JP3044285B2 - Shape measuring method and device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shape measuring method and apparatus for measuring a shape of an object suitable for a specular object.

[0002]

2. Description of the Related Art In various industrial fields, measurement of the three-dimensional shape of an object is an important technique that is indispensable for assembling and inspecting products, and also for automating processes. In addition, in products in these fields, there are many objects whose surfaces are in a mirror state or a high gloss state, such as motorcycle mufflers or cut or polished objects.

An object whose surface has a mirror surface state or a high gloss state (hereinafter, referred to as a glossy surface) (hereinafter, referred to as a glossy surface)
In the three-dimensional shape measurement of a glossy object), light is specularly reflected on the surface of the object, so that it is impossible to directly apply the three-dimensional shape measurement method for an object having a general diffuse reflection surface.

For this reason, various methods for measuring the three-dimensional shape of a glossy object have been conventionally attempted. For example, FIG. 4 shows a cubic shape measuring device proposed in Japanese Patent Publication No. 7-58172. This example same axis X on the two diffusion point source L _l placed at a distance B, a L _r, 2 units placed in their diffusion point light source and the spatial equivalent positions IT
V camera C _l, is an example of a three-dimensional shape measuring apparatus of the gloss object constituted by a C _r. In FIG. 4, an object T is illuminated simultaneously by two diffusion point light sources L _l and L _r . Here, i-th point of Pt _i on the object surface, the optical path of the light exiting the optical path of light emitted to the point Pt _i from the diffusion point light source L _l Rl _i, from the diffusion point light source L _r to the point Pt _i the When Rr _i, a4-th point on the object T from the diffusion point light source L _l Pt
light optical path Rl _a4 exiting to _a4 are regularly reflected at the point Pt _a4, it enters the optical path R'L _a4 as ITV camera C _r.

On the other hand, light of a particular optical path Rr _a4 exiting from the diffusion point light source L _r proceeds exactly the same optical path as the optical path from the diffusion point light source L _l Conversely, regularly reflected at the point Pt _a4 optical path R 'R _a4
The incident and into the ITV camera C _l. Incident angle .theta.l _a4 of light to the ITV camera, [theta] r _a4 is imaging plane I _l of each ITV camera, spot Ql on I _{r a4,} Qr _a4 position and I
It can be calculated from the focal length F of the TV camera. The positions of the reflection points Pt _a4 on the object T are incident angles θl _a4 , θr _a4
And the distance B between two ITV cameras using the principle of triangulation. The three-dimensional shape of the object T is obtained by repeatedly performing the above measurement while rotating or moving the object T. This method is excellent in that it can measure the three-dimensional shape of a glossy object with a simple configuration using only a fixed diffusion point light source and an ITV camera without the need for moving the diffusion point light source or moving mechanisms such as switching the irradiation timing. ing.

[0006]

SUMMARY OF THE INVENTION In the above method,
Regarding the measurement of the three-dimensional shape of a glossy object, only light emitted from one diffused point light source and incident on an ITV camera located at a different position from the diffused point light source is handled. However, in actual measurement, depending on the shape of the object or the position of the object, light emitted from a certain diffusion point light source may enter the ITV camera located at the same position.

For example, in the example of FIG.
Certain optical light path Rl _b4 exiting _l is regularly reflected at the point Pt _b4 with above object T, the optical path Rl _b4 the same optical path R '
incident l _b4 returns to ITV camera C _l, connecting the light spot Ql _b4. Similarly, certain optical path R emitted from the diffusion point light source L _r
light r _c4 enters the same optical path R'R _c4 regularly reflected at the point Pt _c4 on the object T returns to ITV camera C _r, point Qr _c4
Tie.

[0008] As a result, the imaging plane I _l of the ITV camera C _l
The point Ql _a4 by light from the diffusion point light source L _r, two light spots of the light spot Ql _b4 by light from the diffusion point light source L _l is the simultaneous presence. Further, the light spot by light from the diffusion point light source L _l on the imaging plane I _r of the ITV camera C _r Qr _a4
When the two light spots Qr _c4 by light from the diffusion point light source L _r is the simultaneous presence. For this reason, regarding the light spot on the image plane of the ITV camera, it is not clear which light point is due to the reflected light from the point _Pta4 , and the position cannot be calculated.

