KR101624120B1 - System and method for illuminating pattern light of structured light for measuring 3d forming - Google Patents

Abstract

The present invention relates to an apparatus and a method to emit pattern light of structured light to a local area to measure a three dimensional shape and, more specifically, relates to a system and the method to emit pattern light of structured light to a local area to measure a three dimensional shape which uses only one camera and one beam projector to reconstruct the three dimensional image without an additional device in a field where a variety of reflectivity exists and precise three-dimensional photographing is required. The system to emit pattern light of structured light to a local area to measure the three dimensional shape comprises: one beam projector unit (100) to emit light to a measurement target (10); a camera unit (200) to photograph an image of the measurement target (10) to which the light is emitted; and a control unit (300) to control the beam projector unit (100) to adjust a brightness in accordance with a local position of the measurement target (10).

Description

TECHNICAL FIELD [0001] The present invention relates to a system and method for illuminating a pattern light source for a local region of a structure light for three-dimensional shape measurement,

Field of the Invention The present invention relates to a method and apparatus for irradiating a pattern light source for a local area of a three-dimensional shape measuring structural light, and more particularly, And more particularly, to a system and method for irradiating a pattern light source for a local area of structured light for three-dimensional shape measurement, which can be reconstructed into three-dimensional images using only one of the projectors.

The structural optical system is a system that reconstructs an active light source (beam projector) from 2D camera to 3D information by interpreting it as depth information. In other words, the structured optical system is to reconstruct three-dimensional information by encoding the corresponding points in the three-dimensional space with one or more cameras using one active beam project part (beam projector or line laser). Since active systems such as structured light actively detect the corresponding points of space, they have a stronger spatial resolution than passive stereo cameras, and real-time processing is possible according to pattern design.

Also, the reliability of three-dimensional data in a structural optical camera system is influenced by various factors such as pattern shape, camera performance, and beam projector performance, but the data acquired by the camera is most important.

However, the stereoscopic camera for constructing such a three-dimensional camera must match the correspondence to the casting of two cameras, so that accurate three-dimensional modeling is possible, but it is difficult to detect the corresponding point.

In addition, since the performance of the beam projector is excellent, if patterns are not accurately obtained from the viewpoint of a camera even if various patterns are irradiated onto the target object, it is difficult to restore highly reliable three-dimensional data due to the characteristics of the active system.

Also, even though the performance of the camera and the beam projector is excellent, since the refractive index, the reflectance, and the transmittance depend on the wavelength depending on the medium of the target object, there is a difficulty in obtaining accurate patterns from the camera.

Particularly, when inspecting PCB boards in the field of industrial inspection, there is a tendency that a chip having a low reflectance (black color series), a metal body having high reflectance (lead, electric current flowing pattern), a normal reflectance Surface, etc.), taking a degree of exposure globally as a single factor in the camera's perspective, will result in various errors.

For example, matching a global exposure to a metal body reduces the amount of light received as a whole, making it impossible to measure dark-colored areas that do not absorb and reflect most of the light. Conversely, when the exposure is adjusted to a dark color system, saturation occurs at a portion where strong reflection occurs, such as a metal body, which also makes it impossible to measure in three dimensions.

In order to solve this problem, Korean Patent No. 10-0914961 ("Optimal Exposure Determination Method and System of 3D Camera", registered Aug. 25, 2009) tried to solve the problem by adjusting the exposure of the camera, The problem is not completely solved by the exposure value of the phosphor.

Korean Patent No. 10-0914961 ("Method and system for determining optimum exposure of a three-dimensional camera ", filed on Aug. 25, 2009).

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide a three-dimensional And to provide a system and method for illuminating a pattern light source for a local area of a structure light for three-dimensional shape measurement that can be reconstructed into an image.

The present invention relates to a pattern light source illumination system for a local area of a structure light for three-dimensional shape measurement, comprising a beam project part (100) for irradiating a light source with a measurement object (10); A camera unit (200) for capturing an image of the measurement object (10) irradiated with the light source; A control unit 300 for controlling the beam project unit 100 to adjust the brightness according to a local position of the measurement object 10; And a control unit.

