JP2021182259A - Detection marker - Google Patents

Abstract

To provide a detection marker that is not likely to cause a reduction in recognition precision even if used at the outdoor.SOLUTION: A detection marker 10 that is installed at predetermined coordinates on a real space so as to display a composite real space formed by combining an actual object in the real space with a virtual object on a display. This marker includes a first identification element 11 and a second identification element 12 which have different contrasts, and either one of the first identification element 11 or the second identification element 12 can emit light.SELECTED DRAWING: Figure 1

Description

The present invention relates to a detection marker used by installing it at a predetermined coordinate in the real space in order to display a mixed real space formed by combining a real object and a virtual object in the real space on a display, particularly outdoors. The present invention relates to a detection marker suitable for use in a large space.

In recent years, technological advances called AR (Augmented Reality) and MR (Mixed Reality) have been remarkable. This is a common technology in that both the real world and the virtual world are fused.
For example, Patent Document 1 describes the arrangement of each feature point set obtained by photographing and recognizing a plurality of feature point sets arranged in a real space as a mixed reality system targeting a relatively wide space such as outdoors. A technique for generating an image of a virtual object superimposed on a real space on a display based on position information and relative position information with a photographing device is disclosed.

Japanese Patent No. 6640294

However, in the case of the invention described in Patent Document 1, when a marker consisting of a combination of white and black squares used as a feature point set is used outdoors, the brightness is remarkable due to reflection of sunlight or changes in weather. The recognition accuracy of the marker may decrease due to the decrease, etc., and it was necessary to take measures such as providing an antireflection coating.

Therefore, an object of the present invention is to provide a detection marker that is unlikely to cause a decrease in recognition accuracy even when used outdoors.

The first invention of the present application, which has been made to solve the above-mentioned problems, is installed at predetermined coordinates in the real space in order to display a mixed real space formed by combining a real object and a virtual object in the real space on a display. It is a detection marker, which is composed of a first identification element and a second identification element having different contrasts, and one of the first identification element and the second identification element is configured to be capable of emitting light. It is characterized by that.
Further, in the second invention of the present application, in the first invention, the first identification element is colored with the first color, and the second identification element emits light with the second color. It is characterized by being composed of.
Further, the third invention of the present application is characterized in that, in the second invention, the emission color of the second identification element can be set to an arbitrary color.
Further, the fourth invention of the present application is characterized in that, in the second invention or the third invention, the second identification element is detachably configured with respect to the background material functioning as the first identification element. And.
Further, the fifth invention of the present application is characterized in that, in at least one of the second to fourth inventions, the light emission of the light emitting body is individually controllable.
Further, the sixth invention of the present application is characterized in that, in at least one of the second to fifth inventions, the light emitting body functions as the first discriminating element when the light is not emitted.
Further, the seventh invention of the present application is characterized in that, in at least one of the second to fifth inventions, the light emitting body functions as the second discriminating element even when the light is not emitted. ..

According to the present invention, at least one of the effects described below is exhibited.
(1) By configuring either the first identification element or the second identification element having different contrasts so that light can be emitted, the brightness is reduced due to the reflection of light on the marker or the insufficient amount of light, such as outdoors. The marker detection accuracy can be maintained even in the field.
(2) By configuring the emission color of the second identification element to be set to any color, it is possible to use an emission color that does not adversely affect the detection accuracy according to the site conditions.
(3) By detachably configuring the second identification element with respect to the background material that functions as the first identification element, it is possible to create different detection layouts with one detection marker.
(4) By configuring the light emission of a plurality of light emitters to be individually controllable, it is possible to create different detection layouts with one detection marker.
(5) Since the light emitting body functions as the first identification element when the light emitting body does not emit light, it is possible to create different detection layouts with one detection marker by controlling the light emission of the light emitting body.
(6) Since the light emitting body functions as a second identification element even when the light emitting body does not emit light, it can be diverted to a site where light emission is not required, such as indoor use.

