In this measuring apparatus, fan-shaped slit light is extracted from a laser light source or the like and projected onto a human body, and reflected light from the human body is imaged by a camera. If the angle of the slit light with respect to the horizontal plane is known and the angle of the reflected light from the horizontal plane is known on the camera side, the three-dimensional coordinates of the human body surface relative to the camera can be determined. One slit light touches the human body in a planar shape, and the camera can obtain an image as if the human body was cut by the slit light. When the human body shape is obtained at a plurality of heights while changing the position of the slit light, a three-dimensional shape of the human body surface is obtained.

Patent Document 1 states that a marker is attached to a position serving as a reference of the human body, the shape of the human body surface is obtained with the first slit light, the marker is detected with the second slit light, and main data of the human body is obtained. is suggesting.
Patent Document 2 proposes to irradiate a target such as an electronic component with a plurality of parallel slit lights and simultaneously obtain three-dimensional data along a plurality of lines to shorten the measurement time. However, the measurement object in Patent Document 2 is a simple object such as an electronic component, a solder bump, or a conductive paste.

The inventor considered that it is necessary to shorten the measurement time in measuring the human body shape. If the measurement time is long, it becomes difficult for the person to be measured to maintain a certain posture. Therefore, it was examined to irradiate a human body with a plurality of slit lights at the same time, but it was difficult to determine which slit light was used for the reflected light. For this reason, the inventor studied a technique for determining which slit light is the reflected light from the human body, and arrived at the present invention.
JP 2004-45222 A JP 2004-37317 A

The basic problem of the present invention is that when a plurality of slit lights are irradiated at the same time, it is possible to automatically determine which slit light is the reflected light so that the human body shape can be measured at high speed. It is in.
An additional problem of the present invention is to more reliably determine the slit light.
An auxiliary problem in the present invention is to further increase the number of slit lights that can be irradiated at the same time, thereby further reducing the measurement time.

This invention is a human body shape measuring apparatus for obtaining a three-dimensional shape of a human body by irradiating a human body with slit light multiple times at different positions and imaging reflected light with a camera.
A light source for irradiating a human body with a plurality of slit lights simultaneously;
A drive unit for sequentially changing the irradiation position of the slit light;
A camera that images reflected light from the human body of the plurality of slit lights;
An image recognition unit for comparing the previous camera image with the current camera image, and assigning the reflected light in the current camera image to any of a plurality of slit lights,
An arithmetic unit for obtaining a human body shape from a combination of slit light and the reflected light is provided.
For example, a plurality of slit light sources and a camera are linearly arranged on a stage and moved simultaneously with the stage, and the plurality of slit lights are irradiated on the human body simultaneously in parallel.

The present invention is also directed to a method for obtaining a three-dimensional shape of a human body by irradiating a human body with slit light a plurality of times at different positions and imaging reflected light with a camera.
While irradiating the human body with multiple slit lights at the same time, irradiate the slit light multiple times by changing the irradiation position,
The reflected light from the human body of the plurality of slit lights is imaged with a camera,
Compare the previous camera image with the current camera image, assign the reflected light from the current camera image to one of the slit lights,
A human body shape is obtained from a combination of slit light and the reflected light.

The description relating to the human body shape measuring device in this specification also applies to the human body shape measuring method as it is, and conversely, the description relating to the human body shape measuring method also applies to the human body shape measuring device as it is.
In this specification, a camera image means image data obtained from a camera or human body shape data obtained from a camera image. If the slit light can be assigned, the camera image and the human body shape data are compatible data, and these are both referred to as a camera image for simplicity.

Preferably, the light source and the camera are both moved relative to the human body by the drive unit,
In the image recognition unit,
・ Convert the viewpoint of the previous camera image from the image captured at the previous camera position to the image captured at the current camera position, or convert the current camera image from the image captured at the current camera position to the previous camera position. Change the viewpoint to the captured image,
-From the comparison between the previous and current camera images after the viewpoint conversion, the reflected light in the current camera image is assigned to one of a plurality of slit lights.
Particularly preferably, each of the plurality of slit lights contacts the human body in a line shape,
The image recognition unit obtains the distance between the reflected light line in the previous camera image and the reflected light line in the current camera image as a comparison between the camera images after the viewpoint conversion.

Preferably, at least a pair of slit light sources and a camera are attached to each of at least four lifting platforms, and the periphery of the human body is moved up and down by the drive unit,
The human body is simultaneously irradiated with slit light from the slit light sources of the two elevators at the diagonal positions.