The controller 300 includes a pattern generator 310 for generating a pattern on a light source of the beam projector 100, A coordinate system analyzer 320 for generating coordinates on the image of the camera unit 200; A pattern control unit 330 for matching the pattern of the beam project unit 100 with the coordinates of the camera unit 200; A pattern analyzer 340 for adjusting the brightness of coordinates of the beam project unit 100 corresponding to the coordinates of the image photographed by the camera unit 200 in the pattern and coordinate matched data; A three-dimensional rendering unit 350 for reconstructing the brightness-adjusted image into a three-dimensional image; And a control unit.

The pattern analyzer 330 extracts the saturation region when the saturation region of the light intensity exists in the data in which the pattern and the coordinates match each other and extracts the saturated region from the coordinates of the image of the camera unit 200 to the saturation region And the brightness of the corresponding coordinates of the beam project unit 100 is reduced to a previously stored standard brightness value.

When the pattern intensity and the coordinate data are less than the previously stored standard brightness value, the pattern analyzing unit 330 may determine that the brightness of the image is less than the standard brightness value stored in the coordinates of the image of the camera unit 200 The brightness of the coordinates of the beam projecting unit 100 corresponding to the low region is increased to a previously stored standard brightness value.

On the other hand, the method of irradiating the pattern light source for the local area of the three-dimensional shape measuring structural light of the present invention includes a white light irradiation step (S100) for irradiating white light to the measurement object 10 using the beam project part 100; An image capturing step (S200) of capturing the measurement object (10) irradiated with the white light using the camera unit (200); A brightness distribution modeling step S300 for modeling the brightness distribution of the image obtained by the camera unit 200; A pattern irradiating step (S400) of irradiating a light source of a pattern shape to the measurement object (10) using the beam project part (100); A light intensity extracting step (S500) of photographing an image of the measurement object (10) irradiated with the pattern-shaped light source and extracting light intensity of each pattern region in the image; A light intensity control step S600 for adjusting the light intensity of each region of each pattern extracted in the light intensity extraction step S400; And a three-dimensional reconstruction step (S700) of reconstructing the three-dimensional image after acquiring the image in which the light intensity of each pattern is adjusted for each region; .

The pattern irradiating step S400 may include generating coordinates on the image of the measurement object 10 acquired by the camera unit 200 and matching the pattern irradiated through the beam project unit 100 with the coordinates .

In the light intensity control step S600, when the light intensity of each region extracted in the light intensity extraction step S500 exists in a region corresponding to the saturation region, The brightness of the saturation region with respect to the coordinates of the corresponding beam projecting unit 100 is reduced to a previously stored standard brightness value.

In the light intensity control step S500, when the light intensity among the light intensities of the respective regions extracted in the light intensity extraction step S500 is less than the previously stored standard brightness value, The brightness of the coordinates of the beam project unit 100 corresponding to the pre-stored standard brightness value is increased to the pre-stored standard brightness value.

As described above, the present invention relates to a system and method for irradiating a pattern light source for a local area of a three-dimensional shape measuring structural light, and more particularly, It is possible to reconstruct three-dimensional images using only one projector each.

1 is a conceptual diagram of a pattern light source illuminating system for a local region of a three-dimensional shape measuring structural light according to the present invention
FIG. 2 is a diagram showing a configuration of a pattern light source illuminating system for a local region of a three-dimensional shape measuring structured light according to the present invention
FIG. 3 is a front and rear photographs of a three-dimensional image reconstructed by a pattern light source illuminating system for a local region of the three-dimensional shape measuring light beam according to the present invention
4 is a flowchart of a method of irradiating a pattern light source for a local region of a three-dimensional shape measuring structural light according to the present invention

Hereinafter, the technical idea of the present invention will be described more specifically with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are included to provide a further understanding of the technical concept of the present invention, are incorporated in and constitute a part of the specification, and are not intended to limit the scope of the present invention.

FIG. 1 is a conceptual diagram of a pattern light source illuminating system for a three-dimensional shape measuring structural light according to the present invention, and FIG. 2 is a structural diagram of a pattern light source illuminating system for a three- .

