KR100540192B1 - Apparatus and method for measuring three-dimensional shape - Google Patents

Abstract

A three-dimensional shape measuring apparatus and a measuring method are disclosed.

The disclosed measuring device is configured to project a three-dimensional shape from a moire pattern formed by a first lattice pattern obtained through an image sensing device and a second lattice pattern generated by a computer after projecting a lattice pattern generated by using a liquid crystal display device onto a subject. The measurement method disclosed can effectively remove high frequency noise from moire fringes by moving the first and second lattices in the same period and averaging the moire fringes before and after moving the lattices. To help.

As a result, a three-dimensional shape can be easily measured using a simple device, and high frequency noise can be effectively removed to obtain a clearer three-dimensional shape.

Description

Apparatus and method for measuring three-dimensional shape}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus and a method for measuring the shape of a subject three-dimensionally and precisely by an interference fringe using a liquid crystal display element and a computer generated grid pattern.

A three-dimensional shape measurement device using moiré interference fringes forms a moiré interference fringe by superimposing a lattice pattern that appears by irradiating light with a certain shape on the surface of an object to be inspected (hereinafter referred to as an object) and a lattice pattern as a reference. And a device that obtains information about the height of the object surface by measuring and analyzing the interference fringes. Such a measuring method is widely used in the medical and industrial fields because it is possible to easily and quickly obtain a three-dimensional shape of a subject. Here, in particular, a moiré interference pattern, which is a spatial interference pattern, is used. The moiré pattern is a pattern that appears when overlapping spatial patterns having periodicity are illustrated in FIG. 1.

There are two methods of measuring the three-dimensional shape of the subject by using the moiré interference fringe. The shadow method is a method of measuring the surface shape of a subject by using a moire fringe generated from the shadow of the lattice pattern appearing on the surface of the subject without using a lens, and the projection method is a projection of the grid projected onto the subject using a lens. It is a method of measuring the surface shape of a subject by using a moire fringe generated from an image.

Figure 2 shows a shadow phase transition moiré three-dimensional shape measurement apparatus using a conventional grid. In this measuring device, the light emitted from the light source 100 passes through the grating 103 to form a grating shadow on the surface of the object p or a grating image by the talbot effect. The grating 103 used here functions to change the intensity of transmitted light. The moire pattern is formed by combining the shadow image of the grating 103 and the pattern of the grating itself, and the moiré pattern thus generated is called a shadow moiré (Vol. 32, No. 7 Optical Engineering, 1668-1674, 1993). This moiré pattern is measured using a two-dimensional array of image sensing elements, and in order to calculate the phase of the moiré pattern, a plurality of phase-shifted moire patterns are required ("Phase Shifting Intererometery, in Optical Shop Testing, D. Malacare , 2nd Ed.John Wiley & Sons Inc, New York, 1992)

In order to obtain a phase shifted moire fringe, the grating 103 is moved by the driving means D toward the subject p or away from the subject p. Then, since the phase of the interference fringe changes in accordance with the movement of the grating 103, three or more phase shifted moire fringes can be obtained. As described above, the phase shifted moiré pattern generated by moving the grating 103 is formed on the image sensing device 110 by the imaging lens 109. The image sensing device 110 sequentially repeats the measurement of the phase shifted moiré pattern and the movement of the grating 103. Using the plurality of phase shifted moire fringes obtained here, three-dimensional shape information of the object can be obtained through a known analysis method.

Another three-dimensional shape measuring device is a projection moiré measuring device using the first and second gratings 112 and 115, as shown in FIG. The projection moiré measuring apparatus forms an image formed while the light irradiated from the light source 111 passes through the first lattice 112 on the subject p by the first imaging lens 113, and the subject p ) Is imaged on the second grating 115 by the second imaging lens 114. In addition, the image formed on the second grating 115 and the image of the second grating 115 itself are formed on the image sensing device 117 by the third imaging lens 116 to obtain a moire pattern. .37, Optical Engineering, 1005-1010, 1998)

In the above-described projection moiré measuring device, the phase shift of the moire fringe can be obtained by using the change of the relative displacement of the first and second gratings 112 and 115. In the shadow moiré measuring device, the grating is moved forward and backward with respect to the subject p to perform phase shift. In the projection moiré measuring device, the first and second gratings 112 and 115 are driven. The moiré pattern shifted in the vertical direction by D) is obtained. The three-dimensional shape information of the subject can be obtained by analyzing the phase shifted signal obtained here through a known analysis method.

