KR101691880B1 - Interactive System Having Auto Calibration Function And Auto Calibration Method of Interactive System - Google Patents

Abstract

The present invention provides an interactive system and a calibration method for an interactive system. The interactive system includes: a screen on which a picture is projected; a computer for generating image information of a first resolution; a projector for receiving the image information from the computer and projecting a picture on the screen; a writing means for emitting a signal while moving on the screen; a camera unit for capturing an image of the screen to recognize screen coordinates indicating a position of the writing means on the screen; and a controller for switching the screen coordinates to image coordinates indicating a position on the image information corresponding to the screen coordinates, wherein the computer receives and stores the image coordinates from the controller or displays the image coordinates in an image format, and performs a predetermined command according to the signal. The projector projects, onto the screen, a calibration image including at least two types of patterns having the same shape but different sizes. The camera unit captures the calibration image and generates a calibration video. The controller compares positions of the patterns each included in the calibration image and the calibration video, and performs calibration such that the screen coordinates correspond to the image coordinates. According to the interactive system and the calibration method for the interactive system, a pattern recognition rate in a calibration image is increased, thereby enabling more accurate calibration.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic calibration method for an interactive system and an interactive system having an automatic calibration function,

The present invention relates to an interactive system having an automatic calibration function and an automatic calibration method using the same. More particularly, the present invention relates to an interactive system for increasing the recognition rate of a pattern included in a calibration image, And an automatic calibration method.

1 is a reference diagram for explaining a conventional interactive system. Referring to FIG. 1, an image of image information generated in the computer 10 is projected onto the screen 30 through the projector 20.

Then, when the authoring means 50 moves on the screen 30, the camera 40 tracks the position in real time, converts it into coordinate data, and transmits it to the computer 10. At this time, the computer 10 synthesizes the original image information with the coordinate data of the authoring means.

When the image information obtained by synthesizing the coordinate data of the writing means is projected onto the screen 30 through the projector 20, the position of the writing means 50 and the projection position on the screen must coincide.

The process for matching them is referred to as calibration. In the past, manual calibration that requires the user's operation has been mainly applied.

2 is a diagram for explaining a manual calibration process. 2, the image information generated in the computer 10 is projected onto the screen 30 through the projector 20, and when the calibration process is started, as shown in FIG. 2 (a) A specific image appears at a specific position (A). At this time, when the user touches the specific position A, the position of the specific image moves to (B) as shown in (b) of FIG. 2 and again when the user touches the position of (B) The position is shifted to the sequentially set values of (C) to (I), and the user sequentially touches the position of the specific image sequentially displayed, and the computer 10 recognizes the position of the specific image sequentially.

On the other hand, in the case of the above-described manual calibration, the user has to repeatedly perform the above-described operation, which is problematic in that it is rather cumbersome.

In order to solve such a problem, recently, a calibration image in which a specific pattern is repeated is projected onto the screen 30 through the projector 20, and a calibration image taken through the camera 40 is obtained, And an automatic calibration method for completing a calibration process by comparing the position of the specific pattern in a calibration image photographed through a camera is used.

However, in the case of such an automatic calibration method, as the position of the repeated patterns deviates from the photographing center of the camera 40, the distortion of the pattern shape in the calibration image may become worse, .

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-described problems, and it is an object of the present invention to provide a projection apparatus and a projection apparatus which project a calibration image including at least two types of patterns, An interactive system in which calibration is performed, and a calibration method using the same.

An interactive system according to the present invention includes: a screen on which a screen is projected; A computer for generating image information of a first resolution; A projector which receives image information from the computer and projects a screen on the screen; A writing means for moving on the screen and emitting a signal; A camera unit for photographing the screen and recognizing screen coordinates indicating a position on the screen of the authoring means; And a control unit for converting the image coordinates into image coordinates representing a position on the image information corresponding to the screen coordinates, wherein the computer receives the image coordinates from the control unit or stores the image coordinates in an image form, Wherein the projector projects a calibration image including at least two types of patterns having the same shape and size in different sizes on the screen, and the camera unit is configured to capture the calibration image The control unit compares positions of the patterns included in the calibration image and the calibration image to perform calibration so that the screen coordinates and the image coordinates correspond to each other.

In the interactive system according to the present invention, the calibration image includes two patterns having different sizes, and a pattern having a relatively small size may be located at a central portion.

