KR20070054784A - System and method for obtaining shape and reflectance information of object surfaces from two images - Google Patents

Abstract

The present invention relates to a system and method for obtaining object surface shape and reflectance information using two images, and more particularly, to active light (light for active vision) and passive light (light for passive vision). The constructed illumination system implements phase shifting of sinusoidal pattern and approximation of hemispherical lighting, and uses it to restore phase from at least two images. A system and method for obtaining object surface shape and reflectance information using two images for acquiring surface shape information of a target object and acquiring surface reflectance information of the target object.

According to the present invention, the object surface shape and reflectance information can be obtained simultaneously based on the phase shift and hemispherical approximation illumination in two images, and the object surface can be obtained without the ON / OFF operation of the illumination source or the opening / closing operation of the illumination. Simultaneous acquisition of shape and reflectance information can further reduce constraints on lighting usage, significantly reducing surface shape data acquisition time and reflectance data acquisition time, and making high resolution data easier and faster. In other words, it can be obtained at a lower cost and increases the diversity of the fields using the phase shift technology.

Description

System and method for obtaining object surface shape and reflectance information using two images {SYSTEM AND METHOD FOR OBTAINING SHAPE AND REFLECTANCE INFORMATION OF OBJECT SURFACES FROM TWO IMAGES}

1 is a view showing a schematic configuration of an object surface shape and reflectance information acquisition system using two images of the present invention

FIG. 2 is a block diagram schematically illustrating a configuration of a shape / reflectance obtaining apparatus in an object surface shape and reflectance information obtaining system using the two images of FIG. 1.

3 is a flowchart schematically illustrating a method for obtaining object surface shape and reflectance information using two images of the present invention.

FIG. 4 is a diagram illustrating each luminance distribution curve and each pattern image of three sinusoidal phase shifts. FIG.

5 is a view showing an image captured by a camera by projecting a sine wave illumination pattern on the surface of the object;

FIG. 6 is a diagram illustrating a method of taking luminance values at two positions to restore a phase in the image of FIG. 5; FIG.

7 is a view showing a schematic configuration of an object surface shape and reflectance information acquisition system according to an embodiment of the present invention

<Description of Symbols for Main Parts of Drawings>

100: object 200: active light device

300: passive light device 400: photographing device

500: shape / reflectance acquisition device 500-1: shape restoration module

510: first brightness value calculator 520: subtractor

530: second brightness value calculator 540: inverse converter

550: multiplier 560: shape recovery unit

500-2: reflectance acquisition module 570: adder

      590: reflectance acquisition unit

The present invention relates to a system and method for obtaining object surface shape and reflectance information using two images, and more particularly, to active light (light for active vision) and passive light (light for passive vision). The constructed illumination system implements phase shifting of sinusoidal pattern and approximation of hemispherical lighting, and uses it to restore phase from at least two images. An object surface shape and reflectance information acquisition system and method using two images for acquiring surface shape information of a target object and simultaneously obtaining surface reflectance information of a target object.

In general, the appearance of an object surface is an important clue to estimating the qualitative, quantitative and structural properties of an object. Among the inherent characteristics of the object, mainly the surface shape and reflectivity determine the appearance of the object. For this reason, many studies and applications in the past have mainly used surface shape information and reflectance information, respectively, to describe the appearance of an object.

In the case of acquiring the shape and reflectance information of the real object surface, many of the studies in the past have acquired each of them independently, and even in the case of acquiring two kinds of information simultaneously, it is necessary to acquire them separately. Similar amounts of data (such as the number of images), time, amount of computation, etc. were required.

In general, a method of obtaining geometric shape information of an object surface is classified into a contact type and a non-contact type. Among these, the present invention relates to a non-contact method, and an optical method is representative of the non-contact method that does not contact the surface shape acquisition target.

Among the optical distance image (surface shape information) acquisition methods, an active vision method using a special illumination pattern is mainly used to reconstruct the distance image at high resolution.

Representative technologies of the active vision method include color-encoded structured light by K.L. Boyer et al., P.S. Huang et al.'S color fringe pattern, C. Je et al's high-contrast color-stripe pattern, J. Tajima et al.'S rainbow pattern, Adaptive color structured light from D. Caspi et al., Black / white boundary codes from O. Hall-Holt et al.