By the way, the shadow measuring device has the advantage that the installation is simple, but because the shadow of the grid should be used only when the grid and the subject can be sufficiently approached, there is a disadvantage. In order to solve such a problem, a projection measuring device is preferred.

In the case of the projection measuring device, an expensive precision optical system is required to form a moire fringe by forming a grid pattern formed on an object to the second grid 115 and to form the moire fringe on the image sensing element 117 again. Therefore, a simplified system has been proposed that does not require the second imaging lens 114 and the second lattice 114 required in the projection equation.

In addition, shadow or projection devices are limited in the size and measurement resolution of the measurable object depending on the number of pixels of the two-dimensional image sensing device used. As a result, the size and length of the measurable object are limited, and thus the measurement object is inevitably limited. In addition, during the measurement, there is a restriction that the subject must be in a stationary state. Therefore, it is not only suitable for measuring the three-dimensional shape of the moving object, but also the field of application is very limited because it is impossible to measure the shape of the object with curvature.

In addition, there is no choice but to mechanically move the grid for the phase shift of moire fringes. Due to such mechanical driving, the phase shift speed is slow, the speed control is difficult, and the grid is difficult to manufacture and the manufacturing cost is high.

On the other hand, in order to further simplify the projection measuring apparatus, a structured pattern projection apparatus has been proposed for measuring a shape by projecting a structured pattern onto a subject. Referring to FIG. 4, an image formed while the light emitted from the light source 120 passes through the grating 121 is imaged on the subject p by the first imaging lens 122, and the grating 121 projects. The image of the inspected object p is again imaged on the image sensing device 127 by the second imaging lens 124 to obtain an image of the inspected object p on which the grating is projected. Here, the displaced projection grid image is obtained by horizontally moving the grid pattern for three-dimensional shape extraction. (Vol. 32, Optical Engineering, 610-615, 1997)

 In such a measuring device, the imaging lens 122 forms an image of the grating 121 on the subject p, and then measures the image formed on the subject with the image sensing element 127, and then the image and the computer. The moire pattern is generated from the generated reference grid to measure the three-dimensional shape.

Here, a method of using a logical operation of a reference grid and an image formed grid (logical moiré method) and a computer generated grid and an image formed grid are superimposed, and only a moire pattern is separated using a low pass filter. There is a method of low frequency passing.

Since the logic moiré method uses moire patterns generated by logical operations between gratings, spatial frequencies corresponding to the gratings act as high frequency noises, and thus a sharp pattern cannot be obtained.

In the low pass method, a low pass filter is used to remove high frequency noise. However, when the shape of an object is complicated, the noise cannot be effectively removed.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object thereof is to provide a three-dimensional shape measuring apparatus having simple equipment, low manufacturing cost, and high measuring speed.

It is also an object of the present invention to provide a method for measuring a clear three-dimensional shape by simply and effectively removing high frequency noise.

In order to achieve the above object, the three-dimensional shape measuring apparatus according to the present invention is disposed between the light source and the object under test to generate a first lattice pattern, and moves the first lattice pattern by electrical control. A first lattice pattern generating unit having a liquid crystal display element, and an image sensing element configured to capture a first lattice image formed on an object through which light emitted from the light source passes through the liquid crystal display element; The second grid pattern is generated, the second grid pattern is moved at the same period as the first grid pattern, and the interference of the high-frequency noise is removed by the first grid pattern and the second grid pattern input from the image sensing element. Computer for generating a pattern; characterized in that it comprises a.

The first grid pattern generating unit may be provided in plural and may be disposed around the object at predetermined intervals.

In order to achieve the above object, a three-dimensional shape measuring method according to the present invention comprises the steps of generating a first grid pattern by the liquid crystal display element; Imaging the first lattice pattern on a subject by allowing light emitted from a light source to pass through the liquid crystal display element; Generating a second plaid using a computer; Photographing the first lattice pattern and inputting the same to the computer, and multiplying the first lattice pattern by the second lattice pattern to form an interference fringe; The first lattice pattern is moved by pixel-by-pixel electrical control of the liquid crystal display, and the second lattice pattern is moved at the same period as the first lattice pattern, thereby generating a moire pattern from which noise is removed through a lattice calculation process. It characterized in that it comprises a step.

In order to achieve the above object, the three-dimensional shape measuring method according to the present invention comprises the steps of: imaging the first grating pattern generated by light passing through the first grating pattern on the subject; Generating a second grid pattern; Forming a first interference fringe by the first lattice and the second lattice; Moving the first grid pattern and the second grid pattern at the same period; Forming a second interference fringe by the moved first lattice and the second lattice; And removing the noise by taking the average of the first and second interference fringes.

