KR100585270B1 - System and method for obtaining shape and color information of object surfaces from two images - Google Patents

Abstract

The present invention is a lighting system composed of active light (light for active vision) and passive light (passive light: light for passive vision) phase shifting and hemispherical lighting (sinusoidal pattern) lighting, which is used to restore the phase from at least two images and to obtain the surface shape information of the target object and to obtain the surface color information of the target object. As related to the object surface shape and color information acquisition system and method,

According to the present invention, the object surface shape and color 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 color information further reduces constraints on lighting usage, dramatically reducing surface shape data acquisition time and color 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.

Structured Light, Phase Shift, Sinusoidal, Measurement, Distance Image, Phase Restoration, 3D

Description

System surface and color information acquisition system and method using two images {SYSTEM AND METHOD FOR OBTAINING SHAPE AND COLOR INFORMATION OF OBJECT SURFACES FROM TWO IMAGES}

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

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

3 is a flowchart schematically illustrating a method for obtaining object surface shape and color 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 color 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: multi-channel recording device

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

500-2: color acquisition module 510: first luminance value calculator

520: subtractor 530: second brightness value calculator

540: inverse transform unit 550: multiplier

560: shape restorer 570: adder

590: color acquisition unit

The present invention relates to a system and method for acquiring an object surface shape and color information using two images, and more particularly, to active light (active light) and passive light (light for passive vision). The constructed illumination system implements the phase shifting of the sinusoidal pattern and the approximate illumination of the hemispherical lighting, and uses it to restore the phase from at least two images. The present invention relates to an object surface shape and color information acquisition system and method using two images for acquiring color information from the surface of an object by obtaining a surface shape of the object and extracting increments of luminance values according to color channels. .

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 intrinsic properties of an object, the surface shape and reflectance mainly 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 a study of acquiring two kinds of information simultaneously, it is necessary to acquire them separately. The number of data (such as the number of images), the time, the amount of calculation, and the like that were similar to the amount of data needed were required.

In general, the method of obtaining the surface geometry is divided into contact and contactless. 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 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 ".

The method of obtaining reflectance information on the surface of an object can be divided into two types according to the obtained information.

The first is a case of obtaining surface reflectance information of a short channel (black and white, grayscale), the second is a case of obtaining surface reflectance information of a multi-channel (color).

By the way, the technology for acquiring the short channel surface reflectance information simultaneously with the shape of the object surface has already been advanced in many industrial applications, but the technology for acquiring the multi-channel surface reflectance information simultaneously with the object surface shape is still the industrial application. It is in the very early stages.

Therefore, it is difficult to reduce the number of images and processing time required for data acquisition according to the industrial needs only by simultaneously acquiring the object surface shape and the short channel surface reflectance information, but color (multi-channel surface reflectance) information together with the shape information. Simultaneously acquiring the problem may cause additional constraints in the implementation and increase the number of images and processing time required for data acquisition.

In addition, in the luminaire and the device for acquiring the shape and color information, it is not based on the hemispherical illumination method for acquiring accurate color information, or more accurate information such as the on / off operation of the illumination source or the opening / 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 sine wave pattern (sinusoidal) as an illumination system consisting of active light (light for active vision) and 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 color information acquisition system and method using two images for acquiring surface color information of a target object at the same time.

In addition, another object of the present invention is to acquire the surface shape and color information of the object only by at least two images obtained by the illumination system consisting of active and passive lighting, it is possible to drastically reduce the surface shape acquisition time and color information acquisition time An object surface shape and color information acquisition system and method using two 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. An object surface shape and color information obtaining apparatus and method used.

In addition, another object of the present invention is to provide two images that can further reduce the restrictions on the use of the light as it is possible to simultaneously acquire the object surface shape and color information without the ON / OFF operation of the light source or the opening and closing of the light source. An object surface shape and color information acquisition system and method are used.

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 multi-channel photographing apparatus for capturing an image of the object, and having a plurality of color channels, and a photographed image connected to the multi-channel photographing apparatus to process a surface shape and color An object surface shape and color information acquisition system using two images, comprising a shape / color acquisition device for acquiring information.