On the other hand, G. Ward's anisotropic reflectivity measurement, S.R. Image-based Bidirectional Reflectance Distribution Function (BRDF) measurements by Marschner et al. And inverse wide area illumination by Y. Yu et al.

Recently, there is an urgent need for a method for simultaneously acquiring shape and reflectance information of an object surface, and accordingly, the shape and reflectance modeling of Y. Sato et al., Korea Patent 10-0449175 "Optical two-dimensional and three-dimensional Techniques such as shape measurement system "and US patent application 20040047517" Shadow-free 3D and 2D measurement system and method ".

However, there is a limit to greatly reducing the number of data (for example, the number of images), the time, the amount of calculation, and the like even when using the above techniques. In addition, in the luminaire and the device for acquiring the shape and reflectance information, it is not based on the hemispherical illumination method for obtaining the accurate reflectance information, or more accurate information such as the on / off operation of the illumination source or the opening and closing operation of the illumination There were limitations to acquisition and broader applications.

The present invention has been made to solve the above problems, the object is a sinusoidal pattern (sinusoidal) as an illumination system consisting of active light (light for active vision) and passive light (passive light: light for passive vision) Implement phase shifting of patterns and approximate illumination of hemispherical lighting, and use them to recover phases from at least two images and obtain surface shape information of the object based on them. An object surface shape and reflectance information acquisition system and method using two images for acquiring surface reflectance information of a target object at the same time.

In addition, another object of the present invention is to obtain the surface shape and reflectance information of the object only by at least two images obtained by the illumination system composed of active and passive lighting, thereby significantly reducing the surface shape acquisition time and reflectance acquisition time 2 The present invention provides a system and method for obtaining object surface shape and reflectance information using dog images.

In addition, another object of the present invention is to use a minimum of two images obtained by the illumination system consisting of active and passive lighting to create two images that make it possible to implement high resolution data more easily, faster and at a lower cost. The present invention provides a system and method for obtaining object surface shape and reflectance information.

In addition, another object of the present invention is to enable the simultaneous acquisition of the object surface shape and reflectance information without the ON / OFF operation of the light source or the opening and closing operation of the light source, the two images to further reduce the restrictions on the use of lighting An object surface shape and reflectance information acquisition system and method are provided.

According to a first aspect of the present invention for achieving the above object, an active lighting device for projecting a sine wave pattern structured light on an object, and an unstructured light on the object At least one manual lighting device for irradiating the image, a photographing device for photographing an image of the object, and a shape / reflectance obtaining device for processing a photographed image connected to the photographing device to obtain a surface shape and reflectance; An object surface shape and reflectance information acquisition system using two images is provided.

In this case, according to an additional aspect of the present invention, the shape / reflectivity obtaining apparatus may include a first luminance value calculator for calculating first luminance values at an arbitrary position of a captured image, and the calculated first luminance values. A subtractor which performs a subtraction process on the subtractor, a second luminance value calculator which calculates second luminance values by applying a value set to the result of the subtractor, and a reciprocal process of one second luminance value of the second luminance value calculator A multiplier performing a multiplication process on the remaining second intensity value of the second intensity value calculator and the resultant value of the inverse transform unit, and restoring a phase through the result of the multiplier and using the value A shape restoring module including a shape restoring unit for acquiring shape information of the body; And

Preferably, the reflector acquiring module includes an adder for performing an addition process on the first luminous intensity values calculated by the first luminous intensity value calculating unit and a reflectance obtaining unit for obtaining reflectance information from the result of the adder.

According to an additional feature of the present invention, the at least one passive lighting device, when the passive lighting device is one, irradiates the passive lighting at an angle symmetrical with respect to the sine wave pattern structured light of the active lighting device. It is desirable to be installed in a position where it can be.

)를 갖는 정현파 패턴 구조광을 상기 능동조명장치를 통해 위상을 달리하여 2회에 걸쳐 대상물체 표면에 영사한 후 그 장면을 촬영장치로 촬영하는 제1 과정;According to a second aspect of the present invention for achieving the above object, while irradiating non-structured light to the surface of the object through a manual lighting device, a predetermined spatial frequency (

A first step of projecting a sinusoidal pattern structured light having a phase) onto the surface of an object twice by changing phases through the active lighting device, and then photographing the scene with a photographing apparatus;

A second process of obtaining two first luminance values as shown in the following equation according to a specific phase difference π at an arbitrary point of the image photographed in the first process;

A third step of performing an addition process on the two first brightness values obtained in the second step to obtain a value such as the following equation;

,

,

이다.here,

,

,

to be.