Hereinafter, an apparatus and method for measuring a three dimensional shape according to an exemplary embodiment of the present invention will be described in detail with reference to the accompanying drawings.

In the three-dimensional shape measuring apparatus according to the present invention, a lattice image is generated by using a liquid crystal display device and a computer, and the lattice images are shifted at the same period to realize the phase shift of the moire pattern.

According to an exemplary embodiment of the present invention, a three-dimensional shape measuring apparatus includes a first grid pattern generating unit having a light source 10 and a liquid crystal display element 15, and a computer generating a second grid pattern according to FIG. 5A. 25).

The light emitted from the light source 10 is moiréed by the interference between the first lattice pattern formed on the subject p through the liquid crystal display element 15 and the second lattice pattern generated by the computer 25. A pattern is formed.

In addition, the image sensing device 20 photographing the first lattice pattern formed through the liquid crystal display device 15 is provided. A first imaging lens 17 is provided between the liquid crystal display element 15 and the object p, and a second imaging lens 18 is provided between the object p and the image sensing device 20.

Light emitted from the light source 10 passes through the liquid crystal display element 15 and the first imaging lens 17 to generate a first lattice pattern on the object p. A first plaid is formed on the object p, and the first plaid is photographed by the image sensing device 20 through the second imaging lens 18.

The light source 10, the liquid crystal display element 15, and the first imaging lens 17 are configured as a set to form the first unit 30, and the second imaging lens 18 and the image sensing device 20 are provided. ) May be configured as a set to form the second unit 30. The first grid pattern is generated by the first unit 30 and the second unit 35.

A first plaid is input from the image sensing device 20 to the computer 25, and the first plaid and the virtual second plaid formed by the computer 25 interfere with each other to form a moire pattern. .

5B is a view for explaining the principle that the first lattice pattern is generated by the liquid crystal display device 15 and the first lattice pattern is phase shifted.

The liquid crystal display device 15 is formed by arranging a plurality of pixels 15a two-dimensionally (n × n), and adjusting the amount of light transmitted by changing the π intensity of the driving voltage for each pixel. For example, by turning off the pixels in the odd-numbered column and turning on the pixels in the even-numbered column among the pixels of the (n × n) array, the first grid pattern may be formed. Alternatively, the first lattice pattern can be phase shifted by [pi] by turning off the pixels in the even column among the pixels of the (n × n) array and turning on the pixels in the odd column. This has the same effect as phase shifting the moire pattern by mechanically moving the existing lattice. Therefore, in the device according to the present invention, the phase shift effect can be accurately and quickly obtained through on-off and brightness control by simple electrical operation of the liquid crystal display.

The first grid pattern may be moved by on-off control or brightness control of each pixel of the liquid crystal display device 15. Instead of causing a phase shift of moire fringes by mechanically moving the existing lattice, the liquid crystal display device 15 may cause phase shift by electrically changing a region through which light passes for each pixel. That is, in the liquid crystal display device 15, the phase shift can be implemented simply, precisely and quickly by the electric action for each pixel.

Meanwhile, in the present invention, the second lattice is moved by the same distance as the first lattice is moved through the liquid crystal display device 15. The second plaid can simply be moved through the computer 25.

The moved first lattice pattern passes through the first imaging lens 15 to form an image on the subject p, and then passes through the second imaging lens 18 to form an image on the image sensing device 20. The first lattice photographed by the image sensing device 20 is input to the computer 25, and the first lattice pattern interferes with the second lattice pattern moved by the computer 25 at the same distance as the first lattice pattern. The moiré pattern shifted out of phase is formed.

6 (a) and 6 (b) show the results obtained by moving the first lattice pattern formed by the liquid crystal display device 15 by a predetermined distance by electric action, respectively. FIGS. 6 (c) and 6 (d) shows images obtained by virtually moving the second lattice pattern formed by the computer 25 by a predetermined distance.

When the grid is moved in this way, the phase shift of the moire pattern appears. At this time, the purpose of moving the first and the second grid pattern at the same period is not only to shift the phase of the moire pattern, but also to remove noise patterns that interfere with the three-dimensional shape measurement. In order to shift the phase of the moiré pattern, the second plaid generated by the computer must also be moved by the same period with respect to the first plaid. Here, the phase shift occurs even when only one of the first grating and the second grating is moved, but the noise mixed in the moire fringe can be effectively removed by moving the first grating and the second grating at the same period.