As described above, in the proposal of Japanese Patent Publication No. 7-58172, only the incident light from the diffusion point light source located at a different position from the ITV camera is dealt with, and from the diffusion point light source located at the same position as the ITV camera. Is not considered at all. Therefore, in the actual measurement, when two light spots appear on the ITV camera image plane, the light point used for calculating the measurement point position cannot be specified, or the light points between the ITV camera image planes may be erroneously corresponded. However, there is still a point to be improved in the above proposal in that there is a problem that the measurement point position cannot be calculated. Therefore, an object of the present invention is to provide a method and an apparatus for measuring the shape of a specular object with improved measurement performance.

[0010]

In order to achieve the above object, according to the first aspect of the present invention, two diffusion point light sources are installed at a fixed distance on the same axis, and each of the diffusion point light sources is provided. Two imaging devices are installed almost at the same position spatially as the light source,
Projecting light from each of the diffusion point light sources onto a measurement target, capturing the light reflected from the measurement target with each imaging device, and detecting a light spot on an imaging plane of each of the imaging devices Performing the step of storing the number of light spots, detecting the position of the light spot on the image forming surface, storing the detected position, and setting a plurality of light spots on the image forming surface. in the case of,
Compare the light spot due to the reflected light from the diffusion point light source at a position different from the position of the imaging device with the light point due to another diffusion point light source
And only the light spot having a large position is diffused to a different position.
A step of determining as the position of the light spot due to the reflected light from the point light source, and a step of detecting only the position of the determined light spot,
The angle of incidence of the reflected light on each of the imaging devices, the camera parameters of each of the imaging devices, and the diffusion point light source, the reflection of the light of the measurement object from the geometrical value relating to the installation position of each of the imaging devices Calculating the spatial position of the point.

According to a second aspect of the present invention, there are provided two diffusing point light sources installed on a gantry at a fixed distance on the same axis, and installed at substantially the same spatial position as each of the diffusing point light sources;
Two image pickup devices for picking up the light projected from the respective diffusion point light sources onto the object to be measured and reflecting the light from the object to be measured, and detecting light spots on the imaging plane of each of the image pickup devices And stores the number of the light spots, detects the positions of the light spots on the image plane, and stores the detected positions. If there are a plurality of light points on the image plane, the position of the imaging device The light point due to the light reflected from the diffusion point light source at a different position from the light point due to the light from another diffusion point light source is compared.
Only the light due to the reflected light from the diffusion point light source at different positions
Determined as the position of a point, a light point signal processing device that extracts only the position of the determined light point, and calculates the angle of incidence of the reflected light on each of the imaging devices, the camera parameters of each of the imaging devices, And a shape calculation device for calculating a position of a reflection point of light of the measurement object from a geometrical value relating to an installation position of each of the imaging devices.

According to the first and second aspects of the present invention, the position of the imaging device is determined.
And other points due to the reflected light from the diffuse point light source
Compared with the light spot of the diffusion point light source
Only the light spot is changed to the reflected light from the diffusion point light source at a different position.
The light spot due to the reflected light from the diffusion point light source located at the same position as the imaging device is removed, and only the light spot due to the reflected light from the diffusion point light source at a different position is detected.

[0013]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 shows the structure of this embodiment viewed from above. In FIG. 1, T is an object to be measured, L _l and L _r are diffusion point light sources, C _l and _Cr are ITV cameras, M _l and _Mr are half mirrors, each of which is installed on a gantry K. I have. S11L and S11R are light spot signal processing devices, and S12 is a shape calculation device.

The coordinate axes of the measuring system are shown as X-axis in the longitudinal direction of the gantry K, Y-axis and Y'-axis perpendicular to the X-axis as shown in FIG. 1, and the intersection of the X-axis and the Y-axis is taken as the origin O. , X axis and Y '
The intersection of the axes is O '. The half mirrors M _l and _Mr are located at intersections O and O ′, respectively, and their planes have, for example, angles −45 ° and + 45 ° with respect to the X axis. The diffusion point light sources L _l and L _r are respectively installed at positions at a distance D in the negative direction from O and O ′ on the Y-axis and Y′-axis, and the ITV cameras C _l and C _r The point is located on the X-axis at a distance D from each of O and O ', and the optical axis thereof is coincident with the X-axis.

That is, in both the left and right configurations, the distance from the half mirror to the diffusion point light source and the distance from the half mirror to the ITV camera are equidistant D, and the positions of the diffusion point light source and the ITV camera are equivalently the same. It has become.
Further, at this time, ITV camera C _l, between C _r, and diffused spot light source L _l, When the distance between L _r B, Y-axis, the distance between the Y 'axis is a B-2D.