A fourth step of obtaining reflectance information of the object based on the result value calculated in the third step;

A fifth step of subtracting the two first brightness values obtained in the second step to obtain a value such as the following equation;

,

이다.here,

,

to be.

을 적용하여 하기의 식과 같은 2개의 제2 광도값들을 얻는 제6 과정;Two constant displacement values at the arbitrary points in the equation obtained in the fifth step

A sixth process of obtaining two second luminous intensity values such as the following equation;

에 대하여

의 식으로 결정되는

값이 각각

,

가 되도록 한다.Here, the two constant displacement values

about

Determined by

Each value is

,

To be

의 역수를 취해 소정의 값을 얻는 제7 과정;Obtained in the sixth step

A seventh process of taking a reciprocal of to obtain a predetermined value;

과 제7 과정에서 얻어진

의 역수값에 대하여 곱셈을 실행하여 하기의 식과 같은 값을 얻어 위상을 복원하는 제8 과정;Obtained in the sixth step

Obtained in step 7

An eighth step of performing multiplication on an inverse value of to obtain a value equal to the following equation and restoring a phase;

A ninth process of obtaining shape information of the surface of the object through geometric correction based on the obtained phase information; It provides a distance image acquisition method using a dual image comprising a.

값은 서 로 π/2 의 위상차가 나는 것이 바람직하다.In addition, according to another additional feature of the invention,

It is preferable that the values have a phase difference of π / 2.

가 일반적인 값들일 때, 상기 제6 과정에서 얻어진 2개의 제 2 광도값들에 대하여 하기의 식:Furthermore, according to another additional feature of the invention,

Are general values, the following equations for the two second luminous intensity values obtained in the sixth step:

After adding and subtracting the two values as described above, the reciprocal value is obtained by applying the seventh process to the resultant value of the addition process, and the eighth process for the reciprocal value of the addition process and the reciprocal value of the addition process. It is preferable to further include the step of obtaining the multiplication value by applying.

At this time, according to an additional feature of the present invention, it is preferable to simultaneously acquire the object surface shape and reflectance information in a state where the sine wave pattern structured light of the active lighting device and the non-structured light of the passive lighting device are irradiated together. .

The above objects and various advantages of the present invention will become more apparent from the preferred embodiments of the present invention described below with reference to the accompanying drawings by those skilled in the art.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a diagram illustrating a schematic configuration of an object surface shape and reflectance information acquisition system using two images of the present invention, and FIG. 2 is an object surface shape and reflectance information acquisition system using two images of FIG. 1. Is a block diagram schematically illustrating a configuration of a shape / reflectance obtaining apparatus, FIG. 3 is a flowchart schematically illustrating a method of obtaining object surface shape and reflectance information using two images of the present invention, and FIG. 4 is a diagram of three sinusoidal phases. 5 is a diagram illustrating each luminance distribution curve of the transition and each pattern image, and FIG. 5 illustrates an image captured by a camera by projecting a sine wave illumination pattern onto a surface of an object, and FIG. FIG. 7 is a schematic diagram of an object surface shape and reflectance information acquisition system according to an embodiment of the present invention. It shows the configuration.

Referring to FIG. 1, the object 100, an active lighting device 200 for projecting a sine wave pattern structured light onto the object 100, and the object 100. Passive illumination device 300 for irradiating unstructured-light, imaging device 400 for acquiring an image, and connected to the imaging device 400 to form a surface from the object 100 And a shape / reflectivity acquiring device 500 for acquiring reflectance information.

In this case, the active lighting apparatus 200 includes a suitable combination of a light source, an illumination pattern, a lens, a mirror, a prism, a filter, and the like.

In the active lighting device 200, the sine wave pattern structured light as shown in FIG. 4 is projected, and the sine wave pattern may be generated by various types of lighting systems such as a beam projector and a grating slide.

The manual lighting device 300 allows non-structured light to be irradiated onto the object 100.

In this case, the passive lighting device 300 is incident to at least one passive lighting at a predetermined angle in a direction different from the active lighting, thereby affecting the influence of the specular reflection component and the geometric shading component on the surface of the object 100 Reflective information of the surface of the object 100 can be accurately obtained by an approximate illumination method of the hemispherical illumination method which minimizes.