The schematic diagram of the detection marker which concerns on Example 1. FIG. The schematic diagram of the detection marker which concerns on Example 2. The schematic diagram of the detection marker which concerns on Example 3. FIG. The schematic diagram of the detection marker which concerns on Example 4. FIG. The schematic diagram of the mixed reality space provision system which concerns on Example 5. Schematic diagram showing a generated image of a mixed reality space.

Hereinafter, examples of the present invention will be described with reference to the drawings.

<1> Overall configuration (Fig. 1)
FIG. 1 shows a schematic diagram of the detection marker 10 according to the first embodiment.
A plurality of detection markers 10 according to the present invention are installed at predetermined coordinates in the real space in order to display a mixed real space formed by combining a real object and a virtual object in the real space on a display. This is for calculating the shooting position from the captured image obtained by capturing these detection markers 10.
The mixed reality space may be either a still image or a moving image.
The detection marker 10 according to the present invention is composed of a first identification element 11 and a second identification element 12 having different contrasts, and a surface provided with the first identification element 11 and the second identification element 12 is a detection surface. The detection surface is arranged and used so as to substantially face the photographing device.
On the detection surface, the arrangement of the second identification element 12 is appropriately set for the first identification element 11, so that the top, bottom, left, right, rotation angle, and the like of the mark can be identified.
For these arrangement modes, known layouts used in AR markers can be adopted.

Then, in the present invention, any one of the first identification element 11 and the second identification element 12 constituting the detection surface is configured to be capable of emitting light.
As the emission color by any one of the first identification element 11 and the second identification element 12, any color can be selected so that the contrast ratio with the coloring of the other identification element becomes large. ..
In FIG. 1, a background material colored in black is used as the first identification element 11, and a light emitting body 121 that emits white light is used as the second identification element 12.
The details of each element will be described below.

<2> First Discrimination Element The first identification element 11 is an element for enabling the detection pattern to be read by the detection surface in combination with the second identification element 12 having a different contrast.
In this embodiment, the first identification element 11 uses a plate material colored in black, and functions as a background material for detecting the arrangement of the second identification element 12, which will be described later.

<3> Second identification element The second identification element 12 is an element for enabling the detection pattern to be read by the detection surface in combination with the first identification element 11 having a different contrast.
In this embodiment, the second identification element 12 uses a light emitting body 121 that emits white light.
It is desirable that the light emitter 121 has a high directivity toward the front of the detection marker 10.
In this embodiment, the light emitting body 121 is composed of a single or a plurality of LEDs, and is freely lit by a control circuit (not shown) provided on the back surface of the plate material constituting the first identification element 11. ..
By causing the second identification element 12 to emit light, the contrast ratio with the first identification element 11 can be kept large even when the detection surface is irradiated with sunlight, and the detection surface can be maintained. It is possible to suppress the deterioration of the detection accuracy when the binarization process is performed.
It is desirable that the light emitter 121 and the control circuit be waterproofed or the like so as to have weather resistance.

[Installation of eaves] (Fig. 2)
The detection marker 10 according to the present invention may be provided with an eaves portion 13 separately.
In the detection marker 10 shown in FIG. 2, the eaves portion 13 is provided on the upper surface of the plate material constituting the first identification element 11.
With the eaves 13, it is possible to suppress the irradiation of sunlight on the detection surface, and it is possible to further suppress the deterioration of the detection accuracy when the detection surface is binarized.
In the present invention, the position where the eaves portion 13 is provided is not particularly limited, and may be provided so as to project forward from the entire circumference of the detection surface.
Further, by making the eaves portion 13 detachable as appropriate, it may be configured so that it can be attached to any place according to the position of the sun.