In this configuration, the diffusion point light sources L _l and L _r simultaneously illuminate the entire object T. Light projected toward an object T from the diffusion point light source L _l is illuminating the object T entirely passed through the half mirror M _l. The surface of the object T is a glossy surface. Therefore, all the projected light is specularly reflected on the surface. At this time, assuming that represent the i-th point on the object T surface with Pt _i, particular optical path Rl with a1 th _a1
Is specularly reflected at the point Pt _a1 on the object T, and the light path R ′
After passing through _a1 and reflected by the half mirror _Mr , the ITV
The _light enters the camera _Cr . Regard diffused spot light source L _r, only certain light having a specific optical path Rr _a1 emitted therefrom is reflected at the point Pt _a1 on the object T plane, it passes through the optical path R'R _a1, via the half mirror M _l ITV The _light enters the camera _Cl . Here the optical path Rl _a1 and R'R _a1, and Rr _a1 and R'L _a1 is quite become the same route according to the law of specular reflection of light, the only defined path by the geometrical conditions of the measurement system.

Meanwhile, the shape of the object T, or depending on the position, the light of the particular optical path Rl _b1 in different from the optical path Rl _a1 of the light projected onto the object T from the diffusion point light source L _l, the subject is regularly reflected on the b1-th point on the object T plane Pt _b1, the optical path Rl _b1 same in the opposite direction the same position and is reflected diffuse point source L _l optical path R'L _b1 are as yet half mirror M _l of the incident on certain ITV camera C _l. Similarly, light passing through a particular optical path Rr _c1 projected on the object T from the diffusion point light source L _r is regularly reflected at a point Pt _c1 on the object T plane, the optical path in the opposite direction the same as the light path the R'R _c1 further passes through a half mirror M _r enters the ITV camera C _r. Therefore, the light spot of the plurality of the respective image plane of the ITV camera C _l, and C _r in this case (2) is to be imaged.

Light point signal processing devices S11L and S11
R detects the number of light spots on the imaging plane of each ITV camera and the positions of those light spots, and if there are a plurality of light spots, a diffusion point at a position different from the position of the ITV camera. Only the position of the light spot by the light source is extracted. Shape calculation device S12
Calculates the position of the reflection point Pt _a1 on the object T based on the principle of triangulation based on the position of the light spot on each image plane obtained from the light point signal processing devices S11L and S11R.

The measurement principle of this embodiment will be described with reference to FIG. In FIG. 2, T is an object to be measured, which is a convex object (including a plane object), and an i-th point on the surface is denoted by Pt _i.
Expressed as (x _i , y _i ). L _l and L _r are diffusion point light sources. _Cl and _Cr are ITV cameras, and their focal lengths are both F.

[0021] Here, ITV camera C _l, C _r is the point that lens principal point each O, O 'at the position of, and their optical axes are each Y, Y' is installed to match the axial In addition, it is assumed that the diffusion point light sources L _l and L _r are set at the positions of points O and O ′, respectively. This configuration is shown in FIG.
Is equivalent to the optical system of the embodiment shown in FIG.

The coordinate axes X, Y and Y 'of the measuring system are determined as shown in the figure. The Y axis and the Y 'axis are each perpendicular to the X axis,
The point of intersection of the X axis and the Y axis is the origin O, and the point of intersection of the X axis and the Y 'axis is O'
And The distance between the coordinate axes Y and Y 'is B. Respect image plane coordinate system of the ITV camera, ITV camera C coordinate axes on the image plane I _l U of _l, imaging surface of the ITV camera C _r I _r
The upper coordinate axis is W. The U axis is parallel to the X axis and perpendicular to the Y axis at -F of the Y axis, and its direction is opposite to the X axis. The intersection of the Y axis and the U axis is defined as the origin _Ou . W axis is Y '
At the position -F of the axis, it is parallel to the X axis, perpendicular to the Y 'axis, and its direction is the same as the X axis. The intersection of the Y 'axis and W-axis as the origin O _w. Also, U-axis, and W Ql the position of i-th light spot on the general axis _i (u _i), and Qr _i
And those expressed by the (w _i).

