JPS6383873A - Form measuring device - Google Patents

Abstract

PURPOSE:To easily measure the external form of a matter to be measured by deciding the gradient of the surface element of the matter to be measured based on the element of a reflectance map having lightness most approximate to the lightness of a prescribed surface element of the matter to be measured. CONSTITUTION:The reflectance maps RM1-3 showing lightness R1-R3 corresponding to the gradient of a surface element SS of a reference matter 3A are obtained based on the sampling data DATA on the matter 3A obtained via a TV camera 5 after turning on light sources 4A-4C respectively. Then the lightness I1-I3 of a surface element SS of a matter 3B to be measured are obtained based on the sampling data DATA on the matter 3B obtained from light sources 4A-4C. Thus the gradient of elements of maps RM1-3 of the lightness R1-R3 most approximate to the lightness I1-I3 are obtained as the gradient of the surface element SS. The external form of the matter B is obtained based on the gradient of the element SS.

Description

[Detailed description of the invention] The present invention will be explained in the following order.

A: Industrial field of application B: Outline of the invention C: Conventional technology: Problems to be solved by the invention E: Means for solving the problem (Figs. 1 and 12) F: Effect (Figs. 1 and 12) Figure) Example G (Figures 1 to 14) (G1) Configuration of Example (Figure 1) (G2) Creation of reflectance map (Figures 1 to 6) (G3) Object to be measured 3B The slope of the surface element (Figs. 1 and 2)
(G4) Search for reflectance and maps (Figs. 1 and 2, Figs. 1θ to 12) (G5) Reconstruction of curved surfaces (Figs. 1 and 2) 13 and 14) (G6) Other Embodiments H Effects of the Invention A Industrial Application Field The present invention relates to a shape measuring device, and is particularly applicable to obtaining external shape information of a three-dimensional object. It is suitable.

B. Summary of the Invention The present invention provides a shape measuring device that measures the external shape of an object based on the brightness of a reference object and the object to be measured obtained by one television camera. By determining the slope of the surface element of the object to be measured based on the element of the reflectance map whose brightness is closest to the brightness of the surface element, the slope of the surface element of the object to be measured can be calculated using a simple calculation formula. Therefore, the external shape of the object to be measured can be easily measured.

C. Prior Art Conventionally, as this type of shape measuring device, a so-called contact type device has been used in which a probe is applied to the surface of an object to be measured and the surface is traced.

However, the first problem with contact-type shape measuring devices is that it takes a considerable amount of time to capture data.

Secondly, when measuring the shape of particularly large objects such as airplanes and ships, or when measuring particularly minute objects such as inspecting microfabricated objects, it is difficult to There is a problem where it cannot be applied.

Third, if the object to be measured is a soft object, the surface may be bent or depressed when the probe comes into contact with it, making it impossible to measure the correct external shape.

To solve this problem, conventional methods for measuring the external shape of an object using a non-contact method include binocular stereoscopic measurement, measurement using a distance sensor using light, and monocular measurement. It is being

D Problems to be Solved by the Invention However, conventionally, it has been difficult to realize a non-contact shape measuring device that can measure the shape of an object under sufficiently clear sunlight for practical use. .

The present invention has been made in consideration of the above points, and is based on the photometric stereo method (Pho), which is one of the monocular visual measurement methods.
This paper attempts to propose a shape measuring device that can reliably measure the external shape of an object to be measured using the tometric St'ereo method.

E Means for Solving the Problem In order to solve this problem, in the present invention, a plurality of four light sources 4B and 4C are sequentially turned on to obtain a reference object obtained through one television camera 5. Based on the sampling data DATA of 3A, the surface element S of the reference object 3A is
The brightness Rt(pr, (
11), Rt(pr, qs), Rs(pr, q
A plurality of reflectance maps RM (RM
I, RM2, RM3) and sampled data DAT of the object to be measured 3B obtained through the television camera 5 using the same light sources 4A, 4B, 4C as the reference object 3A.
Based on A, the reflectance map RM (RMl, R
The brightness II, It, and III of a predetermined surface element SS of the object to be measured 3B corresponding to M2, RM3) are determined, and the brightness II
, It, the brightness closest to 13 R1(1)r\qs
)1Rz(+)r)Qs)~R3(+)r\qyo) reflectance map RM (RMI, RM2, RM3
) is the slope (pr, qg) of the element SS of the surface element SS (
p, q), and the external shape data FOM of the object to be measured 3B is determined based on the slope (p, q) of the surface element SS.