Here, when the passive light is one, it is preferable that the predetermined angle of incidence is symmetrical with the angle of incidence of the active light (see Fig. 1).

The photographing apparatus 400 may include a suitable combination of a camera, a lens, a filter, and the like.

In the present invention, when the active light and passive light is irradiated to the target object 100 from the active lighting device 200 and the passive lighting device 300, the scene is photographed by the photographing device 400. At this time, two images are acquired through the phase shift of the sine wave pattern. By this operation, an image as shown in FIG. 5 is obtained, and the shape / reflectivity obtaining apparatus 500 uses a difference in luminance values in two images to obtain a phase at each point (pixel) of the image. ) Is obtained and the surface shape of the object is obtained based on this, and the reflectance of the object is obtained using the sum of the luminance values of the two images.

)이 위 상천이에 따라 달라진다.In the general sinusoidal phase shift method, the luminance value at an arbitrary position (

This depends on the transition.

는 x 위치에서의 위상값,

는 각 위상천이에서의 천이값을 나타낸다. 여기서 3개의 미지수, a, b,

가 있으므로, 위상을 복원하기 위해서는 일반적으로 3개 이상의 식이 필요하다. 즉, 동일 위치에서 얻은 3개 이상의 위상천이 광도 정보가 필요한 것이다.Where a, b are constants, x is a positional coordinate,

Is the phase value at position x,

Represents a transition value in each phase shift. Where three unknowns, a, b,

Therefore, three or more equations are generally required to restore the phase. That is, three or more phase shift luminance information obtained at the same position is required.

The phases of three well known phase shifts can be obtained by the following equation.

이다. 이렇게 해서 일반적으로 3개 이상의 위상천이로 각각의 영상을 얻으면, 이를 통해 각 위치에서의 위상을 복원할 수 있다. 위상을 복원한 뒤에는 적절한 기하학적 보정(geometric calibration)을 통해 물체 표면의 형상 정보를 획득할 수 있다.Where the three transitions are

to be. In this way, if each image is generally obtained by three or more phase shifts, it is possible to restore the phase at each position. After reconstructing the phase, shape information on the surface of the object can be obtained through appropriate geometric calibration.

)를 갖는 정현파 패턴의 능동조명을 사용한다. 상기 정현파 패턴을 상기 대상물체(100)의 표면에 영사한 후 그 장면을 촬영장치(400)으로 촬영한다. 그 뒤, 상기 형상/반사율 획득장치(500)를 통해 상기 대상물체(100) 표면의 형상 및 반사율 정보를 획득한다.In the present invention, to restore the phase from the two images, to obtain the object surface shape and reflectance information. First, a sufficiently high spatial frequency (

Sine wave pattern with active light. The sine wave pattern is projected onto the surface of the object 100 and the scene is captured by the photographing apparatus 400. Thereafter, shape and reflectance information of the surface of the object 100 is obtained through the shape / reflectivity obtaining apparatus 500.

The configuration of the shape / reflectance obtaining apparatus 500 will be described in detail with reference to FIG. 2. Reference numeral 500-1 denotes a shape restoration module and 500-2 denotes a reflectance acquisition module.

The shape restoration module 500-1 includes a first intensity value calculator 510, a subtractor 520, a second intensity value calculator 530, an inverse transform unit 540, a multiplier 550, and a shape restorer. 560.

The first luminance value calculator 510 calculates two first luminance values at an arbitrary position x of each captured image.

The subtractor 520 subtracts the two first luminance values transmitted from the first luminance value calculator 510.

The second brightness value calculator 530 calculates two second brightness values by applying a value set to a result transmitted from the subtractor 520.

The inverse transform unit 540 performs reciprocal processing on one result transmitted from the second intensity value calculator 530.

The multiplier 550 multiplies the result of the other one transmitted from the second luminance value calculator 530 and the result of the reciprocal processing transmitted from the inverse transform unit 540.

The shape restoring unit 560 obtains the surface shape of the object by using the phase information obtained from the result transmitted from the multiplier 550.

The reflectance obtaining module 500-2 includes an adder 570 and a reflectance obtaining unit 590.

The adder 570 performs addition processing on the first luminous intensity values calculated by the first luminous intensity value calculator 510.