In the interactive system according to the present invention, the size of the pattern may be smaller as the straight line length from the position on the screen on which the pattern is projected to the camera unit is shorter.

In the interactive system according to the present invention, the control unit may recognize an area corresponding to the calibration image in the calibration image as a writing area.

In the interactive system according to the present invention, the control unit recognizes the area other than the writing area as the menu area in the calibration image, indicates that the screen coordinates of the writing area are in the menu area, Upon signaling, the computer can cause the computer to perform a predetermined operation.

In the interactive system according to the present invention, in the calibration image, the brightness of the pattern may be lower than the brightness of the background.

In the interactive system according to the present invention, the control unit may store coordinate conversion information in which the screen coordinates are converted into the image coordinates.

In the interactive system according to the present invention, when the resolution of the image information generated in the computer is changed to the second resolution, the control unit converts the stored coordinate conversion information into a scaling operation according to the difference between the first resolution and the second resolution So as to be suitable for the second resolution.

A method of calibrating an interactive system according to the present invention includes: a screen on which a screen is projected; A computer for generating image information of a first resolution; A projector which receives image information from the computer and projects a screen on the screen; A writing means for moving on the screen and emitting a signal; A camera unit for photographing the screen and recognizing screen coordinates indicating a position on the screen of the authoring means; And a control unit for switching to image coordinates representing a position on the image information corresponding to the screen coordinates, wherein the computer receives and stores the image coordinates from the control unit or expresses the image coordinates in an image form, An image projecting step of projecting a calibration image including at least two types of patterns, which are the same in shape and different in size, onto the screen; An image photographing step of photographing the calibration image to generate a calibration image; And a calibration step of correlating screen coordinates and image coordinates by comparing positions of the patterns included in the calibration image and the calibration image, respectively.

In the method of calibrating an interactive system according to the present invention, the calibration image may include two patterns having different sizes, and a pattern having a relatively small size may be located at a central portion.

In the method of calibrating an interactive system according to the present invention, the size of the pattern may be smaller as the straight line length from the position on the screen on which the pattern is projected to the camera unit is shorter.

The method of calibrating an interactive system according to the present invention may further include storing coordinate transformation information for associating the screen coordinates and the image coordinates.

A calibration method of an interactive system according to the present invention includes: a resolution change checking step of checking whether a resolution is changed; And a coordinate conversion information scaling step of, when there is a change in resolution, changing the coordinate conversion information so as to match the resolution changed by the scaling operation according to the resolution difference.

According to the interactive system and the calibration method using the same, a calibration image including at least two types of patterns having the same shape and different sizes is projected on a screen, and the pattern recognition rate in the captured calibration image is calculated So that a more accurate calibration can be performed.

1 is a reference diagram for explaining a conventional interactive system;
2 is a diagram for explaining a manual calibration process;
3 is a conceptual diagram of an interactive system according to an embodiment of the present invention.
4 is a reference view showing a state in which a calibration image is projected on the screen 110. Fig.
5 is a reference view of a calibration image generated by photographing a calibration image projected on a screen of a camera unit.
FIG. 6 is an exemplary view showing an example of a menu region and a writing region of a screen; FIG.
7 is a flowchart illustrating a calibration method according to an embodiment of the present invention.

Hereinafter, specific embodiments of the present invention will be described in detail with reference to the drawings. It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the inventive concept. Other embodiments falling within the scope of the inventive concept may be easily suggested, but are also included within the scope of the invention.

In the following description, the same reference numerals are used to designate the same components in the same reference numerals in the drawings.

3 is a conceptual diagram of an interactive system 100 according to an embodiment of the present invention.

3, an interactive system 100 according to an embodiment of the present invention includes a screen 110 on which a screen is projected, a computer 120 that generates image information, image information from the computer 120 A projector 130 for receiving a screen and projecting a screen on the screen, a puncher means 140 for moving a signal on the screen 110, a screen 110 for capturing the position of the puncher means 140 And a controller 160 for receiving and processing information from the camera unit 150 and the computer 120.

The screen 110 may allow the user to visually recognize the image information projected through the projector 130. In other words, the screen 110 may allow a user to view an image projected through the projector 130. For this, the screen 110 may be provided in a white plane form. In addition, the screen 110 may be provided in a rectangular planar shape.