Reflectance map RM obtained from F action reference object 3A (
RMI, RM2, RM3) element brightness Rt(pr
, Qs ), Rz(pr , Qs >, R,(pr
, Qs), the brightness II of each surface element SS of the object to be measured 3B, 1. By comparing , Outline shadow data FOM representing the shape can be obtained.

In this way, the slope of the surface element SS of the object to be measured 3B (
p, q), the brightness of the surface element ■1, II,
■ Brightness closest to 3 R+ (pr, ql), R2 (p,
, q6), the slope (pr, q,) of the element of the reflectance map of R1(pr, , q,).

), the slope of the surface element SS of the object to be measured 3B can be determined by simple calculation.

G example An embodiment of the present invention will be described in detail below with reference to the drawings.

(G1) Configuration of Example In FIG. 1, 1 indicates a shape measuring device, and table 2
above! ! The placed observation object 3 is illuminated by a plurality of light sources, for example, three light sources 4A, 4B, and 4C arranged at different positions.

The light sources 4A, 4B, and 4C are turned on one after another in order, so that they can irradiate the observation object 3 with illumination light from different directions. It is designed to produce different shades depending on the shape.

The observation object 3 is imaged by one television camera 5, and the rusk video signal VD thereof is converted into digital data in an analog/digital conversion circuit 6 and then written into a frame memory 7.

With the above configuration, the shape information generating section 8 writes the external shape information of the outer surface of the observation object 3 into the frame memory 7 as image data representing a two-dimensional brightness distribution (i.e., brightness distribution). is formed.

The shape measurement unit 1 has an image data processing device 11 consisting of, for example, a personal computer, an engineering workstation, a large computer, etc., and a bus 12 thereof.
Through this, the video data DATA written in the frame memory 7 can be taken into the image data processing device 11 as an output of the shape information generating section 8.

The image data processing device 11 has a three-dimensional data generating section 11A and a curved surface generating section 11B, and by executing the processing steps shown in FIG.
Three-dimensional data representing the inclination of the surface elements of the observation object 3 is created from the video data DATA captured in A, and a curved surface representing the surface shape of the observation object 30 is generated based on the three-dimensional data in the curved surface generation section 11B.

The three-dimensional data thus created in the three-dimensional data creation section 11A and the curved surface data created in the curved surface creation section 11B are stored via the bus 12 in an external memory 13 made of, for example, a disk storage device.

The image data processing device 11 can also read data stored in the external memory I3 via the bus 12 and display it on the graphic display 14.

Furthermore, the image data processing device 11 reads data accumulated in the external memory 13 via the bus 12 and supplies it as machining information to the NC machine tool 15.
By driving the tools of the C machine tool 15, a product having the same external shape as the observation object 3 can be cut out.

Furthermore, in the case of the embodiment shown in FIG. 1, the image data processing device 11
transfers data stored in external memory 13 to bus 12
By reading the data through the robot device 15 (7) 0, 1 and supplying it to the robot body 1G, this data can be used as the robot's eyes to control the movement of the robot body 16. being done.

(G2) Creation of reflectance map The three-dimensional data creation unit 11A of the image data processing device 11 creates a reflectance map (reflectance map) RM for the reference object 3A whose external shape is known in step SPI of FIG. At the same time, in step SP2, the object to be measured 3B is observed to obtain image data, and in step SP3, the image data of the object to be measured 3B,
The slope of the surface element is calculated based on the slope data obtained from the reflectance map.

Thereafter, the curved surface generation unit 11B of the image data processing device 11 generates a curved surface of the object to be measured based on the slope of the surface element obtained by the process of step SP3 in step SP4 of FIG.
A curved surface representing the external shape of B is reconstructed.

First, in step SPI of FIG. 2, the three-dimensional data creation section 11A creates a reflectance map RM according to the processing procedure shown in FIG. 3.

That is, a reference object 3 whose external shape is known as the observation object 3 on the table 2 in FIG.
Regarding A, a rusk video signal VD is obtained by the television camera 5 with the first light source 4A, second light source 4B, and third light source 4C turned on in sequence.

The content of the rask video signal VD obtained at this time represents a two-dimensional grayscale image PCR corresponding to the brightness of each point on the outer surface of the reference object 3A, depending on the illumination direction of the light sources 4A, 4B, and 4C. ing.