The present invention relates to a pattern light source illuminating system for a local area of a structure light for three-dimensional shape measurement, and comprises a beam project unit 100, a camera unit 200 and a control unit 300.

The beam project part 100 serves to irradiate the light source with the measurement object 10. That is, the beam projecting unit 100 irradiates the measurement object 10 with a light source in the form of white light or a pattern.

The camera unit 200 acquires (captures) an image of the measurement object 10 irradiated with the light source. At this time, the camera unit 200 uses a general camera, and the lens of the camera is automatically or manually adjusted by the controller 300.

The control unit 300 controls the beam project unit 100 to adjust the brightness according to the local position of the measurement object 10. That is, the control unit 300 controls the beam project unit 100 so that a uniform light source can be irradiated to the camera unit 200. At this time, the light amount according to the local position of the measurement object 10 is adjusted by the controller 300 in the beam project part 100. Also, the controller 300 can be used as an apparatus such as a computer, and can adjust the focal point of the camera, the diaphragm, and the local brightness of the beam project unit 100.

The controller 300 includes a pattern generator 310, a coordinate system analyzer 320, a pattern controller 330, a pattern analyzer 340, and a 3D rendering unit 340. [ (350).

The beam project unit 100, the camera unit 200, and the pattern control unit 300 may be configured as a module in a separate PC environment in a separate configuration. The beam project unit 100, the camera unit 200 and the pattern control unit 300 may be driven by a single board. In addition, the beam project unit 100 and the pattern control unit 300 may be embodied, and the camera may be driven by a separate camera such as a webcam, a digital camera, or a cctv.

The pattern generator 310 generates a pattern in the light source of the beam projector 100. In more detail, the beam projecting unit 100 irradiates the light source of white light to the measurement object 10. The white light of the beam projecting unit 100 is irradiated with the light source in a pattern form by the pattern generating unit 310.

Also, in the case of a pattern, the pattern generator 310 may read the pattern picture file stored in advance or generate a pattern necessary for the situation, and irradiate the pattern to the measurement object 10.

In addition, the motor can control a pattern that is stored in advance, such as a projector, so that a white light source can be inspected as a pattern.

When examining a pattern in any of the above cases, it is possible to acquire a uniform light source having no saturation from the camera viewpoint by considering the pattern of the corresponding sequence and the weighted value previously modeled.

The coordinate system analyzing unit 320 generates coordinates on the image of the camera unit 200 that has taken the measurement object 10.

The pattern control unit 330 matches the coordinates of the pattern-shaped light source irradiated by the beam project unit 100 and the image obtained by the camera unit 200 with each other. That is, the pattern control unit 330 models corresponding points of the beam project sub-coordinates corresponding to the camera coordinates.

The pattern analyzer 330 adjusts the brightness of the coordinates of the beam project unit 100 corresponding to the coordinates of the image photographed by the camera unit 200 on the data in which the pattern and the coordinates match. More specifically, when there is light intensity (saturation region) among the regions corresponding to the coordinates of the image photographed by the camera unit 200, the light intensity of the saturation region is reduced to the standard brightness. On the other hand, when the light intensity is lower than the standard brightness value (dark region), the pattern analyzer 330 adjusts the standard brightness value. In this case, it is important that the brightness of each region be adjusted to a uniform brightness when viewed from the image of the camera unit 200.

For example, the pattern analyzing unit 330 extracts the saturation region when the saturation region of the light intensity exists in the data in which the pattern and the coordinates are matched, and extracts the saturated region from the coordinates of the image of the camera unit 200 The brightness of the coordinates of the beam projecting unit 100 corresponding to the saturation region is lowered to a previously stored standard brightness value.

On the other hand, when the pattern intensity is lower than the previously stored standard brightness value, the pattern analyzer 330 determines that the brightness of the coordinates of the image of the camera unit 200 is lower than the previously stored standard brightness value The brightness of the coordinates of the beam projecting unit 100 corresponding to the low region is increased to the previously stored standard brightness value.

At this time, if the camera brightness is higher than a certain threshold value, the light intensity of the beam project coordinates corresponding to the camera corresponding point can be lightly examined up to the threshold value. In addition, the weight of the Gaussian form can be subtracted from the light intensity by considering the beam project.