The reflectance obtaining unit 590 obtains reflectance information at an arbitrary position x of the object 100 from the result of the adder 570.

The operation of the object surface shape and reflectance information acquisition system using the two images according to the present invention having the above configuration will be described with reference to the flowchart of FIG. 3.

The manual lighting device 300 irradiates non-structured light to the object 100. At the same time, the active lighting apparatus 200 projects the sine wave pattern structured light to the target object 100 twice in phases. Thereafter, the photographing apparatus 400 photographs a scene to which the non-structured light and the sine wave pattern structured light are irradiated (see step S10).

Here, it is preferable that the phase difference of the sine wave pattern in the two sine wave structure light projection and imaging is π.

Subsequently, the first luminance value calculator 510 of the shape restoration module 500-1 of the shape / reflectivity obtaining apparatus 500 is based on the following Equation 1, at any position of the captured image. The first luminance values at x are calculated (see step S20).

In Equation 1, p (x) represents the increase in the luminance value by the total manual lighting at the arbitrary position x in the captured image.

Since the manual lighting device 300 is at least one or more, the p (x) can be expressed by the following equation.

Here, the number of the manual lighting apparatuses 300 is M and p _j (x) represents the increase in the brightness value at the arbitrary position x by the j-th manual lighting apparatus 300.

In the two sinusoidal structured projection and photographing, if the phase difference is π, the first intensity value calculator 510

First luminous intensity values are obtained.

Where x It can be expanded to two-dimensional coordinates.

The adder 570 performs an addition process on the two first luminance values obtained in step S20 to calculate a value as shown in Equation 2 below (see step S30).

,

,

이다.here,

,

,

to be.

와

를 같게 설정하면 경면 반사(specular reflection), 기하학적 음영(geometric shading) 및 그림자(shadow) 등의 영향을 효과적으로 감소시킬 수 있어서, 더욱 정확한 물체 표면 고유의 반사율 정보를 획득할 수 있다.At this time, in the illumination of passive light (non-structured light) and active light (structured light),

Wow

By setting the same, the effects of specular reflection, geometric shading, shadow, etc. can be effectively reduced, so that more accurate reflectance information unique to the object surface can be obtained.

The reflectance obtaining unit 590 obtains surface reflectance information of the object from the result of the adder 570 (see step S40).

The subtractor 520 subtracts the remaining value from one of two first luminance values obtained by the first luminance value calculator 510 and calculates a value as shown in Equation 3 below. )

에서 각각

으로 정의하여 산출한 식이다.Equation 3 is

Each in

It is an expression calculated by defining.

및 그 외의 바이어스 a(x) 를 제거하는 기능을 한다.As can be seen from Equation 3, the subtractor 520 increases the total brightness value due to the manual lighting device 300 so that the phase can be restored regardless of the addition and the number of unpatterned lights.

And other bias a (x) .

만큼 떨어진 위치에서의 광도값을 나타내는 아래의 수학식 4를 산출하고 미리 설정된

값 2개를 적용하여 제2 광도값들을 산출한다(S60 단계 참조).The second luminance value calculator 530 is a constant displacement small enough at the arbitrary position x based on the result value calculated by the subtractor 520 and the equation (3).

Equation 4 below, which represents the luminance value at the position separated by

The second luminance values are calculated by applying two values (see step S60).

만큼 떨어진 위치를 상기 수학식 3에 적용하면

가 되고,

가 충분히 작은 값이므로 근사(approximation)된 수학식 4가 산출된다. 이때,

이고, 형상(geometry)이나 반사특성(reflectance)이 x에서

까지의 영역에서 급격하게 변하지 않는 것으로 가정한다.Referring to the calculation process of Equation 4 in detail, the constant displacement in x

Is applied to the above equation 3

Become,

Since is a sufficiently small value, an approximated equation (4) is calculated. At this time,

Where the geometry or reflection is at x

It is assumed that it does not change drastically in the area up to.

값에 의하여

의 값이 정의되고, 상기

값을 각각

,

로 정하면 아래와 같은 제 2 광도값들을 얻을 수 있다.The preset angle

By value

Is defined, and

Each value

,

In this case, the following second luminous intensity values can be obtained.

In other words,

Get

From the above two equations, we can obtain the phase restoration equation as shown in Equation 5 below:

The phase can be easily obtained with this phase recovery equation, but the phase recovery equation with less computational quantity that can be used through specific conditions is derived as follows.