That is, when the television camera 5 is set at an upper position on the z-axis passing through the center of the hemispherical reference object 3A,
The grayscale image PCR includes surface elements SS on the reference object 3A for a circular shape similar to that seen in a plan view of the reference object 3A.
A two-dimensional grayscale image PCR is obtained by drawing an image representing the brightness of the image as a grayscale pattern on xy orthogonal coordinates. The brightness of each point (Xi, y,) on the xy coordinates of this grayscale image PCR is determined by the inclination of the surface element SS of the reference object 3A viewed from the direction of the television camera 5 (that is, the observation direction), the light source 4A, Or the brightness is determined by the direction of the illumination light from 4B or 4C.

The surface of the reference object 3A having a hemispherical external shape is xy
The height in two directions at each point (Xi, yj) on the coordinates is z-f (x 6 % yJ)...
. . . As shown in (1), it can be expressed by the equation r(xis)', ) representing the external shape of the reference object 3A.

Further, the normal vector n of the surface element SS at the point (Xi, yt) on the xy coordinates of the reference object 3A can be expressed as follows (2).

Incidentally, in equation (2), af/ax is the surface element SS (its center is at the point (Xi, yj)), as shown in Figure 4.
, and af/ay is the slope of the surface element SS in the X direction.
Indicates the inclination of the direction. The normal vector n is determined by calculating the cross product of the vector a representing the inclination in the X direction and the vector b representing the inclination in the X direction as seen from the point (x=,)'j) on the xy plane. 2) It can be expressed as follows.

As shown in FIG. 5, the reflectance map RM is expressed by a pq orthogonal coordinate system in which the slopes a f /ax and af/ay of this surface element SS are variables.

That is, if the slope p in the X direction and the slope q in the X direction are respectively expressed as p, q) can represent the inclination of the surface element SS on the reference object 3A in all directions. The slopes p and q correspond to the direction of the normal vector n at the point (Xi, 'lJ) on the xy plane. Furthermore, since this normal vector n corresponds to the brightness of the surface element SS when viewed from the television camera 5, the position of the point (p, q) on the pq orthogonal coordinates representing the reflectance map RM is represents the brightness of the surface element SS constituting the two-dimensional grayscale image PCR represented by the rask video signal VD.

Therefore, on the pq orthogonal coordinates, connect the points with equal brightness ■,
If this is expressed as an isobrightness line expressed by a function R (p, q) with slopes p and q as shown in the following equation (5), the density image PCR (Fig. ) (therefore, the slope distribution of the surface elements SS on the surface of the reference object 3A) can be represented by the isobrightness lines of the reflectance map RM.

Here, the pattern of isoluminance lines appearing on the reflectance map RM corresponds to the brightness distribution of the surface element SS, but the brightness of the surface element SS is determined not only by its slope but also by the distribution of the surface elements constituting the surface element. It is a value that also includes the influence of the nature of reflection (that is, the proportion of diffuse reflection components and specular reflection components). Therefore, in general, in order to obtain the slope of the surface element SS from the brightness of the surface element SS, it is necessary to know the reflection properties of the surface in advance and to correct this. In practice, such a configuration is extremely difficult. Have difficulty.

However, this problem can be solved by selecting a material whose surface reflection properties are the same as those of the measured object 3B as the reference object 3A, so that these elements can be included in the reflectance map RM. In practice, it is possible to obtain the correct inclination without being affected by the reflective properties of the surface, etc., without performing any correction processing on the surface. In this embodiment, an object that satisfies these conditions is selected as the reference object 3A.

In this way, the three-dimensional data creation unit 11A processes the data to obtain the reflectance map RM (RMI, RM2, RM3) formed by a large number of isobrightness lines expressed by equation (5). 1, second, third light source 4
Arithmetic processing is performed for each under the illumination conditions A, 4B, and 4C, and thus, as shown in FIGS. 6(A), (B), and (C), R+(p-q)=r...
...(6) Rz(p,,q)=1
・・・・・・(7) Rs(p, q)=1
The data of the reflectance maps RMI, RM2, and RM3 represented by (8) are stored in the external memory 13.

(G3) Inclination of surface elements of object to be measured 3B The three-dimensional data creation unit 11A performs step SP2 in FIG.
The object to be measured 3B is observed at.

At that time, the operator should move the table 2 as shown in FIG.
For example, a Darma-shaped object to be measured 3 is shown as an observation object 3 on the top.
B and the three lights [4A,
The object to be measured 3B is sequentially illuminated by the light sources 4A, 4B, and 4C without changing the illumination conditions by the light sources 4B and 4C.