When the first and second grid patterns are multiplied by the intensity functions, four images as shown in FIGS. 7A to 7D are generated. 7 (a) is an image obtained by multiplying the lattice patterns of FIGS. 6 (a) and 6 (c), and FIG. 7 (b) is an image obtained by multiplying the lattice patterns of FIGS. 6 (a) and 6 (d). to be. 7 (c) is an image obtained by multiplying the lattice patterns of FIGS. 6 (b) and 6 (c), and FIG. 7 (d) is multiplied by the lattice patterns of FIGS. 6 (b) and 6 (d). This is a video obtained.

7 (a) to 7 (d), not only the moiré pattern but also all the patterns corresponding to the lattice used to generate the moiré pattern exist. Here, in order to find out the surface shape of the subject p, only the moire fringe is extracted separately from these patterns to calculate the surface shape of the subject.

In the present invention, the moire fringe is extracted by using the fact that the moire fringe is generated by the relative difference between the first lattice fringe (measured grid fringe) and the second lattice fringe (virtual lattice). That is, even if the first grating and the second grating having a certain difference are moved by the same distance, the moire fringe does not change, but the patterns corresponding to each of the first grating and the second grating change with the movement of the grating. The moiré pattern is extracted by adding images that are made to have the same moiré pattern to each other.

The moiré pattern is generated by the order of each line present in the grid, i.e. the difference in the number corresponding to the order of each line. Therefore, when the two gratings are moved together so that the distance between each line of the first grating and the second grating does not change, there is no change in the moire pattern generated. However, high frequency noise such as a pattern corresponding to each of the first grating and the second grating moves together as the grating moves. Therefore, by taking the average of the patterns obtained by moving the first grating and the second grating at the same distance (or the same period), the high frequency noises such as the pattern corresponding to the grating used become constant and disappear. For example, if you integrate the cosin function by one period, it becomes 0. If you average the moving grid with periodicity, it becomes a constant value.

When the first grid and the second grid are moved together, the moire fringes have the same shape, while the high frequency noises become constant values and disappear so that the moire fringes become more clear.

Therefore, if the grid is moved without changing the relative order between the first grid and the second grid, taking the average of the intensities of the images of each of the moved grids, the intensity distribution of the moire pattern remains unchanged, while the other high frequency The moiré patterns become more vivid because the patterns cancel each other out.

7 (a) and 7 (d), it can be seen that the moire fringes shown in the two images are the same, while the images corresponding to the grids are moved by half of the grid spacing. This means the movement of the grating, which in turn shifts the phase of the moiré pattern. This movement of the grid is necessary not only for the phase shift of the moire pattern but also for image processing that extracts only the moire pattern.

7 (b) and 7 (c) also show the same moiré monie, while the images corresponding to the lattice are shifted by half the lattice spacing.

If the images with the same moiré pattern are added, the moiré pattern becomes clearer. 8 (a) is an image obtained by adding the images of FIGS. 7 (a) and 7 (d), and FIG. 8 (b) is an image obtained by adding the images of FIGS. 7 (b) and 7 (c). In this way, high frequency noise can be removed and a clearer phase shifted moire pattern can be obtained.

9 (a) to 9 (c) show moiré interference fringes obtained through three phase shifts, and phase shifts are performed by 2π / 3. For example, each pixel constituting the liquid crystal display device 15 has a phase difference of 2π / 3.

10 (a) to 10 (d) show moiré interference fringes obtained through four phase shifts, and are phase shifted by π / 2. When four phase shifts are made using the said liquid crystal display element 15, each pixel which comprises the liquid crystal display element 15 has a phase difference of (pi) / 2. As such, when the first grid pattern and the second grid pattern are moved at the same period (or distance), high frequency noise can be removed.

Next, a flowchart showing a method of measuring a three-dimensional shape through the moire interference fringe according to the present invention is shown in FIG.

First, the three-dimensional shape measuring method according to the present invention generates a first plaid (s10), and generates a second plaid (s12). A first moire interference fringe is generated through a lattice operation of the first plaid and the second plaid (S13).

Then, the first plaid and the second plaid are moved by the same period (lattice period) or distance (s14), and the second moire interference through the lattice calculation of the first plaid and the second plaid after the movement. Generate a pattern (s16). Subsequently, a moire fringe is generated by taking the average of the first interference fringe and the second interference fringe to remove high frequency noise (S17).