The object T is a glossy object. Accordingly, all light projected from the diffusion point light source _Ll toward the object T,
That light of the i-th optical path Rl _i is a point on the object T plane Pt _i (x _i, y _i) is regularly reflected by the optical light path R'L _i. At this time, from the law of specular reflection of light, only certain light having a specific optical path Rl _a2 is regularly reflected at a particular point _{Pt a2 (x a2, y a2} ), the optical path R'L _a2 to as ITV camera C _r The light is incident, and connects the light point Qr _a2 (wa _a2 ) on the W axis. Point Pt _i on the light even target T faces the other optical path Rl _i irradiated to the object T (i ≠ a2) but is regularly reflected by _{(x i, y i) (} i ≠ a2), their no light is incident to the ITV camera C _r.
Similarly, all projected toward an object T from the diffusion point light source L _r light, that light is also the point of the optical path Rr _i Pt _i (x
_i, becomes a light of the regular reflection by the optical path R'R _i in y _i), of those light, positive in certain only light optical path Rr _a2 certain point _{Pt a2 (x a2, y a2} ) Reflected and the optical path R'r _a2
The incident and into the ITV camera C _l, the light spot on the U axis Ql _a2
(U _a2 ).

[0024] Certain terms _{Pt a2 (x a2, y a2} ) optical path Rl _a2 and R'R _a2, and the optical path Rr _a2 and R'L _a2 relates,
The directions are opposite and have the same optical path. That is, the optical path of the light emitted from one diffusion point light source and regularly reflected by the object and incident on the ITV camera at the other position is exactly the same reverse path for each diffusion point light source. As long as is a convex object, only one can be determined.

[0025] Here, the angle between the X axis and the optical path Rl _i theta
l _i, the following equation is established when the angle between the X axis and the optical path Rr _i and [theta] r _i.

[0026]

(Equation 1)

[0027]

(Equation 2)

From the above equation, the point Pt _i (x _i ,
The position of y _i ) is generally obtained by the following equation.

[0029]

(Equation 3)

[0030]

(Equation 4)

Therefore, the position of the point Pt _a2 (x _a2 , y _a2 ) is given by the following equation.

[0032]

(Equation 5)

[0033]

(Equation 6)

As shown by the above equation, when the correspondence between the light spots on the respective image planes of the two ITV cameras is obtained, the position of the measurement point on the object is determined by the image formation of each ITV camera. It can be obtained using the positions u _i and w _i of the light spots on the surface, the distance B between the ITV cameras, and the focal length F of the ITV cameras.

On the other hand, of the light emitted from a certain diffusion point light source,
The light whose optical path satisfies a certain condition is specularly reflected at a point on the surface of the object T, returns in the opposite optical path in the opposite direction, and enters the ITV camera located at the same position as the diffusion point light source. That is, the specific optical path Rl _b2 projected from the diffusion point light source L _l
Is reflected at the point Pt _b2 (x _b2 , y _b2 ) and the light path Rlb ₂
The reverse optical path R'L _b2 enters the through ITV camera C _l the same as, connecting the light spot Ql _b2 (u _b2) on the U axis. As a result,
ITV camera C _l spot by the light from the diffusion point light source L _r is the image plane I _l of Ql _a2 (u _a2), diffuse point source L _l spot by light from Ql _b2 (u _b2) two Two light spots exist at the same time.

[0036] Similarly, light having a specific optical path Rr _c2 of the light emitted from the diffusion point light source L _r is the point _{Pt c2 (x c2, y c2} ) reflected by, identical in reverse optical path R'R _c2 the incident and into the ITV camera C _r, connecting the light spot Qr _c2 (w _c2) on the W axis.
Therefore ITV camera C _r ITV is the image plane I _r camera C _l as well as two point Qr _a2 (w _a2), and Qr _c2
(W _c2 ) exists.

Here, the relationship between the optical path of the diffusion point light source and the normal line of the object will be considered.

As shown in the figure, a point Pt _i on the object T
The normal to the tangent plane at (x _i , y _i ) is the normal N
and _{i, θxn} the angle between the X axis and the normal N _{i i} (x _i,
y _i), the angle between the optical path Rl _i and the normal N _i θrn _i
( _Xi , _yi ). At this time, the angle θrn _i (x _i , y
_i ) is represented by the following equation.