The three grayscale images PCO (PCOl, p
c○2, PCO3), 3D data creation unit 11
A is three light sources 4A at all points (x,, yJ),
Luminance data representing brightness corresponding to 4B and 4C is captured and stored in the external memory 13.

Here, a grayscale image pcoi obtained by imaging the object to be measured 3B from above on two axes by the television camera 5,
PCO2 and PCO3 are shown in Figure 8 (A) and (B), respectively.
, (C), the different irradiation directions of the light sources 4A, 4B, and 4C result in images with different shadow positions. Video data DATA consisting of image data corresponding to this shadow is taken into the three-dimensional data creation section 11A.

In this way, the three-dimensional data creation section 11A creates the object to be measured 3B.
After completing the observation, in step sp3 of FIG. 2, the xy
Each point on the coordinates (x8, y,) (i=...i-1
, iS i+1..., j=...j-1
, Lj+1...) to create gray scale images PC01 and PCO at the designated points (Xi, yj).
2. Find the brightness I, , I, , ■ on PCO3, and
Isobrightness line 1 with the same brightness as ■1, 2, and ■3 (-I+, It, L
) (Fig. 6) on the reflectance map RM (RMl, RM
2, extracted from RM 3 ).

The isobrightness lines of brightness It, Iz, and Ii extracted in this way are expressed by the functions R+(p, q) and Rz(p,
q), R3(1), and Q).

Therefore, the three-dimensional data creation unit 11A solves the simultaneous equations (9) to (11), and calculates the three isoluminance lines 1+,
Reflectance map R of the intersection (p, q) of It and Iz
It is obtained by superimposing MI, RM2, and RM3.

Thus, the brightness of the point (x,,y,) on the xy coordinates when irradiated with the first, second, and third light sources 4A, 4B, and 4C is 11
, 2, ■, the slope (p, q) that simultaneously satisfies these three measurement conditions is calculated as
It can be uniquely determined using (RMI, RM2, RM3).

In this calculation process, first, the reflectance map RMl (Fig. 9(A)
)) Superimpose the isoluminance line I2 of the reflectance map RM2 obtained by irradiation with the second light source 4B, as shown in FIG. 9(B), on the isoluminance line ■1 above. Find two slope points lNC0 and INC,2 that intersect with each other. Next, Figure 9 (C
), by superimposing the isobrightness lines I of the reflectance map RM3 obtained by irradiation with the third light source 4C, one intersection point INC
, , can be uniquely determined to be the slope SS of the surface element at the position of the point (xl, yj).

In this way, the three-dimensional data creation unit 11A can uniquely find the slope of the surface element SS at the point (x,,y,) on the xy coordinates, and thereafter in the same way at all points on the xy coordinates. By performing similar calculations on the object to be measured 3B, the television camera 5 obtains a two-dimensional grayscale image PCO (PCOI, PCO2, PC
O3), the slopes of all the surface elements SS constituting the image of the observation object 3 can be determined from the two-dimensional grayscale image.

In the case of this embodiment, since the television camera 5 is used to observe from an upper position on two axes, it becomes the background for the image of the observation object 3 in the grayscale image PCO (PCOI, PCO2, PCO3). In the part a f / a x = af / a y =
It is 0.

(G4) Search for reflectance map However, in reality, in the shape information generating section 8, the 10th
As shown in the figure, sampling positions (...X1-1
\Xi % xi+1 ”””) s-(””
”) 'j-1, y4, yJ, I...) The brightness of the observation target is sampled discretely to obtain digital data, and the reflectance map is created based on this. RM (RMI, RM2, RM3
) is stored in the external memory 13 in the form of a discrete table in which elements having brightness data are repeated at intervals of a predetermined slope (pr, qs), as shown in FIG.

That is, each reflectance map RM (RMI, RM
2, RM3) is expressed in the form of a discrete equation expressed by the following equation (12).

Therefore, the grayscale image PCR (PCRl, P
A situation arises in which isobrightness lines with the same brightness as brightness I, , I, and I3 obtained by sampling CR2, PCR3) do not necessarily connect the intersection points on the elements of the reflectance map RM, and the corresponding surface elements There are cases where the slope (p, q) of SS cannot be directly determined from the intersection of the reflectance map RM.

In the case of this embodiment, the three-dimensional data creation section 11A
The slope (pr, q) from the elements of the reflectance map, the slope of the surface element SS is determined.