In this case, according to an additional feature of the present invention, the shape / color obtaining apparatus may include a first luminance value calculator which calculates 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 An inverse transform unit for performing a multiplication process, a multiplier performing a multiplication process on the remaining second intensity value of the second intensity value calculator and a result value of the inverse transform unit, and restoring a phase through the result of the multiplier and using the value A shape restoration module comprising a shape restoring unit for acquiring shape information of the body; And

Preferably, the color acquisition module comprises an adder for performing an addition process on the first luminous intensity values calculated from the first luminous intensity value calculator and a color acquiring unit for acquiring color 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 상기 다채널 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) through the active lighting device onto the surface of the object two times with different phases and then capturing the scene with the multi-channel imaging device;

에 따라 하기의 식과 같은 2개의 제1 광도값들을 얻는 제2 과정; Specific phase difference at any point of the image captured in the first process

A second process of obtaining two first luminance values according to the following equation;

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 acquiring color 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 식을 얻어 위상을 복원하는 제8 과정;Obtained in the sixth step

Obtained in step 7

An eighth step of performing multiplication on the inverse value of to obtain the following equation to restore the phase;

A method of obtaining object surface shape and color information using two images, comprising a ninth process of acquiring surface shape information of a target object through geometric correction based on the obtained phase information.

값은 서로 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 with each other.

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.

In this case, according to an additional feature of the present invention, it is preferable to simultaneously acquire the object surface shape and color 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 color information acquisition system using two images of the present invention, and FIG. 2 is an object surface shape and color information acquisition system using two images of FIG. 1. FIG. 3 is a block diagram schematically showing the configuration of a shape / color obtaining apparatus, and FIG. 3 is a diagram showing a schematic configuration of an object surface shape and color information obtaining system according to an embodiment of the present invention, and FIG. FIG. 5 is a flowchart illustrating a method of obtaining object surface shape and color information using dog images, and FIG. 5 is a diagram illustrating luminosity distribution curves and three pattern images of three sinusoidal phase shifts, and FIG. FIG. 7 is a view showing an image captured by a camera by projecting onto an object surface, and FIG. 7 shows light intensity at two positions in order to restore a phase in the image of FIG. It is a figure which shows the method of taking a value.

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. The target object is connected to a passive lighting device 300 for unstructured-light irradiation, a multi-channel imaging device 400 for acquiring a multi-channel image, and the multi-channel imaging device 400. A shape / color acquisition device 500 for acquiring surface shape and color information from 100 is provided.

In this case, the active lighting device 200 includes a suitable combination of a light source, a light 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. 5 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 It is possible to accurately obtain the color information of the surface of the object 100 by the approximate illumination method of the hemispherical illumination method to minimize.

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 multichannel photographing apparatus 400 may include a suitable combination of a multichannel 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 multi-channel imaging device 400 captures the scene. 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. 6 is obtained, and the shape / color acquisition device 500 uses a difference in luminance values in two images to obtain a phase at each point (pixel) of the image. ) And obtain the surface shape of the target object based on this, and obtain the color information of the target object using the sum of the luminance values of the two images.

)이 위상천이에 따라 달라진다.In a typical sinusoidal phase shift method, as shown in FIG.

) Depends on the phase shift.

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 물체표면의 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 상기 다채널 촬영장치(400)으로 촬영한다. 그 뒤, 상기 형상/컬러획득 장치(500)를 통해 상기 대상물체(100) 표면의 형상 및 컬러 정보를 획득한다.In the present invention, to restore the phase from the two images, to obtain the object surface shape and color 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 multi-channel imaging apparatus 400. Thereafter, shape and color information of the surface of the object 100 is obtained through the shape / color obtaining apparatus 500.

Referring to the accompanying drawings, the configuration of the image restoration / color acquisition 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 color acquisition module.

The image restoration module 500-1 may include a first luminance value calculator 510, a subtractor 520, a second luminance value calculator 530, an inverse transformer 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 color acquisition module 500-2 includes an adder 570 and a color acquirer 590.

The adder 570 performs an addition process on the first luminance values calculated by the first luminance value calculator 510.

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

 An operation of the object surface shape and color information acquisition system using 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 the target object 100 with non-structured light. At the same time, the active lighting device 200 projects the sine wave pattern illumination to the target object 100 twice in phases. Thereafter, the multi-channel imaging apparatus 400 captures a scene to which the non-structured light and the sine wave pattern structured light are irradiated (see step S10).

인 것이 바람직하다.Here, the phase difference of the sine wave pattern in the two sine wave structure light projection and photographing

Is preferably.

 Thereafter, the first luminance value calculator 510 of the shape restoration module 500-1 of the shape / color obtaining apparatus 500 may have an arbitrary position x of each image photographed based on Equation 1 below. Calculate the first luminous intensity values in (see step S20).