  In the present invention, the previous camera image and the current camera image are compared, and the reflected light from the current camera image is assigned to one of the slit lights. The reflected light in the previous camera image has been assigned to one of the slit lights, and the reflected light in the current camera image is in a predetermined range with respect to the reflected light in the previous camera image. When the image and the current camera image are compared, the reflected light of the current camera image can be assigned to any slit light. For this reason, a human body shape can be calculated | required by irradiating several slit light simultaneously, and a human body shape can be measured in a short time in connection with this.

When the camera position differs between the previous camera image and the current camera image, the images can be compared more accurately by aligning the camera positions by viewpoint conversion.
When the distance between the reflection line in the previous camera image and the reflection line in the current camera image is obtained, the two slit lights are close if the distance is small, and the two slit lights are separated if the distance is large. Therefore, the reflection line in the current camera image can be more reliably assigned to the slit light.

  When four or six elevators are arranged so as to surround the human body, and at least a pair of slit lights are irradiated simultaneously from two elevators at diagonal positions, the slit light from the elevators on the diagonal line is Since it is difficult for noise to occur, the number of slit lights simultaneously irradiated can be increased to four or more. Therefore, the measurement time can be further shortened.

  The best mode for carrying out the present invention will be described below, but the present invention is not limited to this.

  FIGS. 1-12 shows the human body shape measuring apparatus 2 of an Example and its deformation | transformation. In each figure, 3 is a table for the person to be measured to stand. For example, at four corners of the table 3, pillars 4 that also serve as lifting guides for the stage 6 are provided, and the stage 6 is moved up and down along the pillars 4. Reference numeral 7 denotes slit light from the stage 6, and the inclination angle from the horizontal plane is φ, for example, a fan-shaped planar laser beam that contacts the human body in a line. A millimeter wave radar 8 is provided on the ceiling of the measuring device 2 to measure the height of the person being measured. Instead of the millimeter wave radar 8, a human body shape may be photographed with a plurality of cameras to obtain a rough three-dimensional shape of the human body. The millimeter wave radar 8 may not be provided. A computer 10 controls the stage 6 and the millimeter wave radar 8.

  The structure of the stage 6 is shown in the upper right of FIG. . The camera 14 is arranged so as to be aligned with the lasers 11 and 12, and the reflected light of the slit light is imaged by the camera 14 with the center of the visual field facing the horizontal direction through the infrared transmission filter. As a result, the reflected light from the human body enters the vicinity of the center of the field of view of the camera 14, and image distortion can be reduced. Then, the stage 6 is moved up and down along the support column 4 by an elevating motor. In the embodiment, the support column 4 is moved from top to bottom, and the human body structure is measured by irradiating the measurement subject with slit light a plurality of times, for example, each time. To do. The wavelengths of the infrared lasers 11 and 12 may be the same or different. A single infrared laser beam may be divided into two by a half mirror or the like to obtain two parallel slit lights.

  In FIG. 2, the configuration of the computer 10 is shown. The controller 20 controls the entire human body shape measuring device 2, and moves up and down the four stages 6 by the lifting motors M <b> 1 to M <b> 4 via the lifting control 21. In the embodiment, the stage 6 moves from the top to the bottom at a constant speed. During this period, the lasers 11 and 12 are simultaneously emitted at a predetermined timing, and the reflected light is received by the camera 14 to obtain the human body shape. The imaging control 22 controls the lasers 11 and 12 of the four stages 6 and the camera 14, and the millimeter wave radar 8 outputs the height of the person to be measured.

  The camera images from the four stages 6 are input to the image memory 24 in which the area is divided for each stage, and the reflected light image from the person to be measured in the image memory 24 is assigned to either the upper or lower side by the H / L allocation 26. Assign to slit light. When the reflected light is assigned to the slit light, three-dimensional data of the human body shape can be calculated by the coordinate calculation 28 and stored in the human body data storage unit 30. In addition to this, a database 32 storing the human body shape may be provided. For example, only the coordinates of the feature points of the human body may be obtained and input to the database 32 to read the human body shape data. In the allocation of slit light, human body data measured up to the previous time may be input to the database 32, and human body data corresponding to the current camera image may be read from the database 32 and predicted, and allocation may be performed based on this. .