[0039]

Equation 7] _{θrn i (x i, y i} ) = θxn i (x i, y i) -θl i (x i, y i) also points the light emitted from the diffusion point light source _{L l} Pt _i (x _i , y
_i ) In order to make specular reflection at the ITV camera _Cr at
Optical path Rl _i and R'L _i must constitute a triangle having the base of the B. Therefore, the angle θrn _i (x _i , y _i )
Must always satisfy the following conditions:

[0040]

(8) θrn _i (x _i , y _i )> 0

[0041]

Xxn _i (x _i , y _i )> θ _{l i} (x _i , y _i ) On the other hand, when i = b2, the light emitted from the diffusion point light source L _{l
t b2 (x b2, y b2} ) regularly reflected by the optical path R when entering the ITV camera C _l in the same position and the spreading point light source
l _b2 and the normal N _b2 must match.

[0042]

[Formula 10] θrn _b2 (x _b2 , y _b2 ) = 0 That is,

[0043]

Equation 11] _{θxn b2 (x b2, y b2} ) = θl b2 (x b2, y b2) Here, when the object is assumed to be convex object, when x _i> x _b2, curvature K is always K ≧ 0. Therefore, the point Pt _i
The following equation holds for (x _i , y _i ).

[0044]

１２xn _i (x _i , y _i ) ≧ θxn _b2 (x _b2 , y _b2 ) (x _i > x _b2 ) On the other hand, the point Pt _i (x _i , y _i ) is observed without occlusion. the point _{Pt b2 (x b2, y b2} ) straight line passing through the (optical path) Rl _b2 respect point _{Pt i (x i, y i} ) should always be in its negative region. At this time, the following equation is established.

[0045]

(13) θl _b2 (x _b2 , y _b2 )> θ l _i (x _i , y _i ) (x _i > x _b2 ) Therefore, the following relationship is established from Expression 11, Expression 12, and Expression 13. .

[0046]

[Number 14] _{θxn i (x i, y i} ) ≧ θxn b2 (x b2, y b2)> θl i than _{(x i, y i) (} x i> x b2) the above equation, the x _i> x _b2 Time, condition θxn _i (x _i , y
_i )> θl _i (x _i , y _i ) always holds. That is, in order to satisfy the condition of Expression 9, x _i > x _b2
Must. In FIG. 2, a point Pt _a2 (x _a2 ,
position of y _a2) is _{Pt b2 (x b2, y b2} ) than always right, i.e., the position of the respect X axis x _a2 is always larger position than x _b2. Therefore, θl _b2 (x _b2 , y _b2 )> θl _a2
(X _a2 , ya ₂ ) holds. As a result, U of the image plane I _l
The position of the light point Ql _a2 (u _a2 ) on the axis is the light point Ql
_The value (u _a2 > u _b2 ) is always larger than _b2 (u _b2 ).

Similarly, regarding the ITV camera _Cr , the point P
The position of t _a2 (x _a2 , y _a2 ) is always to the left of Pt _c2 (x _c2 , y _c2 ), that is, x _a2 is always smaller than x _{c2 with} respect to the X axis. At this time, the angle θl _c2 (x _c2 ,
y _c2)> is a _{θl a2 (x a2, y a2} ). Therefore, the position of the light spot Qr _a2 (w _a2) on W-axis of the imaging plane I _r is always greater than the light spot _{Qr c2 (w c2) (w} a2> w c2).

That is, the position of the light spot on the imaging plane of the ITV camera is the position of the light spot due to the reflected light from the diffusion point light source at another position, and the position of the light point by the diffusion point light source at the same position as the ITV camera. The value is always larger than the position of the point. Therefore, by comparing the positions of the light spots on the image forming plane, it is possible to determine which of the diffusion point light sources is the light spot.

FIG. 3 shows the internal configuration of the light point signal processing devices S11L and S11R for determining a light point based on such a principle. In FIG. 3, the light spot signal processing device S11L includes a light spot detection circuit 31L, a light spot position detection circuit 32L, and a light spot determination circuit 33L. Similarly, the light spot signal processing device S11R includes a light spot detection circuit 31R, a light spot position detection circuit 3
2R and a light spot discrimination circuit 33R.