Next, the phase shifted moire fringe is processed using a phase shift algorithm (s18) to generate a three-dimensional shape.

Here, the first plaid and the second plaid may be generated in various ways. For example, it may be formed by a grating. As another method, the first lattice pattern is generated by the liquid crystal display element 15 and the second lattice pattern is generated by the computer 25. The first grid pattern and the second grid pattern are calculated to form a primary moire pattern. Then, the lattice pattern is moved by the liquid crystal display element 15 and the computer 25 at the same period or at the same distance to form a secondary moire pattern. Further, by taking the average of the primary moiré pattern and the secondary moiré monet, it is possible to generate more clear moiré patterns by removing high frequency noise.

The phase map corresponding to the moiré pattern is obtained by applying a three-step phase shifting algorithm or a four-step phase shifting algorithm to the generated images. In general, the phase shift algorithm obtains a phase by taking an arc tangent to a function represented by the intensity distribution of each image. Due to the characteristics of the arc tangent function, the generated phase is limited to the range of (-π / 2) to (π / 2) or the range of (-π) to (π). Therefore, the phase map obtained by the phase shift algorithm has a discontinuous part. The phase map obtained in this step is called a wrapping phase map, and the process of connecting these discontinuous parts is called an unwrapping process.

When the phase map is multiplied by the wavelength of the moire fringe through an unwrapping process, the phase is restored to the height of the subject p (s20). As a result, the three-dimensional shape of the subject is measured (s22). Such a three-dimensional shape measurement method is disclosed in "Phase Shifting Intererometery, in Optical Shop Testing, D. Malacara, 2nd Ed. John Wiley & Sons Inc, New York 1992".

As described above, the three-dimensional shape measuring method according to the present invention provides a method for generating and phase shifting a lattice pattern simply and quickly by a liquid crystal display device and a computer, and effectively removing high frequency noise.

On the other hand, by using the three-dimensional shape measuring apparatus according to the present invention can be taken while rotating the subject (p) as shown in Figure 12 to effectively measure the shape of the subject in three dimensions. Here, in order to simplify the installation, the light source 10, the liquid crystal display element 15, and the first imaging lens 17 are installed in one housing to constitute the first unit 30, and the second imaging lens ( 18 and the image sensing device 20 may be installed in one housing to constitute the second unit 35.

Next, as illustrated in FIG. 13, a plurality of three-dimensional shape measuring apparatuses according to the present invention may be provided and installed at an appropriate position around the subject p. For example, by providing two sets of three-dimensional shape measuring apparatuses and arranging them at appropriate intervals about the subject p, it becomes possible to photograph the subject in three dimensions without having to rotate the subject p. .

Although FIG. 13 illustrates an example in which two computers 25 are provided, two sets of three-dimensional shape measuring apparatuses may be commonly used by using an interface to the computer.

As described above, the three-dimensional shape measuring method according to the present invention may apply the moire fringe generation algorithm and the phase shift algorithm to accurately and clearly measure the three-dimensional shape of the subject. The moire fringe generation algorithm according to the present invention can improve measurement accuracy as a new method capable of removing unnecessary noise while minimizing damage to measurement information, compared to existing moire fringe generation methods.

In addition, the three-dimensional shape measurement apparatus according to the present invention generates a first lattice pattern by using a liquid crystal display element, and generates a second lattice pattern by a computer to form a moire pattern, so that the three-dimensional shape can be measured simply and quickly. can do. In other words, it is possible to perform three-dimensional shape measurement very quickly because only the electrical action is possible without moving the grating mechanically for the phase shift of the moire pattern. Therefore, when photographing a person or a moving subject, it can be advantageously used.

With this arrangement, very fast and precise three-dimensional shape measurement is possible from a simplified three-dimensional measuring device.

Existing gratings are not easy to manufacture and have to move the grating mechanically in order to perform phase shifting, so that the phase shifting takes a lot of time, and the mechanical grating is limited in precision operation. On the contrary, in the measuring device according to the present invention, since the liquid crystal display element and the computer are used, the photographing speed is notably fast and the control is easy.

Furthermore, a clear three-dimensional shape can be obtained by moving the lattice pattern generated by using the liquid crystal display element and the computer by the same period to effectively remove noise.

In addition, since it is possible to photograph a three-dimensional shape using a liquid crystal display element and a computer, installation cost and installation space are small, and commercialization is possible. Furthermore, it is possible to simply photograph a human face three-dimensionally, and use the photographed image to be combined with a computer game or an education program to expand its application field.