  In the allocation of slit light, it is necessary to determine which reflected light corresponds to which slit light at the beginning of measurement. When the height of the person to be measured is known by the millimeter wave radar 8 and the person to be measured stands at the center of the table 3, which slit light is reflected at the top of the head is determined, and the slit light and the reflected light can be associated with each other. . Alternatively, when the human body shape of the person to be measured is imaged with a stereoscopic camera before measurement and rough human body shape data is obtained, an initial value of which slit light corresponds to which reflected light can be obtained. Once the assignment of the correspondence between the slit light and the reflected light is successful, the following reflected light can be associated with the slit light based on the previous reflected light.

  FIG. 3 shows the measurement algorithm in the embodiment for one frame, that is, for one camera image. In FIG. 3, it is assumed that the association between the slit light and the reflected light has already been completed. Further, H indicates the upper slit light, that is, the slit light from the infrared laser 11, and L indicates the lower slit light, that is, the slit light from the infrared laser 12. The upper and lower infrared lasers 11 and 12 on one stage 6 emit light simultaneously. C represents the current camera position, and C0 represents the camera position one frame before. D indicates the height from the camera to the light source (infrared lasers 11 and 12), DH indicates the distance between the upper infrared laser 11 and the camera 14, and DL indicates the distance between the lower infrared laser 12 and the camera 14. Φ represents the angle of the slit light from the horizontal plane, and θ represents the angle of the incident light to the camera from the horizontal plane. P indicates a reflection point on the virtual projection surface, and subscript 0 indicates the previous reflection point, which is the reflection point by the slit light with subscript H or subscript L. S is a reflection line on the human body surface. In the figure, the direction from the camera 14 toward the measurement subject in the horizontal direction is the z direction, the vertical direction is the y direction, and the remaining direction is the x direction. Since the lasers 11 and 12 irradiate slit light that contacts the human body in a line shape, the angle θ varies depending on the x direction. Therefore, a change in the human body shape in the x direction is represented by a change in θ, and the reflected light is not a point but a line on the human body surface.

  The current camera image includes noise reflected by the support column 4 and the like, and the position of the reflected light is remarkably different from the reflected light from the human body surface, so that it is removed and the remaining reflected light is thinned. The order of noise removal and thinning is arbitrary. Since the camera 14 captures an infrared image, the visible light in the room does not become noise, and a black curtain or the like is not necessary for the table 3. At the same time, the image data on one frame, that is, the image data on the previous frame is read, and the human body data corresponding to the lower slit light is converted to the current camera position.

  The current camera image is compared with the data obtained by converting the previous camera image into the current camera position, and the reflected light in the current camera image is assigned to the upper slit light H or the lower slit light L. For example, if there are two reflected light lines above and below in the current camera image, the one that is close in distance and close in shape to the previous reflected light line corresponds to the slit light H, and the distance is far away. The one that is apart corresponds to the lower slit light L. If there are no two reflected light lines parallel in the vertical direction in the current camera image, the distance from the previous reflected light line is within a predetermined range and the shape is similar to the slit light H, the distance is Those outside the predetermined range or dissimilar in shape correspond to the lower slit light L.

  When the reflected light in the current camera image is associated with the upper slit light H and the lower slit light L, three-dimensional coordinates corresponding to the reflected light can be obtained. For example, in the coordinate system having the camera position as the origin, the coordinates (z, y) of the human body surface can be obtained as z = D / (tan θ + tan φ) and y = Dtan θ / (tan θ + tan φ). Here, θ is a variable that varies along the line of reflected light. When the coordinates of the camera position are added to the coordinates of (z, y) as an offset, three-dimensional data of the measurement line on the human body surface is obtained. If the above process is repeated every time one frame is captured, a human body shape is obtained.

  FIG. 4 shows an operation pattern of the four stages 6. In 1), four stages 6 are caused to emit light one by one in a time-sharing manner. For example, about 10 to 50 msec is required for imaging, and about 5 to 10 msec is required for transfer from the camera to the image memory. For example, when 25 msec is required for imaging one frame, one imaging cycle is 100 msec. If the human body shape is measured within 10 seconds, for example, the number of measurements is 100 cycles, and the interval between the upper and lower frames is about 20 mm.

  2) in FIG. 4 is an example in which the two stages on the diagonal line emit light simultaneously. For example, if 25 msec is required for one imaging, the measurement cycle is 50 msec. If slit light from the other side of the diagonal line becomes noise, change the wavelength of the infrared laser on both sides of the diagonal line, and install a band-pass filter on each camera so that it is not affected by the slit light on the opposite side of the diagonal line. .