The computer 120 may be a general computing device having a computing and storing function, and the computer 120 may store and execute a programming program. In addition, the computer 120 may generate image information of a predetermined resolution, and may project the image information on the screen 110 through a projector 130, which will be described later. In addition, the computer 120 may receive and store the position information of the writing means 140, which will be described later, in real time, or may represent the image information in an image form. The computer 120 may synthesize the position information with the image information, And projected onto the screen 110. Meanwhile, the computer 120 may change the resolution of the image information to be projected. In other words, the computer 120 may change the resolution of the image information projected through the projector 130, which will be described later, from the first resolution to the second resolution according to need or at the user's choice. On the other hand, the computer 120 can receive a signal from the writing means 140, which will be described later, and perform a predetermined command. In addition, according to a signal issued by the writing means 140 described later, the color representing the position information of the writing means 140 in an image form can be expressed differently. In other words, depending on the frequency of the signal generated by the writing means 140, the color may be expressed in a different color or the color may be changed in a predetermined order each time a specific signal is issued. Also, the position information of the planner means 140 can be imaged only when the signal issued by the planner means 140 corresponds to a specific frequency.

The projector 130 receives image information from the computer 120 and can project the image information on the screen 110. [ In other words, the projector 130 may project image information on the screen 110 so that the user can recognize the image information visually. Further, the projector 130 may project the calibration image CI onto the screen 110. [

4 is a reference view showing a state in which the calibration image CI is projected onto the screen 110. FIG. Referring to FIG. 4, the calibration image CI may include at least two types of patterns P1 and P2 having the same shape and different sizes. That is, the first pattern P1 may be larger than the second pattern P2. At this time, a second pattern P2 having a relatively small size is arranged at a central portion and a first pattern P1 having a relatively large size is arranged at an outer perimeter of the patterns P1 and P2 . The sizes of the patterns P1 and P2 may be smaller as the straight line length from the position on the screen 110 onto which the patterns P1 and P2 are projected to the camera unit 150 described later is shorter. 3 and 4, the straight line length from the position on the screen 110 onto which the patterns P1 and P2 are projected is longer than the straight line length from the center portion of the screen 110 to the camera portion 150. In other words, And becomes longer as the distance from the upper center of the screen 110 increases. Accordingly, the first pattern P1 may be disposed along both left and right ends of the screen 110, and the second pattern P2 may be disposed at the upper center portion.

5 is a reference view of a calibration image CV generated by capturing a screen on which the calibration image CI is projected on the screen 110 by the camera unit 150 described later. The patterns P1 and P2 reflected on the calibration image CV may be distorted as the straight line length from the camera unit 150 to the position on the screen 110 onto which the patterns P1 and P2 are projected increases, Accordingly, the recognition rate of the patterns P1 and P2 may be lowered. However, by varying the sizes of the patterns P1 and P2 as described above, it is possible to minimize the distortion in the calibration image CV by increasing the size of the first pattern P1 as shown in FIG. The recognition rate of the patterns P1 and P2 can be increased.

On the other hand, in the calibration image (CI), the brightness of the pattern (P1, P2) may be lower than the brightness of the background. In other words, the colors of the patterns P1 and P2 may be darker than the background color. For example, in the calibration image CI, the patterns P1 and P2 may be black and the background may be white. Accordingly, the degree of recognition of the patterns P1 and P2 can be further increased in the calibration image CV generated by photographing with a camera described later.

The writing means 140 can be moved on the screen 110. In addition, the writing means 140 can generate a signal, and the computer 120 can execute a specific command according to a signal issued by the writing means 140. Also, the authoring means 140 can change the frequency of the signal. Accordingly, the computer 120 can change the color of the image of the position information of the writing means 140 according to the change of the signal generated by the writing means 140.

The camera unit 150 can photograph the screen 110 and recognize the screen coordinates Sx and Sy indicating the position of the writing means 140 on the screen 110. [ In other words, the camera unit 150 can recognize the screen coordinates (Sx, Sy) of the authoring means 140 in real time and transmit it to the control unit 160, which will be described later. In addition, the camera unit 150 may capture the calibration image CI to generate a calibration image CV.