1 is a view for explaining the principle that the moire fringe is formed.

Figure 2 shows a shadow phase transition moiré shape measuring apparatus using a conventional grid.

3 shows a conventional projection phase shift moiré shape measuring apparatus.

4 shows a conventional structured pattern projection shape measurement apparatus.

5A is a schematic configuration diagram of a three-dimensional shape measuring apparatus according to a preferred embodiment of the present invention.

5B is a view for explaining the lattice pattern formed by the liquid crystal display element employed in the three-dimensional shape measuring apparatus according to the present invention.

Fig. 6 (a) shows the first lattice pattern formed by the liquid crystal display element employed in the three-dimensional shape measuring apparatus according to the present invention, and Fig. 6 (b) shows the phase shift of the lattice pattern in Fig. 6 (a). The grid pattern after making it appear.

Fig. 6 (c) shows a second lattice pattern formed by a computer employed in the three-dimensional shape measuring apparatus according to the present invention, and Fig. 6 (d) shows the phase shift of the lattice pattern in Fig. 6 (c) after phase shifting. It shows a grid pattern.

FIG. 7 (a) is an interference fringe obtained by interfering the lattice pattern of FIG. 6 (a) and the lattice pattern of FIG. 6 (c).

FIG. 7B is an interference pattern obtained by interfering a lattice pattern of FIGS. 6A and 6D.

FIG. 7C is an interference pattern obtained by interfering a lattice pattern of FIGS. 6B and 6C.

FIG. 7 (d) is an interference fringe obtained by interfering the lattice fringes of FIGS. 6 (b) and 6 (d).

FIG. 8 (a) is a pattern obtained by combining FIGS. 7 (a) and 7 (d), and FIG. 8 (b) is a pattern obtained by combining FIGS. 7 (b) and 7 (c).

9 (a) to 9 (c) are photographs showing three phase shifted moire interference fringes.

10 (a) to 10 (c) are photographs showing four phase shifted moire interference fringes.

11 is a flowchart for explaining a three-dimensional shape measuring method according to the present invention.

12 illustrates an example of photographing a subject using a 3D shape measuring apparatus according to the present invention.

FIG. 13 shows an example in which a pair of three-dimensional shape measuring apparatuses according to the present invention is provided to photograph an object in three dimensions.

<Explanation of symbols for main parts of the drawings>

10 ... light source, 15 ... liquid crystal display element

17, 18 imaging lens, 20 image sensing element

25 Computer, p ...

Claims (7)

A light source, a liquid crystal display element disposed between the light source and the object to generate a first lattice pattern, and configured to move the first lattice pattern by electrical control, and light emitted from the light source A first image sensing element for passing through a liquid crystal display element and photographing a first lattice pattern formed on the subject; and a first image having an imaging lens disposed between the liquid crystal display element and the subject and between the subject and the image sensing element, respectively. Grid pattern generating unit; The second grid pattern is generated, the second grid pattern is moved at the same period as the first grid pattern, and the interference of the high-frequency noise is removed by the first grid pattern and the second grid pattern input from the image sensing element. Computer for generating a pattern; 3D shape measuring apparatus comprising a. The method of claim 1, A plurality of first grid pattern generating unit is provided with a three-dimensional shape measurement apparatus, characterized in that arranged around the subject at a predetermined interval. delete Generating a first lattice pattern by the liquid crystal display element; Imaging the first lattice pattern on a subject by allowing light emitted from a light source to pass through the liquid crystal display element; Generating a second plaid using a computer; Photographing the first lattice pattern and inputting the same to the computer, and multiplying the first lattice pattern by the second lattice pattern to form an interference fringe; The first lattice pattern is moved by pixel-by-pixel electrical control of the liquid crystal display device, and the second lattice pattern is moved at the same period as the first lattice pattern, thereby generating a moire pattern from which noise is removed through a lattice calculation process. Three-dimensional shape measurement method comprising a. Imaging the first grid pattern generated by the light passing through the first grid pattern on the subject; Generating a second grid pattern; Forming a first interference fringe by the first lattice and the second lattice; Moving the first grid pattern and the second grid pattern at the same period; Forming a second interference fringe by the moved first lattice and the second lattice; And removing the noise by taking the average of the first and second interference fringes. The method of claim 5, And the first lattice pattern is generated by a liquid crystal display device. The method of claim 5, And the second lattice pattern is generated by a computer.