  FIG. 5 schematically shows the relationship between the upper and lower slit lights H / L and the two camera images. C indicates the current camera position, C0 indicates the previous camera position, and the angle φ formed by each slit light with the horizontal plane is constant. The data directly obtained from the camera image is the reflection points PH0 to PL on the virtual projection plane, the distance between the camera position and the light source position of the upper slit light H is DH, and the light source of the lower slit light L is The interval is DL.

  FIG. 6 shows the conversion from the angle θ to the coordinates (z, y) in the camera image. Here, it is assumed that the slit light from the upper and lower sides is known, and the height from the camera position to the light source of the slit light is D. As is apparent from FIG. 6, the relationship y = ztan θ and D−y = ztanφ. (Z, y) can be obtained from this. In addition, the coordinate system used in the embodiment is shown on the lower left side of FIG.

  7 to 9 show the disappearance of reflected light and the generation of a new reflection line. For example, as shown in FIG. 7, when slit light is irradiated near the shoulder of a human body, one reflected light may not reach the camera position C. In this case, one line of reflected light is obtained for the upper and lower slit lights H / L.

  The reflected light may be blocked by the human arm or other obstacles and may not reach the camera position. Such an example is shown in FIG. Here, the reflected light from the chest with respect to the lower slit light L is blocked by the arm and does not arrive at the camera.

  FIG. 9 shows the generation of a new reflected light line. For example, when only reflected light for the chest or back was obtained last time, new reflected light from the arm may be detected. In such a case, a new reflected light line is generated on the image, and it can also be said that the reflected light line corresponding to the lower slit light L is split into two.

  FIG. 10 schematically shows viewpoint conversion in the embodiment. The position of the reflection point with respect to the previous slit lights H0 and L0 is known. Therefore, when this position is viewed from the current camera position C and a virtual camera image is created, the positions of the reflection points are PH0 ′ and PL0 ′ on the left side of FIG. The current camera image includes reflection points PH and PL, and it is necessary to determine which slit light corresponds to them. Therefore, the reflection point PH for the upper slit light this time is close to the reflection point PL0 ′ for the previous lower slit light, and the reflection point PH for the lower slit light is the far one.

  FIG. 11 shows the relationship between the reflection line SL0 obtained by changing the viewpoint of the reflection line in the previous camera image and the current reflection lines SH and SL. If the slit light is close, the distance between the reflection lines is small and the shape is similar. On the other hand, if the interval between the slit lights is large, the distance between the reflection lines is large and the shapes are difficult to match. Therefore, it is determined by which slit light the current reflection line is based on the two evaluation criteria of the distance between the reflection lines and the similarity of the shape. If the definition or calculation method of the distance is devised, the similarity of the shapes of the two reflection lines and the distance between the lines can be combined into one concept.

  FIG. 12 shows allocation of reflected light to slit light in the modification. Whether the position of the reflection point P0 by the previous lower slit light L0 is known, and whether the current reflection point P is due to the upper slit light H (solid body shape in FIG. 12) or the lower slit light L ( The human body shape of the chain line in FIG. From the incident angle θ to the camera, it is possible to obtain the coordinates PH when the upper slit light H is used, and the coordinates PL when the lower slit light L is used, and Cz and Cy are offsets. . Since θ is a variable, the line on which the reflection points P0 are arranged is SL0, the reflection line on the human surface when the upper slit light H is used is SH, and the human body surface when the lower slit light L is used is the reflection line on the human body surface. If the reflection line is SL, three lines are obtained in the three-dimensional space. If the distance between the previous line SL0 and the line SH is small and the shapes are similar, SH is a correct human body surface line. When the distance between SL0 and SH is large and the shapes are dissimilar, the reflection line from the upper slit light disappears, and the reflection line is assigned to the slit light L.

  In the embodiment, the stage 6 is moved from the top to the bottom with respect to the table 3, but it may be moved from the bottom to the top. Further, the stage 6 may be rotated around the base 3 on the circumference. In the embodiment, two infrared lasers 11 and 12 are provided on one stage 6, but three or more infrared lasers may be provided. In this case, the current reflected light is assigned based on a comparison with the lowermost slit light in the previous camera image. Instead of tilting the slit light from the horizontal plane, the human body may be irradiated in the vertical direction by tilting from the vertical plane. In the embodiment, the infrared lasers 11 and 12 and the camera 14 are driven in a time-sharing manner for each stage 6, but these are driven all at once, and the reflected light from the slit light of other stages is removed in the same manner as in the embodiment. May be. That is, every time one frame is imaged, the reflected light from the slit light from its own stage is obtained, and the reflected light from the slit light from the other stage is removed. In the next frame, it is determined from the comparison with the reflected light with respect to the slit light of the previous stage of the self, which is reflected light by the slit light of the own stage.