[Detachment mechanism of each identification element] (Fig. 3)
In the detection marker 10 according to the present invention, the first identification element 11 and / or the second identification element 12 may be detachably configured.
In the detection marker 10 shown in FIG. 3, the second identification element 12 is detachably configured with respect to the first identification element 11.
A known means can be used as the attachment / detachment mechanism.
In FIG. 3A, the female portion 141 of the surface fastener 14 is attached to a predetermined position of the background material to be the first identification element 11, and the male portion 142 of the surface fastener 14 is attached to the back surface of the second identification element 12. Is attached so that the second identification element 12 can be attached and detached at a predetermined position.
Further, in FIG. 3B, the female portion 141 of the hook-and-loop fastener 14 is provided over the entire surface of the background material serving as the first identification element 11, and the second identification element 12 can be attached to an arbitrary position. It is configured as follows.
According to this configuration, it is possible to easily switch between a plurality of detection patterns having different arrangement locations and arrangement numbers of the second identification element 12.

If the female portion 141 itself of the surface fastener 14 to be attached to the background material to be the first identification element 11 shown in FIG. 3A is configured to have the same color as the second identification element 12, it is indoors. It is also possible to function as a detection marker 10 that can be used in the field without using the second identification element 12 using the light emitter 121 such as.

[Use when not emitting light] (Fig. 4)
The detection marker 10 according to the present invention may be configured to function as the first identification element 11 when the second identification element 12, which is the light emitting body 121, is in the non-emission state.
The detection marker 10 shown in FIG. 4 shows a configuration in which light emitters 121 colored with the ground color functioning as the first identification element are arranged vertically and horizontally on the entire surface of the marker.
Each light emitting body 121 is configured so that light emission can be individually controlled.
When the light emitting body 121 is in the non-light emitting state, it is recognized as the first identification element 11 by the ground color of the light emitting body 121, and when the light emitting body 121 is in the light emitting state, it is recognized as the second identification element 12 by the light emitting color. By recognizing, the detection marker 10 set to an arbitrary detection pattern can be obtained by individual control of each light emitting body 121.

Next, a mixed reality space providing system using the detection marker 10 according to the present invention will be described.

<1> Overall configuration (Fig. 5)
In this example, a mixed reality space providing system is configured by using three detection markers 10, a photographing unit 20, a posture detecting unit 30, a calculation unit 40, and a display unit 50.
The photographing unit 20, the posture detection unit 30, the calculation unit 40, and the display unit 50 may be integrated into one device (smartphone, tablet terminal, head-mounted display, etc.), or may be incorporated into another device as appropriate.
In this embodiment, the photographing unit 20 is configured by a digital camera, the attitude detection unit 30 is configured by an angle sensor fixed to the digital camera, the arithmetic unit 40 is configured by a notebook PC, and the display is configured by an external monitor. There is.
The details of each part will be described below.

<2> Detection marker The detection marker 10 is an object to be photographed by the photographing unit 20 described in Examples 1 to 4 and the like, and the coordinates of the photographing unit 20 are obtained based on the photographed image on which the detection marker 10 is reflected. Is an element of.
The detection markers 10 are installed at at least three places, and three-dimensional coordinates are obtained for each detection marker 10.
Then, by including the detection markers 10 at these three locations in the image captured by the photographing unit 20, the position and size of each detection marker 10 and the coordinate information predetermined for each detection marker 10 are used. It is possible to obtain three-dimensional information of the captured image.

<3> Imaging unit The imaging unit 20 is an element for photographing the detection marker 10 and the surrounding real space.
The photographing unit 20 has a function of acquiring a photographed image in a state where at least three detection markers 10 are contained in the angle of view and transmitting the photographed image to the calculation unit 40.
A general digital camera can be used for the photographing unit 20, but if it is a twin-lens stereoscopic camera attached to the front of the HMD, it is possible to calculate the depth position of the marker, and the position calculation accuracy can be improved. ..

<4> Posture detection unit The posture detection unit 30 is an element for detecting the posture (angle) of the photographing unit 20.
The attitude detection unit 30 is obtained from the angular acceleration (x _g , y _g , z _g ), angular velocity (x _r , y _r , z _r ), and geomagnetic information (x _t , y _t , z _t ) of the photographing unit 20. It has a function of acquiring the posture (angle) (posture information) of the photographing unit 20 and transmitting it to the calculation unit 40.
In this embodiment, the posture detection unit 30 is composed of an angle sensor.