The 3D rendering unit 340 restores the brightness-adjusted image to a 3D image. More specifically, an image in which the brightness of each region is uniformly adjusted is uniform in brightness of the image acquired by the camera unit 200, and the image is reconstructed into a three-dimensional image.

Referring to FIG. 3, FIG. 3 is a front and a rear view of a three-dimensional image reconstructed by a pattern light source illuminating system for a local region of the three-dimensional shape measuring structural light according to the present invention.

In the case of the general pattern, since the global brightness is controlled according to the aperture, when the image is measured from the camera viewpoint, the thickness of the pattern is different according to the position as shown in the camera image of the general pattern. As shown in the binarization result of the general pattern, when the binarization process is performed, a pattern is missed in a part having a high brightness, and this occurs as an error in three-dimensional reconstruction.

However, according to the pattern light source illuminating system for the three-dimensional shape measuring structural light of the present invention, when the brightness is adaptively controlled according to the local coordinates at the position viewed by the camera, as shown in the camera image of the adaptive pattern, A precise pattern can be obtained from a camera viewpoint even in a measurement object in which a glare (diffuse reflection) phenomenon is strongly caused, such as a metal. In addition, when the data is binarized, the pattern can be accurately measured without interruption as in the case of the binary result of the adaptive pattern.

4 is a flowchart of a method of irradiating a pattern light source for a local region of a three-dimensional shape measuring structural light according to the present invention.

The method for irradiating the pattern light source for the three-dimensional shape measurement structural light according to the present invention may further comprise the steps of irradiating white light (S100), imaging (S200), modeling (S300), pattern irradiation (S400) S500, a light intensity adjusting step S600, and a three-dimensional restoring step S700.

The white light irradiation step (S100) irradiates the measurement object (10) with white light using the beam project part (100).

 The image capturing step S200 captures the measurement object 10 to which the white light is irradiated using the camera unit 200. [

The modeling step S300 models a brightness distribution diagram of the image obtained by the camera unit 200. FIG. When the image obtained from the camera section is uniformly uniform in brightness, the adaptive pattern is examined. On the contrary, if the brightness is not uniform, the model is re-modeled.

The pattern irradiation step S400 irradiates the light source of the pattern shape with the measurement object 10 using the beam project part 100. [

The pattern irradiating step S400 may include generating coordinates on the image of the measurement object 10 acquired by the camera unit 200 and matching the pattern irradiated through the beam project unit 100 with the coordinates .

In the light intensity extracting step S500, the image of the measurement object 10 irradiated with the light source of the pattern shape is photographed, and the light intensity of each pattern region is extracted from the image. That is, the light intensity extracting step (S500) extracts a region higher or lower than a standard brightness value for each pattern region in the image acquired through the camera unit.

The light intensity adjusting step S600 adjusts the brightness of the light intensity of each pattern extracted in the light intensity extracting step S400. More specifically, in the light intensity control step S600, when the light intensity of each region extracted in the light intensity extraction step S500 exists in a region corresponding to the saturation region, The brightness of the saturation region with respect to the coordinates of the beam project unit 100 corresponding to the saturation region is reduced to a previously stored standard brightness value.

In the light intensity control step S500, when the light intensity among the light intensities of the respective regions extracted in the light intensity extraction step S500 is less than the previously stored standard brightness value, The brightness of the coordinates of the beam projecting unit 100 corresponding to the pre-stored standard brightness value is increased to the pre-stored standard brightness value.

In the three-dimensional reconstruction step (S700), the image obtained by adjusting the light intensity of each pattern region is reconstructed in three dimensions.

 More specifically, in the case of a general pattern, global brightness is controlled according to a diaphragm. Therefore, when an image is measured from a camera viewpoint, the thickness of the pattern varies depending on the position as seen from a camera image of a general pattern. As shown in the binarization result of the general pattern, when the binarization process is performed, a pattern is missed in a part having a high brightness, and this occurs as an error in three-dimensional reconstruction.