In the embodiment, the viewpoint of the previous camera image is converted. However, for the current camera image, provisional three-dimensional coordinates for the upper and lower slit lights may be obtained and converted to the viewpoint of the previous camera image. In this way, since it is necessary to obtain the three-dimensional coordinates corresponding to the current camera image a plurality of times before the viewpoint conversion, the amount of calculation increases. In the embodiment, except for the allocation to the slit light at the start of measurement, only the previous camera image is used, but the human body shape predicted from the database 32 may be used as an auxiliary.

Plan view of the human body shape measuring apparatus of the embodiment Block diagram of the human body shape measuring apparatus of the embodiment The flowchart which shows the data processing algorithm in the human body shape measurement of an Example FIG. 4 is a timing chart showing imaging and data transfer of four cameras in the embodiment, where 1) shows a basic pattern and 2) shows a high-speed pattern. The figure which shows typically two upper and lower slit lights H / L, the last camera image, and this camera image in an Example. The figure which shows the calculation method of the human body shape from a camera image Diagram showing disappearance of reflected light Diagram showing disappearance of reflected light Diagram showing generation of new reflected light The figure which shows the viewpoint conversion with respect to the human body shape data of one frame upper part in an Example. The figure which shows discrimination | determination of slit light by the comparison with the image after viewpoint conversion in an Example The figure which shows the modification of discrimination | determination of slit light

Explanation of symbols

2 Human body shape measuring device 3 units 4 support 6 stage 7 slit light 8 millimeter wave radar 10 computer 11, 12 infrared laser 14 camera 20 controller 21 lifting control 22 imaging control 24 image memory 26 H / L allocation 28 coordinate calculation 30 human body data storage Part 32 database

M1 to M4 Lifting motor H Upper slit light L Lower slit light C Camera position C0 Camera position on one frame D Height from camera to light source
P Reflection point on virtual projection plane φ Angle of slit light from horizontal plane θ Angle of incident light on camera from horizontal plane S Reflection part of human body surface

Claims (5)

In a device that irradiates a human body with slit light multiple times at different positions and captures reflected light with a camera to obtain a three-dimensional shape of the human body.
A light source for irradiating a human body with a plurality of slit lights simultaneously;
A drive unit for sequentially changing the irradiation position of the slit light;
A camera that images reflected light from the human body of the plurality of slit lights;
An image recognition unit for comparing the previous camera image with the current camera image, and assigning the reflected light in the current camera image to any of a plurality of slit lights,
An apparatus for measuring a human body shape, comprising an arithmetic unit for obtaining a human body shape from a combination of slit light and reflected light. The light source and the camera are both moved with respect to the human body by the driving unit, and
In the image recognition unit,
・ Convert the viewpoint of the previous camera image from the image captured at the previous camera position to the image captured at the current camera position, or convert the current camera image from the image captured at the current camera position to the previous camera position. Change the viewpoint to the captured image,
The human body shape measurement according to claim 1, wherein the reflected light in the current camera image is assigned to one of a plurality of slit lights based on a comparison between the previous and current camera images after the viewpoint conversion. apparatus. The plurality of slit lights are in line contact with the human body,
The image recognition unit obtains a distance between a reflected light line in the previous camera image and a reflected light line in the current camera image as a comparison between the camera images after the viewpoint conversion. The human body shape measuring apparatus according to claim 2. At least a pair of slit light sources and a camera are attached to each of at least four lifting platforms, and the periphery of the human body is raised and lowered by the drive unit,
The human body shape measuring apparatus according to claim 1, wherein the human body is irradiated with slit light simultaneously from the slit light sources of the two elevators at diagonal positions. In a method for obtaining a three-dimensional shape of a human body by irradiating a human body with slit light multiple times at different positions and capturing reflected light with a camera.
While irradiating the human body with multiple slit lights at the same time, irradiate the slit light multiple times by changing the irradiation position,
The reflected light from the human body of the plurality of slit lights is imaged with a camera,
Compare the previous camera image with the current camera image, assign the reflected light from the current camera image to one of the slit lights,
A human body shape measuring method, wherein a human body shape is obtained from a combination of slit light and the reflected light.

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