=0, -π/2 일 때, 수학식 4로부터 2개의 광도값In some cases, you can adjust the spatial frequency of the sinusoidal pattern,

When = 0 and -π / 2, two luminance values from Equation 4

와

Wow

You get

The inverse transformer 540 obtains a predetermined value by taking an inverse of one of the values transmitted from the second luminance value calculator 530 (see step S70).

를 획득한다.In other words,

Acquire.

값들에 대한 위상복원 등식인 상기 수학식 5를 적용하는 경우에는 상기 제2 광도값 산출부(530)로부터 산출된 상기 2개의 제 2 광도값들에 대하여 가산처리를 행한 후 상기 역변환부(540)을 이용하여 상기 가산처리의 결과값에 대하여 역수값을 얻는다.At this time, a general having an arbitrary phase difference

When the equation (5), which is a phase restoration equation for the values, is applied, the inverse transform unit 540 performs an addition process on the two second luminance values calculated by the second luminance value calculator 530. Is used to obtain the reciprocal value of the result of the addition process.

The multiplier 550 multiplies the other of the values transmitted from the second brightness value calculator 530 by the inverse of one second brightness value transmitted from the inverse converter 540 and the following equation (6) The phase recovery is performed by obtaining a value of the phase recovery equation having a small amount of the same calculation amount (see step S80).

값들에 대한 위상복원 등식인 상기 수학식 5를 적용하는 경우에는 상기 제2 광도값 산출부(530)로부터 산출된 상기 2개의 제 2 광도값들에 대하여 감산처리를 행한 후 상기 곱셈기(550)을 이용하여 상기 감산처리의 결과값 및 상기 역변환부(540)로부터 산출된 상기 2개의 제 2 광도값들에 대한 가산처리의 역수값에 대하여 곱셈값을 얻게되고, 그 곱셈값을 이용하여 위상을 복원한다.At this time, a general having an arbitrary phase difference

In the case of applying Equation 5, which is a phase restoration equation for the values, the multiplier 550 is subtracted after subtracting the two second luminance values calculated by the second luminance value calculator 530. A multiplication value is obtained for the result value of the subtraction process and the inverse value of the addition process for the two second luminance values calculated from the inverse transform unit 540, and the phase is restored using the multiplication value. do.

가 되어 상기 수학식 6이 얻어진다.In other words,

Equation 6 is obtained.

Thereafter, the shape restoring unit 560 obtains the surface shape of the object 100 by performing geometric correction based on the phase information obtained from the result transmitted from the multiplier 550 (see step S90).

An object surface shape and reflectance information acquisition system according to an embodiment of the present invention will be described with reference to FIG.

The object surface shape and reflectance information acquisition system of the embodiment includes a target object 100, one active lighting device 200, a plurality of passive lighting devices 300, a photographing device 400, and a shape / reflectance obtaining device ( 500).

Here, the sine wave pattern structured light by the active lighting device 200 and the plurality of unstructured light by the passive lighting devices 300 evenly arranged at uniform intervals. Because of the lights, hemispherical lighting is approximated.

According to the object surface shape and reflectance information acquisition system and method using the two images according to the present invention, the object surface shape and active lighting device 200 and passive lighting device 300 according to the use of the active lighting device 200 The reflectance information according to the use of) can be obtained simultaneously without time difference.

Therefore, the object surface in the state in which the sine wave pattern structured light of the active lighting device 200 and the non-structured light of the passive lighting device 300 are irradiated simultaneously without the ON / OFF operation of the illumination source or the opening / closing operation of the illumination. Simultaneous acquisition of shape and reflectance information further reduces constraints on lighting use.

The present invention is not limited to the embodiments described above, and various modifications and changes can be made by those skilled in the art, which are included in the spirit and scope of the present invention as defined in the appended claims.

For example, the phase restoration method proposed in the present invention and the surface shape obtained through the present invention can also be applied to an interferometer in which two or more sinusoidal patterns overlap. In addition, for more accurate phase and surface shape acquisition, two or more phase or surface shape data are acquired through variation of some of the lighting components, the camera components, and the object, and based on this, more accurate phase or surface shape acquisition is obtained. This is possible.