The light spot detection circuits 31L and 31R are connected to the IT
The video signals of the V cameras _Cl and _Cr are input. The light spot detection circuits 31L and 31R separate the light spot and the background signal from each input video signal by a known method such as signal level detection by a threshold circuit, detect the light spots on the image plane, and store the numbers. I do. Light spot position detection circuit 3
2L and 32R are obtained by a known method such as counting the time from the start of the scanning signal to the light spot detected by the light spot detection circuits 31L and 31R in the horizontal or vertical scanning direction of the ITV camera. The light spot position is detected and its value is stored. Light spot discriminating circuits 33L and 3
The 3R compares the light spot positions detected by the light spot position detection circuits 32L and 32R when there are two light spots, based on the data of the number of light spots detected by the light spot detection circuits 31L and 31R. Only light spots with large positions are detected. If there is only one light spot, the position of that light spot is extracted.

The shape calculation device S12 is a light spot signal processing device S
From the light spot positions obtained by 11L and S11R,
Equation 3 calculates the position of the point Pt _i on the object based on the equation (4).

[0052]

As described above, according to the first and second aspects of the present invention, the light from the diffusion point light source at a position different from the position of the imaging device is detected.
Comparing the light spot of the emitted light with the light spot of another diffuse point light source
And only the light spot having a large position is diffused to a different position.
It is determined as the position of the light spot due to the reflected light from the point light source, the light spot due to the reflected light from the diffuse point light source located at the same position as the imaging device is removed, and the light point due to the reflected light from the diffuse point light source at a different position is removed. Only detect. This makes it possible to measure the three-dimensional shape of the object without being restricted by the geometrical configuration conditions of the measurement system, such as the shape and position of the object or the installation position of the measuring device, and is widely applicable to various industrial fields. Become.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a configuration of an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a measurement principle of the present invention.

FIG. 3 is a block diagram illustrating a configuration of a light spot signal processing device according to an embodiment of the present invention.

FIG. 4 is a configuration diagram showing a conventional method for measuring the shape of a glossy object.

[Explanation of symbols]

T measurement object L _l, L _r diffusion point light source C _l, C _r ITV camera M _l, M _r half mirror I _l, I _r ITV camera image plane K pedestal S11L, S11R point signal processor S12 shape operation unit 31L, 31R Light point detection circuit 32L, 32R Light point position detection circuit 33L, 33R Light point discrimination circuit F ITV camera focal length B Distance between ITV cameras, distance between diffusion point light sources C Distance between ITV camera and half mirror, Distance between diffusion point light source and half mirror Rl, Rr Optical path of light from diffusion point light source R'l, R'r Optical path of light reflected by measurement object Pt Point on measurement object Ql, Qr ITV camera imaging Light spot on surface N normal

Claims (2)

(57) [Claims] 1. Two diffused point light sources are installed on the same axis at a fixed distance, and two image pickup devices are installed at substantially the same spatial position as each of the diffused point light sources. Projecting light from the diffusion point light source to the measurement target, imaging the light reflected from the measurement target with each imaging device, and detecting the light spot on the imaging plane of each of the imaging devices; The step of storing the number of light spots, the step of detecting the position of the light spot on the imaging plane, the step of storing the detection position, and the case where there are a plurality of light spots on the imaging plane, Compare the light spot due to the reflected light from the diffusion point light source at a position different from the position of the imaging device with the light point due to another diffusion point light source, and find that the position is large.
Only the light spot is changed to the reflected light from the diffusion point light source at a different position.
Determining the position of the light spot, detecting only the position of the determined light point, the incident angle of the reflected light on each of the imaging devices, the camera parameters of each of the imaging devices, and the diffusion Calculating a spatial position of a light reflection point of the measurement target object from a geometrical value related to a point light source and an installation position of each of the imaging devices. 2. Two diffusion point light sources installed on a gantry at a fixed distance on the same axis, and each diffusion point light source is installed at substantially the same position spatially as each of said diffusion point light sources. Two image pickup devices for picking up light reflected from the measurement object of light projected from the light source onto the measurement object; detecting light points on the image forming surfaces of the respective image pickup devices; A number of light spots on the image forming plane, respectively, and also stores the detected positions. When there are a plurality of light spots on the image forming plane, diffusion at a position different from the position of the imaging device is performed. Compare the light spot due to the reflected light from the point light source with the light spot due to other diffused point light sources , and
Of the light spot due to the reflected light from the diffusion point light source at different positions
Determine the position, and the discriminated light spot position only retrieve point signal processor, calculates the incident angle of the reflected light to the image pickup apparatus wherein each respective camera parameters of the imaging apparatus of the each, and the A shape measurement device comprising: a diffusion point light source; and a shape calculation device that calculates a position of a light reflection point of the measurement target object from a geometric value related to an installation position of each of the imaging devices.