In Equation 1, P (x) represents an increase in total luminance value at the arbitrary position x of the image photographed by the multi-channel imaging apparatus 400.

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 Pj (x) represents the increase in the brightness value at the arbitrary position x by the j-th manual lighting apparatus 300.

Therefore, when the phase difference between the sinusoidal patterns is π, the first intensity value calculator 510

First luminous intensity values are obtained.

로 두면 이차원 좌표로 확장이 가능하다.Where x

If set to 2D, 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.

Here, the sum of the two luminous intensity values of Equation 2 becomes a value irrelevant to the phase value, and as a result, is not influenced by the pattern of the sine wave structure light, resulting in a uniform illumination as a whole. In addition, if the passive light (unstructured light) and one active light (structured light) have an approximate structure of hemispherical illumination, specular reflection, geometric shading, shadow, etc. Since the influence can be effectively reduced, more accurate color information unique to the object surface can be obtained (see step S40).

라 두면, 하기의 등식이 성립한다:When using a camera having a total of Q channels, image brightness information of a total of Q channels can be obtained. The sum of the luminance values of the first and second images for the kth channel

In other words, the following equation holds:

For example, if the multi-channel imaging apparatus 400 has three RGB color channels, the RGB three color channels are applied to Equation 3, and the following equation is calculated.

는 각각 빨강(Red), 초록(Green), 파랑(Blue)채널에 대한 값임을 의미한다.Where index

Means values for Red, Green, and Blue channels, respectively.

According to Equation 4, it can be seen that luminance values irrespective of the phase of the sine wave can be obtained for each color channel, and color information of the object surface can be estimated using these luminance values.

Theoretically, assuming that a single sensor observes a single point on the surface of the object, the entire solid angle of the hemisphere is centered around the observation point on the surface of the object and centered on a straight line through that point and the sensor location. When light of uniform illumination is incident on an angle, an image captured by the sensor reflects an inherent color that is not affected by specular reflection or geometric shading coefficient of an object surface. It is practically impossible to make a completely ideal hemispherical illumination incident on the entire surface of any object.

Therefore, in order to restore the intrinsic color of the exact object surface, it is common to use a method of illumination close to hemispherical lighting.

In the present invention, the illumination system of the method of irradiating the surface of the object with at least two lights at different angles, including the sinusoidal structured light, and preferably a form close to the hemispherical light, so that a greater number of lights Take different forms of illumination on the surface of the object (see Figure 7).

와

를 같게 설정하고, 입사되는 방향이 카메라의 촬영방향축을 중심으로 서로 대칭이 되게 두면 경면 반사(specular reflection), 기하학적 음영(geometric shading) 및 그림자(shadow) 등의 영향을 효과적으로 감소시킬 수 있어서, 비교적 정확한 물체 표면 고유의 컬러 정보를 획득할 수 있다.For example, if one nonstructural light passive light is added in addition to the sinusoidal structured light active light,

Wow

And the incident directions are symmetrical with respect to the camera's shooting direction axis, effectively reducing the effects of specular reflection, geometric shading, and shadow, so that Accurate object surface color information can be obtained.

In addition, by using a larger number of additional manual lights, when a plurality of lights including sinusoidal patterns are evenly arranged at various angles, preferably at evenly spaced angles, and incident on the surface of an object, The effect is approximately equivalent to hemispherical lighting.

Therefore, when a sufficient number of manual lights are additionally used, the effects of specular reflection, geometric shading, and shadows can be minimized to obtain extremely accurate color information unique to the object surface. can do.

The subtractor 520 subtracts the remaining value from one of the two first luminance values obtained by the first luminance value calculator 510 to calculate a value as shown in Equation 5 below. Reference)

에서

로 정의하여 산출된 값이다.Equation 5 is

in

It is calculated by defining.

As can be seen in Equation 5, the subtractor 520 is used as the manual lighting apparatus 300 to restore the phase irrespective of whether or not to add a patternless illumination.

그 외의 바이어스

를 제거하는 기능을 한다.Increased overall brightness

Other bias

To function.

만큼 떨어진 위치에서의 광도값을 나타내는 아래의 수학식 6을 산출하고 미리 설정된

값 2개를 적용하여 제2 광도값들을 산출한다.(S60 단계 참조)The second brightness value calculator 530 has a sufficiently small constant displacement at the arbitrary position x based on Equation 5 calculated by the subtractor 520.