As shown in FIG. 12, this means that three coordinate axes 1. , rb, t. In the coordinate space consisting of 1, L, 1, . and the brightness R+(pr, qs) of each element of the reflectance map RM,
Let Rz (pr, q-) and Rs (pr, qs) be coordinate axes 1. ．． 1. , IC, the point P represented by the brightness It, Ig, I3 on the coordinate space and the brightness R, (pr% qs), Rz(pr, qs
), Rz (pr, q,), point P (pr
, Qm), and find the closest distance d to this point P.
The slope (pr, qs
) is approximated as the slope of the surface element SS.

That is, the three-dimensional data creation unit 11A
The reflectance map RM (RMI, R
M2, RM3), the slope (pr, qs
) element brightness R+ (p r, Qs), Rz(p
r, qs), Rs(pr, qs) and (
15) Calculate the brightness R+(pr, (is), Rz(pr, qs) for which the smallest value d is obtained by calculating the formula.
, R3 (pr, qs) is determined as the slope of the surface element SS of brightness It, It, It.

Subsequently, moving to the next surface element SS, the calculation of equation (15) is similarly repeated, and the slope (pr, qs) is obtained for all surface elements SS of the object to be measured 3B.

In this way, the slope of the surface element SS of the object to be measured 3B can be determined by simple calculation using the reflectance map and sampling data which are discrete from each other.

(G5) Three-dimensional data creation unit 11A through processing steps beyond reconstruction of the curved surface.
After the three-dimensional data creation process is completed, the image data processing device 11 proceeds to step SP4 in FIG. 2, and the curved surface generation unit 11B executes the reconstruction process of the curved surface representing the external shape.

This process is performed in step SP3 with the slope p of the surface element SS.
Since = a f / a x or q = ar7ay is obtained, by integrating this, the height f in two directions can be obtained.
An integral operation is performed based on the fact that (Xi, YJ) can be obtained.

As shown in FIG. 13, this calculation uses, for example, the inclination p in the
・All sampling points on j-1, jS j+1, old...) xt-t, Xi, Xi*1 ・
Old... Execute the integral.

Thus, the height f (xi, y,) of the external shape of the point CX= , y) on the xy plane is M f J (Xi) (i=...i-1, i, i+l・・・・・・j
=...j-1, L j+1・old...)...
...(16) It can be expressed as follows.

Equation (16) is expressed as L in the X direction on the grayscale image pco in FIG.
'Ay=...Yj-+ 1)'j s yj,......The slope in the X direction p = a
If f/a x is integrated from Xt-flash to XtXi, the point (Xt, yi) of the object to be measured 3B (t=...
・i-1, t,, i+1..., j=...
・It represents that the height of the external shape of j−1, L j+1) can be determined. If this integral calculation is executed for each point in the range of the image of the object to be measured 3B, as shown in FIG. 13, a line yi...
...yi1, Yj, y, ...... Upper external shape data FOM (...FOMy-J-+
, FOMy−= , FOMywj＊+ ・・・・・
・), and thus these external shape data (...FOMysj-1, FOM,
,,, FOM y + 1゜1...)
It is possible to reconstruct the curved surface representing the external shape of the object to be measured 3B.

In the case of this embodiment, the curved surface generation unit 11B executes the integration process using the linear approximation method shown in FIG. 14, based on the video data DATA sampled from the discrete positions described above with reference to FIG.

In other words, discrete coordinate positions ......(Xi-3
, y, ), (Xt-t , Yj), (Xt-+ , yj
), (Xi, yJ)... 1 found for
Around the time...1) (=-+>ha1) +! -2
1j% p (5-1) When the p-th angle 0-1 is calculated as shown in the following formula in step SP3 of Fig. 2, around this I ......T;)
u-s)i, 1) (i-21j% p +1-+)J
s p iJ...... are the width sections of the corresponding plane elements...Lt-x, Lt-z, L(-1
, L&..., it is considered that the data is obtained at the center position.

Here, the slope °”””p(1-31js p(!-1)j
When s p (i-11j sp! (16)
The integration operation based on the formula is performed in the X direction from the surface element where the image of the object to be measured 3B starts (in the case of FIG. 14, the position of the width section Li4).

Therefore, the integral calculation result f (Xi, y,) is f (Xi, yi) = 0 in the width interval 5-3,
In the following width interval Li-z, the value of f (xi, yJ) increases by -1 as the value of X increases.
It rises linearly from the value at the end (=0) along the straight line determined by the slope p<t-3).