The control unit 160 receives the screen coordinates Sx and Sy from the camera unit 150 and generates image coordinates Vx and Vy indicating the positions on the image information corresponding to the screen coordinates Sx and Sy, . ≪ / RTI >

The control unit 160 compares the calibration image CV received from the camera unit 150 with a calibration image CI projected from the projector 130 and outputs the calibration image CI of the pattern P1, The screen coordinates Sx and Sy and the image coordinates Vx and Vy correspond to each other so that the coordinates Sx and Sy correspond to the image coordinates Vx and Vy of the patterns P1 and P2 can do. Since the size of the patterns P1 and P2 is large as the degree of distortion in the calibration image CV is large, the controller 160 controls the patterns P1 and P2 in the calibration image CV, It is possible to more clearly recognize the position of the light source.

On the other hand, the controller 160 may store the coordinate conversion information in which the screen coordinates Sx, Sy are converted into the image coordinates Vx, Vy. By storing the coordinate conversion information in this way, the control unit 160 projects the calibration image CI when the interactive system 100 according to the embodiment of the present invention is restarted, captures and calibrates the calibration image CI The screen coordinates (Sx, Sy) can be switched to the image coordinates (Vx, Vy) by using the stored coordinate conversion information without repeating the process of performing the process.

In addition, when the resolution of the image information generated by the computer 120 is changed from the first resolution to the second resolution through the stored coordinate conversion information, the controller 160 performs a calibration process It can be avoided. In other words, the controller 160 may change the stored coordinate conversion information to a second resolution by scaling according to the difference between the first resolution and the second resolution. Accordingly, even when the resolution of the image information is changed, the screen coordinates (Sx, Sy) can be immediately converted into the image coordinates (Vx, Vy) without performing the calibration process again.

6 is an exemplary view showing an example of a planer area DA and a menu area MA of the screen 110. FIG. Referring to FIG. 6, the controller 160 may recognize an area corresponding to the calibration image CV in the calibration image CV as a writing area DA. In the calibration image CV, An area other than the area DA can be recognized as the menu area MA. At this time, when the writing unit 140 is located in the writing area DA, the control unit 160 sets the screen coordinates Sx and Sy of the writing unit 140 to image coordinates Vx and Vy, And transmits the image information to the computer 120 in real time so that the real time position of the authoring means 140 can be imaged and synthesized with the image information. In addition, when the writing unit 140 is located in the menu area MA and the writing unit 140 generates a predetermined signal, the computer 120 may perform a specific operation. In other words, the menu area MA can be formed outside the area where the image information generated by the computer 120 is projected, and the puncher unit 140 is positioned at a specific position on the menu area MA, The computer 120 may perform a specific operation. In this way, the menu information for performing the specific operation of the computer can be not included in the image information, so that a more efficient space utilization is possible.

Hereinafter, the calibration method (S100) according to one embodiment of the present invention will be described in detail.

7 is a flowchart illustrating a calibration method (S100) according to an embodiment of the present invention.

7, a calibration method S100 according to an exemplary embodiment of the present invention includes an image projection step S110 for projecting a calibration image CI onto a screen 110, a calibration step S110 for projecting the calibration image CI onto the screen 110, (S120) for capturing an image (CI) to generate a calibration image (CV); comparing the calibration image (CI) with the calibration image (CV) to generate screen coordinates (Sx, Sy) (S140) for storing coordinate transformation information for associating the screen coordinates with the image coordinates, a resolution change check step (S140) for checking whether the resolution of the image information is changed, And a scaling step (S160) of changing the coordinate transformation information to match the changed resolution through the scaling operation when there is a resolution change (S160).

The image projection step S110 may be a step of projecting a calibration image CI including at least two patterns of the ends P1 and P2 of the same shape and of different sizes onto the screen 110. [ At this time, the calibration image CI includes two patterns P1 and P2 having different sizes, and the pattern P2 having a relatively small size may be located at the center. In addition, the calibration image CI is a size of the pattern P1 and P2 as the linear length from the position on the screen 110 onto which the patterns P1 and P2 are projected to the camera unit 150 is short, Can be small.

The image capturing step S120 may be a step of capturing the calibration image CI projected onto the screen 110 through the camera unit 150 to generate a calibration image CV.

The calibration step S130 is a step of comparing the image coordinates Vx and Vy of the patterns P1 and P2 included in the calibration image CI with the screen coordinates of the patterns P1 and P2 captured on the calibration image CV (Sx, Sy) and coordinate transformation information (Vx, Vy) of the image coordinates (Sx, Sy), respectively.