<5> Calculation unit The calculation unit 40 is an element for generating a mixed reality space based on the captured image from the photographing unit 20 and the posture information from the posture detecting unit 30.
The calculation unit 40 analyzes images of three or more detection markers in the captured image, and uses the coordinate information (x _1-3 , y _1-3 , z _1-3 ) of each detection marker stored in advance as a reference point. as a function for obtaining the three-dimensional coordinates of the imaging unit 20 using known surveying methods _{(x 0, y 0, z} 0), with the three-dimensional coordinates _{(x 0, y 0, z} 0), the position detection Based on the attitude information (x _r , y _r , z _r ) from the unit 30, it has a function of generating a composite real space formed by combining a virtual object with a real object in the real space in the captured image.
In this embodiment, the arithmetic unit 40 is composed of an information processing terminal such as a notebook PC.

<6> Display unit The display unit 50 is an element for displaying a mixed reality space on a screen.
The display unit 50 has a function of displaying information on the mixed reality image sent from the calculation unit 40 on the screen.
In this embodiment, the display unit 50 is configured by an external display capable of inputting video information from an information processing terminal.

<7> Usage image (Fig. 6)
The generated image of the mixed reality space will be described with reference to FIG.
First, using the binarized image of the captured image A shown in FIG. 6A, three detection markers 10 are specified, and the positions and sizes of the detection patterns on each detection marker 10 and each detection are performed. The three-dimensional coordinates (x ₀ , y ₀ , z ₀ ) of the photographing unit 20 are obtained from the three-dimensional coordinates (x _1-3 , y _1-3 , z _{1-3) of the marker 10.}
Based on the three-dimensional coordinates (x ₀ , y ₀ , z ₀ ) of the photographing unit 20, the attitude information obtained from the attitude detection marker 10, and the coordinate information of the virtual object B saved in advance, the photographed image A is displayed. By combining the virtual object B with the real object A1 in the real space that appears, the mixed reality space C shown in FIG. 6B can be generated.

[Detection marker selection function by the calculation unit] (not shown)
When the captured image contains three or more detection markers 10, the calculation unit 40 may calculate the three-dimensional coordinates of the photographing unit 20 using all the detection markers 10, or three as appropriate. The calculation may be performed by extracting the marker 10 for detecting the location.
For example, a method for extracting the detection marker 10 can be appropriately designed.
For example, a method may be considered in which the captured image is divided into three in the horizontal direction and one of the detection markers 10 arranged in each divided area is selected.
In order to improve the coordinate accuracy, the three detection markers 10 are arranged so that the line segment connecting the detection markers 10 is long and the depth is generated in the front-back direction at the angle of view of the captured image. Therefore, it is desirable to set the detection algorithm so that this arrangement mode is prioritized.

10 Detection marker 11 First identification element 12 Second identification element 121 Eaves 13 Eaves 14 Hook-and-loop fastener 141 Female part 142 Male part 20 Photographing unit 30 Posture detection unit 40 Calculation unit 50 Display unit 60 Photographed image 61 Real object 70 virtual object 80 mixed reality space

Claims (7)

It is a detection marker installed at predetermined coordinates in the real space in order to display the mixed real space formed by combining the real object and the virtual object in the real space on the display.
It consists of a first discriminating element and a second discriminating element having different contrasts.
One of the first identification element and the second identification element is configured to be capable of emitting light.
Detection marker. The first identification element is colored with the first color.
The second identification element comprises a light emitter that emits light in a second color.
The detection marker according to claim 1. It is characterized in that the emission color of the second identification element is configured to be configurable to any color.
The detection marker according to claim 2. The second identification element is detachably configured with respect to the background material that functions as the first identification element.
The detection marker according to claim 2 or 3. It is characterized in that the light emission of the light emitting body is individually controllable.
The detection marker according to any one of claims 2 to 4. The illuminant is characterized in that it functions as the first identification element when it does not emit light.
The detection marker according to any one of claims 2 to 5. The illuminant is characterized in that it functions as the second identification element even when it does not emit light.
The detection marker according to any one of claims 2 to 5.

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