Subsequently, when the value of
The value of the integral r (xi, yj) increases over the width interval, and as the value of It rises along the straight line of j.

Subsequently, when the value of X moves from width interval Li-1 to
The value of (Xt, y*) further increases from the value at the end of the width section L i-1 along a straight line with an inclination p=j.

In this way, based on the inclination data pij obtained for discrete sampling points (X8%)'J) from the edge of the image of the object to be measured 3B, the sampling points on the straight line yiyj extending in the X direction can be determined. ...xi-1,
Outer shape data FOM,j representing the outer shape of the object to be measured 3B at XI, XI, 1, . . . can be generated.

Then, perform this operation on all sample link points in the y direction...
...'It-+ , YJ% yj++ ...
If the calculation result is calculated, the external shape data FOM representing the three-dimensional external shape of the object to be measured 3B
(=-= F OMy-j-t - F OMy, J,
FOMy-J++...) can be generated.

According to the above configuration, the external shape of the object to be measured 3B is
can be reliably reconstructed using a non-contact method using two television cameras.

In this way, the object to be measured 3B is imaged under the same conditions as the conditions (i.e., the position of the light source, the position of the observation object, etc.) under which the surface shape of the reference object 3A as the observation object 3 was imaged. Therefore, there is no need for a process of aligning two two-dimensional images obtained from the reference object 3A and the measured object 3B.

In addition to this, the surface properties of the object to be measured 3B are determined by the reference object 3.
By matching A, it is possible to eliminate the need to correct the measurement results based on surface properties.

(G6) Other Embodiments In the above embodiment, by illuminating the observation object 3 (FIG. 1) with three light sources 4A, 4B, and 4C,
We have described the case where the reflectance maps RMI, RM2, and RM3 are created, but if the inclinations of all surface elements of the object to be measured 3B can be specified using two reflectance maps, two light sources should be prepared. Good.

H Effects of the Invention As described above, according to the present invention, when reconstructing the external shape of an object to be measured by performing integral processing based on the slope data of surface elements constituting two-dimensional image data, the reconstruction The slope data of the surface elements required for can be easily obtained from the discrete reflectance map and sampling data by simple calculation, and the external shape of the object to be measured can be reconstructed in a short time.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of a shape measuring device according to the present invention, FIG. 2 is a flowchart showing its measurement processing procedure, and FIG. 3 is a route showing a method for creating a reflectance map RM for a reference object 3A. Fig. 4 is a route diagram for explaining the slope of the surface element SS, Fig. 5 is a curve diagram showing an example of the reflectance map RM, and Fig. 6 is a reflectance map RMI formed by three light sources. ,
Route map showing RM2 and RM3, Figure 7 is measured object 3B
Figure 8 is a route diagram showing the image of the object to be measured 3B generated by three light sources, and Figure 9 is a route diagram showing the method for determining the slope of the surface element SS. 10 is a route map showing sampling points of the rask video signal VD, FIG. 11 is a chart showing a discrete reflectance map, and FIG. 12 is a route map showing a coordinate space based on brightness. FIGS. 13 and 14 are route maps for explaining a method of reconstructing a curved surface using integral processing. 1... Shape measuring device, 2... Table, 3... Observation target, 3A... Reference object, 3B... Measured object , 4A, 4B, 4C...
...Light source, 5...Television camera, 6
...Analog/digital conversion circuit, 7...
... Frame memory, 8 ... Shape information generation section, 11 ... Image data processing device, 11A ...
...Three-dimensional data creation unit, 11B...Curved surface generation unit, 13...External memory, RM (RMI to R
M3)...Reflectance map, PCO (P
COI~PC03)... Grayscale image, FOM (
...FOM y -1-1%FOM,,,,
FOMa, 5. I...)...External shape data.

Claims (1)

[Claims] Based on sampling data of a reference object obtained through one television camera by sequentially lighting a plurality of light sources, the brightness corresponding to the slope of the surface elements of the reference object is expressed. A plurality of reflectance maps are obtained, and a surface of the measured object corresponding to the reflectance map is determined based on sampling data of the measured object obtained through the television camera using the same light source as the reference object. Find the element brightness, find the slope of the element of the reflectance map whose brightness is closest to the brightness of a predetermined surface element of the object to be measured as the slope of the surface element, and based on the slope of the surface element, A shape measuring device characterized in that it obtains external shape data of the object to be measured.