As described above, if the object surface shape and reflectance information acquisition system and method using the two images according to the present invention is applied, the illumination consisting of active and passive illumination irradiated together without the need of the ON / OFF operation or opening and closing operation Based on the phase shift in at least two images acquired by the system, it is possible to simultaneously acquire object surface shape information and object surface reflectance information through phase restoration.

In addition, according to this, there is an effect that can significantly reduce the time, cost, data amount, calculation amount, etc. required for surface shape acquisition and surface reflectance acquisition.

In addition, there is an effect that makes it possible to implement high-resolution surface shape and reflectance data more easily, at higher speeds, and at less cost.

In addition, accordingly, there is an effect of expanding the field of application of surface shape and reflectance data.

Claims (7)

An active lighting device for projecting sinusoidal patterned structured light onto an object, at least one passive lighting device for irradiating unstructured light onto the object, and Object surface shape and reflectance using two images comprising a photographing apparatus for photographing an image, and a shape / reflectivity obtaining apparatus for obtaining a surface shape and reflectance by processing the photographed image connected to the photographing apparatus Information acquisition system. The method of claim 1, The shape / reflectivity obtaining apparatus includes: a first luminance value calculator for calculating first luminance values at an arbitrary position of a photographed image, a subtractor for performing a subtraction process on the calculated first luminance values, and the subtractor; A second luminous intensity calculating unit configured to calculate second luminous intensity values by applying a value set to a result of?, An inverse converting unit performing reciprocal processing on one second luminous intensity value of the second luminous intensity value calculating unit, and the second luminous intensity value A multiplier for performing a multiplication process on the remaining second intensity value of the calculator and a result value of the inverse transform unit, and a shape restorer for restoring a phase through the multiplier result and using the value to obtain shape information of the object. Configured shape restoration module; And A reflectance obtaining module comprising an adder for performing an addition process on the first luminous intensity values calculated from the first luminous intensity value calculating unit and a reflectance obtaining unit for obtaining reflectance information from the result of the adder; System surface shape and reflectance information acquisition system using two images, characterized in that configured to include. The method of claim 1, The at least one passive lighting device is installed at a position where the passive lighting can be irradiated at an angle symmetrical with respect to the sine wave pattern structured light of the active lighting device when the passive lighting device is one. Object surface shape and reflectance information acquisition system using two images. While irradiating non-structured light onto the surface of the object through a manual lighting device, a predetermined spatial frequency (

A first step of projecting a sinusoidal pattern structured light having a phase) onto the surface of an object twice by changing phases through the active lighting device, and then photographing the scene with a photographing apparatus; A second process of obtaining two first luminance values as shown in the following equation according to a specific phase difference π at an arbitrary point of the image photographed in the first process;

A third step of performing an addition process on the two first brightness values obtained in the second step to obtain a value such as the following equation;

here,

,

,

to be. A fourth step of obtaining reflectance information of the object based on the result value calculated in the third step; A fifth step of subtracting the two first brightness values obtained in the second step to obtain a value such as the following equation;

here,

,

to be. Two constant displacement values at the arbitrary points in the equation obtained in the fifth step

A sixth process of obtaining two second luminous intensity values such as the following equation;

Here, the two constant displacement values

about

Determined by

Each value is

,

To be Obtained in the sixth step

A seventh process of taking a reciprocal of to obtain a predetermined value; Obtained in the sixth step

Obtained in step 7

An eighth step of performing multiplication on an inverse value of to obtain a value equal to the following equation and restoring a phase;

A ninth process of obtaining shape information of the surface of the object through geometric correction based on the obtained phase information; Object surface shape and reflectance information acquisition method using the two images, characterized in that comprises a. The method of claim 4, wherein Two set

A method of obtaining object surface shape and reflectance information using two images, in which values are out of phase with each other by π / 2. The method of claim 4, wherein

Are general values, the following equations for the two second luminous intensity values obtained in the sixth step:

After adding and subtracting the two values as described above, the reciprocal value is obtained by applying the seventh process to the resultant value of the addition process, and the eighth process for the reciprocal value of the addition process and the inverse value of the addition process. Obtaining the product surface shape and reflectance information using the two images, further comprising the step of obtaining the multiplication value by applying. The method of claim 4, wherein Object surface shape and reflectance using two images, wherein the object surface shape and reflectance information are simultaneously acquired while the sinusoidal pattern structured light of the active lighting device and the non-structured light of the passive lighting device are irradiated together. How to get information.

Images