The storing step S140 may be a step of storing the coordinate conversion information generated in the calibration step S130. Accordingly, the stored coordinate conversion information can be utilized without performing calibration every time the interactive system 100 according to an embodiment of the present invention is operated again.

The resolution change check step S150 may be a step of checking whether the resolution of the image information generated by the computer 120 has been changed.

Thereafter, when the resolution of the image information is changed, the coordinate conversion information can be changed in the coordinate conversion information scaling step (S160) so that the coordinate conversion information is adapted to the resolution newly changed by the scaling operation according to the resolution difference.

While the invention has been shown and described with reference to certain embodiments thereof, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention as defined in the appended claims. It will be obvious to those of ordinary skill in the art.

100: Interactive system
110: Screen
120: Computer
130: Projector
140: Writing means
150:
160:
S100: Calibration method
S110: Image projecting step
S120: image shooting step
S130: Calibration step
S140: storage step
S150: Resolution change check step
S160: Scaling step
CI: calibration image
CV: Calibration image
P1, P2: pattern
DA: Writing area
MA: Menu area

Claims (13)

A screen on which a screen is projected;
A computer for generating image information of a first resolution;
A projector which receives image information from the computer and projects a screen on the screen;
A writing means for moving on the screen and emitting a signal;
A camera unit for photographing the screen and recognizing screen coordinates indicating a position on the screen of the authoring means; And
And switching to image coordinates indicating a position on the image information corresponding to the screen coordinates,
The computer system according to claim 1, wherein the computer receives and stores the image coordinates from the control unit, expresses the image coordinates in an image form, and performs a predetermined command according to the signal,
The projector projects a calibration image including at least two types of patterns having the same shape and different sizes to the screen,
The camera unit may photograph the calibration image to generate a calibration image,
Wherein the controller compares positions of the patterns included in the calibration image and the calibration image to perform calibration so that the screen coordinates and the image coordinates correspond to each other,
Wherein the size of the pattern is smaller as the straight line length from the position on the screen on which the pattern is projected to the camera unit is shorter.
The method according to claim 1,
Wherein the calibration image includes two patterns of different sizes and a relatively small pattern is located at a central portion.
delete The method according to claim 1,
Wherein the control unit recognizes an area corresponding to the calibration image as a writing area in the calibration image.
5. The method of claim 4,
Wherein the control unit recognizes an area other than the writing area as a menu area in the calibration image,
Wherein the screen coordinate of the authoring means is in the menu area and the computer makes a predetermined operation when a predetermined signal is issued by the authoring means.
The method according to claim 1,
Wherein the calibration image is such that the brightness of the pattern is lower than the brightness of the background.
The method according to claim 1,
Wherein the control unit stores coordinate conversion information in which the screen coordinates are converted into the image coordinates.
8. The method of claim 7,
When the resolution of the image information generated in the computer is changed to the second resolution,
Wherein the control unit changes the stored coordinate conversion information to conform to the second resolution by a scaling operation according to a difference between the first resolution and the second resolution.
A screen on which a screen is projected;
A computer for generating image information of a first resolution;
A projector which receives image information from the computer and projects a screen on the screen;
A writing means for moving on the screen and emitting a signal;
A camera unit for photographing the screen and recognizing screen coordinates indicating a position on the screen of the authoring means; And
And switching to image coordinates indicating a position on the image information corresponding to the screen coordinates,
The computer is a method of calibrating an interactive system that receives and stores the image coordinates from the control unit, expresses the image coordinates in an image form, and performs a predetermined command according to the signal,
An image projection step of projecting a calibration image including at least two types of patterns having the same shape and different in size onto the screen;
An image photographing step of photographing the calibration image to generate a calibration image; And
And comparing the position of the pattern included in the calibration image and the position of the pattern included in the calibration image with each other to correspond to the screen coordinates and the image coordinates,
Wherein the size of the pattern is smaller as the straight line length from the position on the screen on which the pattern is projected to the camera unit is shorter.
10. The method of claim 9,
Wherein the calibration image includes two patterns of different sizes and a relatively small pattern is located at a central portion.
delete 10. The method of claim 9,
And storing the coordinate conversion information for associating the screen coordinates and the image coordinates.
13. The method of claim 12,
A resolution change check step of checking whether or not there is a change in resolution; And
And a coordinate conversion information scaling step of, when there is a change in the resolution, changing the coordinate conversion information so as to match the resolution changed by the scaling operation according to the resolution difference.

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