Equation 6 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 5에 적용하여

가 되고,

가 충분히 작은 값이므로 근사(approximation)된 수학식 6이 산출된다. 이때,

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

까지의 영역에서 급격하게 변하지 않는 것으로 가정한다.Referring to the calculation process of Equation 6 in detail, a constant displacement in x

By applying a position separated by

Become,

Since is a sufficiently small value, an approximated equation (6) 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

로 두면 아래와 같은 제2 광도값들을 얻을 수 있다.The preset angle

By value

Is defined, and

Value

By setting the second luminance values as follows.

In other words,

Get

From the above two equations, we can obtain the phase recovery equation as shown in Equation 7 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.

일 때, 수학식 6로부터 2개의 광도값In some cases, you can adjust the spatial frequency of the sinusoidal pattern,

When two luminance values from Equation 6

You get

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

를 획득한다.In other words,

Acquire.

값들에 대한 위상복원 등식인 상기 수학식 7를 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 (7), 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 reciprocal of one second luminous intensity value transmitted from the inverse transform unit 540 by the remaining second luminous intensity value transmitted from the second luminous intensity value calculation unit 530. The phase recovery equation recovers the phase by obtaining a value of a phase recovery equation with a small amount of computation (see step S80).

값들에 대한 위상복원 등식인 상기 수학식 7를 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

When the equation (7), which is a phase restoration equation for the values, is applied, 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 8이 얻어진다.In other words,

Equation 8 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 transmitted from the multiplier 550 (see step S90).

In this way, it is possible to obtain surface shape information by the luminance values of individual channels from the multichannel image acquired by the multichannel imaging device, and more accurate shape information can be obtained based on the shape data of the individual channels thus obtained. Do.

In addition, when using a camera having a total of Q channels, it is possible to obtain the surface shape information in the same manner as described above after converting the image luminance information of the total Q channels into a single luminance image. In this case, the average image luminance of the newly defined Q channels is given by the following equation:

For example, for the RGB three color channels, the following equation is used:

An object surface shape and color information acquisition system according to an embodiment of the present invention will be described with reference to FIG. 7.

The object surface shape and color information acquisition system of the embodiment includes a target object 100, one active lighting device 200, a plurality of passive lighting devices 300, a multi-channel imaging device 400 and a shape / color acquisition. 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 color information acquisition system and method using the two images according to the present invention, the object surface shape and the active lighting device 200 and passive lighting device 300 according to the use of the active lighting device 200 The color information according to the use of) can be obtained at the same time 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 color information further reduces the constraints on lighting usage.

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 may be acquired through variation of all lighting components, all camera components, and some of the objects, and based on this, more accurate phase or surface shape acquisition may be obtained. It is possible.

As described above, if the object surface shape and color 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 the object surface shape information and the object surface color information through phase restoration.

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

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

In addition, accordingly, there is an effect of expanding the field of application of the surface shape and surface color 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 And a shape / color acquisition device that captures an image and has a plurality of color channels, and a shape / color acquisition device that acquires surface shape and color information by processing the captured image connected to the multichannel imaging device. Object surface shape and color information acquisition system using two images. The method of claim 1, The shape / color 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 transform unit performing inverse processing to 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 result of the multiplier and using the value Configured shape restoration module; And And a color acquisition module including an adder for performing an addition process on the first luminous intensity values calculated from the first luminous intensity value calculating unit and a color obtaining unit for obtaining color information from the result of the adder. Object surface shape and color information acquisition system using two images. 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 color information acquisition system using two images. While irradiating non-structured light on the object surface through a manual lighting device, Predetermined spatial frequency (

A first step of projecting a sinusoidal pattern structured light having a phase) onto a surface of an object two times by changing phases through an active lighting device and capturing the scene with a multi-channel imaging device; Specific phase difference at any point of the image captured in the first process

A second process of obtaining two first luminance values according to the following equation;

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 acquiring color 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 the inverse value of to obtain the following equation to restore the phase;

And a ninth process of acquiring surface shape information of the target object through geometric correction based on the obtained phase information. 2. The method of claim 4, wherein Two set

A method of obtaining object surface shape and color information using two images, wherein values are in phase difference of π / 2 from each other. 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 reciprocal value of the addition process. And obtaining the multiplication value by applying the method. 2. The method of claim 4, wherein Object surface shape and color using two images, wherein the object surface shape and color 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.

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