However, in the three-dimensional reconstruction step (S700), as shown in the camera image of the adaptive pattern, if the brightness is adaptively controlled according to the local coordinates at the position viewed by the camera, the glare (diffuse reflection) Accurate measurement of the object to be measured can be obtained from the viewpoint of the camera. In addition, when the data is binarized, the pattern can be accurately measured without interruption as in the case of the binary result of the adaptive pattern.

It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

10: object to be measured
100: beam project part
200: camera unit
300:
310: pattern generator
320: Coordinate system analysis unit
330: pattern control unit
340: pattern analysis section
350: 3D rendering unit
S100: white light irradiation step
S200:
S300: Modeling step
S400: pattern irradiation step
S500: Light intensity extraction step
S600: Light intensity control step
S700: 3D restoration step

Claims (8)

One beam project part (100) for irradiating a light source with the measurement object (10);
A camera unit (200) for capturing an image of the measurement object (10) irradiated with the light source; And
And a control unit (300) for controlling the beam project unit (100) to adjust brightness according to a local position of the measurement object (10)
The control unit 300
A pattern generating unit 310 for generating a pattern in a light source of the beam projecting unit 100;
A coordinate system analyzer 320 for generating coordinates on the image of the camera unit 200;
A pattern control unit 330 for matching the pattern of the beam project unit 100 with the coordinates of the camera unit 200; And
When the saturation region is present in the data in which the pattern and the coordinates are matched, the saturation region is extracted and the light intensity of the beam project unit 100 is adjusted, If the brightness of the coordinates of the beam projecting unit 100 corresponding to the saturation region is lowered to a previously stored standard brightness value or an area where the light intensity is lower than the standard brightness value stored in the data in which the pattern and coordinates match is present , And adjusts the light intensity of the beam project unit 100 to adjust the coordinates of the image of the camera unit 200 to the coordinates of the beam project unit 100 corresponding to a region having a brightness lower than the previously stored standard brightness value A pattern analysis unit 340 for increasing the brightness of the image to a previously stored standard brightness value;
Wherein the pattern light source irradiates the pattern light source for each local region of the structured light for three-dimensional shape measurement.
The method according to claim 1,
The control unit 300
A three-dimensional rendering unit 350 for reconstructing the brightness-adjusted image into a three-dimensional image;
Wherein the pattern light source irradiates the pattern light source for each local region of the structured light for three-dimensional shape measurement.
delete delete A white light irradiation step (S100) of irradiating white light to the measurement object (10) using the beam project part (100);
An image capturing step (S200) of capturing the measurement object (10) irradiated with the white light using the camera unit (200);
A brightness distribution modeling step S300 for modeling the brightness distribution of the image obtained by the camera unit 200;
A pattern irradiating step (S400) of irradiating a light source of a pattern shape to the measurement object (10) using the beam project part (100);
A light intensity extracting step (S500) of photographing an image of the measurement object (10) irradiated with the pattern-shaped light source and extracting light intensity of each pattern region in the image;
When the light intensity of each region extracted in the light intensity extracting step (S500) exists in a region corresponding to the saturation region, the light intensity of the beam projecting unit 100 is adjusted, The brightness of the coordinates of the saturation region corresponding to the coordinates of the beam project unit 100 may be lowered to a previously stored standard brightness value or the light intensity of each region extracted in the light intensity extraction step S500 may be If there is an area below the pre-stored standard brightness value, the light intensity of the beam project unit 100 is adjusted to adjust the light intensity of the beam project corresponding to the pre-stored standard brightness value in the image coordinates of the camera unit 200 A light intensity adjusting step (S600) of increasing the brightness of the coordinates of the unit (100) to a previously stored standard brightness value; And
A three-dimensional reconstruction step (S700) for reconstructing the image obtained by adjusting the light intensities of the respective regions of each pattern to three dimensions after acquiring the image;
Wherein the pattern light source irradiates the pattern light source for local region of the three-dimensional shape measuring structural light.
6. The method of claim 5,
The pattern irradiation step (S400)
Dimensional coordinates of the object to be measured 10 obtained by the camera unit 200 and matches the coordinates of the pattern to be irradiated through the beam projecting unit 100. [ A method of irradiating a pattern light source by local region of structured light.
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