KR102454790B1 - System and method of providing replay video of stroke on billiard ball - Google Patents

Abstract

The present invention relates to a method and system for providing a billiard stroke replay image, and an object of the present invention is to extract and provide an image before and after a stroke rotated based on the motion of a billiard ball. In the present invention for achieving this object, in at least one frame included in an image captured by a camera, step a of recognizing a billiard ball, step b of determining the motion and angle of the billiard ball, and before and after the stroke in the image Step c of extracting a first image, step d of generating a second image by rotating the first image based on the angle, extracting a stroke area included in the second image to generate a stroke image, and the and step e of transmitting the first image and the stroke image to a display unit.

Description

Billiard stroke replay video providing method and system {SYSTEM AND METHOD OF PROVIDING REPLAY VIDEO OF STROKE ON BILLIARD BALL}

The present invention relates to a method and system for providing a billiard stroke replay image, and more particularly, to a method and system for providing a billiard stroke replay image that enables precise stroke analysis by providing an image before and after a stroke based on the motion of a billiard ball it's about

The use of video in sports provides various functions, such as broadcast match highlight replay and VAR reading system. It provides a new element to the public by combining video analysis technology as well as simple video playback. For example, it is possible to add fairness to the game by reading in-out through video analysis, provide convenience to customers by combining it with leisure sports, and use it more for educational purposes. Such leisure sports analysis technology can be applied to billiards as well, providing an automatic score count function and a replay function.

The existing billiard replay system lacks a function for stroke analysis. Specifically, as the angle of view of the replay image is set to the entire billiard table, the size of the cue table for analyzing the stroke is relatively small, so it is difficult to accurately analyze the movement of the cue table. It is difficult, and it is difficult to analyze the detailed strokes of the cue group because it provides only general video playback frames (30 to 60 frames), not high-speed frames.

An object of the present invention is to solve the above-mentioned problems, recognize the motion of a billiard ball using a high-speed camera, and extract images before and after a stroke based on this to accurately analyze a stroke.

The present invention for achieving this object is a method for a server to provide a billiard stroke replay image, a step of recognizing a billiard ball in at least one frame included in an image captured by a camera, the movement of the billiard ball, and step b of determining an angle, step c of extracting a first image before and after the stroke from the image, generating a second image by rotating the first image based on the angle, and a stroke area included in the second image and a step d of generating a stroke image by separating them, and a step e of transmitting the first image and the stroke image to a display unit.

In addition, in a system for providing a billiard stroke replay image, the present invention includes a camera that shoots a shooting range including one area of a billiard table, and transmits the captured image to a server, and a billiard ball in at least one frame included in the image. recognizes, determines the motion and angle of the billiard ball, extracts a first image before and after the stroke from the image, rotates the first image based on the angle to generate a second image, and the second image is generated. A server that generates a stroke image by separating a stroke region included in an image, and transmits the first image and the stroke image to a display unit, and a display unit that receives and displays the first image and the stroke image do it with

According to the present invention as described above, the motion of the billiard ball is recognized using a high-speed camera, and based on this, it is possible to accurately analyze the stroke by extracting and providing images before and after the stroke rotated according to the direction in which the ball moves.

1 is a flowchart for explaining a method for providing a billiard stroke replay image according to an embodiment of the present invention;
2 is a flowchart for explaining a method of determining an angle corresponding to the movement of a billiard ball according to an embodiment of the present invention;
3 is a view showing an original frame photographed by a camera according to an embodiment of the present invention;
4 is a view showing a stroke image generated according to an embodiment of the present invention;
5 is a schematic perspective view of a billiard stroke replay image providing system according to an embodiment of the present invention.

The above-described objects, features and advantages will be described below in detail with reference to the accompanying drawings, and accordingly, those skilled in the art to which the present invention pertains will be able to easily implement the technical idea of the present invention. In describing the present invention, if it is determined that a detailed description of a known technology related to the present invention may unnecessarily obscure the gist of the present invention, the detailed description will be omitted.

In the drawings, the same reference numerals are used to refer to the same or similar elements, and all combinations described in the specification and claims may be combined in any manner. And unless otherwise specified, it is to be understood that references to the singular may include one or more, and references to the singular may also include the plural.

The terminology used herein is for the purpose of describing specific exemplary embodiments only and is not intended to be limiting. As used herein, singular expressions may also be intended to include plural meanings unless the sentence clearly indicates otherwise. The term “and/or,” “and/or” includes any and all combinations of the items listed therewith. The terms "comprises", "comprising", "comprising", "comprising", "having", "having" and the like have an implicit meaning, so that these terms refer to their described features, integers, It specifies steps, operations, elements, and/or components and does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. The steps, processes, and acts of the method described herein should not be construed as necessarily performing their performance in such a specific order as discussed or exemplified, unless a specific order of performance is determined. . It should also be understood that additional or alternative steps may be used.

In addition, each component may be implemented as a hardware processor, respectively, the above components may be integrated into one hardware processor, or the above components may be combined with each other and implemented as a plurality of hardware processors.

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

1 is a flowchart illustrating a method for calculating spin of a billiard ball according to an embodiment of the present invention. Referring to FIG. 1 , the camera unit will continuously take pictures within a set shooting range ( S100 ). The camera unit according to an embodiment of the present invention is positioned perpendicular to the billiard table so that the entire billiard table can be photographed, so that the shooting range will be set to the entire area of the billiard table.

The camera unit may transmit the image captured in the shooting range to the server in real time (S109).

The server may recognize whether a billiard ball is present in at least one frame included in the image received from the camera unit (S200). In order to determine the existence of the billiard ball, the server may further apply the color of the billiard ball to a commonly used object recognition method. The server may determine whether a billiard ball is positioned in the frame by recognizing a circular object having white, red, and yellow colors in the frame. The billiard ball referred to in an embodiment of the present invention means being hit by a cue table.

If the server determines that the billiard ball is present in the first frame included in the image, the server may determine the movement of the billiard ball (S300). 2 is a flowchart for explaining a method of determining an angle corresponding to the movement of a billiard ball according to an embodiment of the present invention. When step 300 is specifically described with reference to FIG. The first position of the billiard ball may be identified (S301).

The server may identify the second position of the billiard ball included in the second frame, which is the next frame continuous with the first frame (S302).

The server may recognize the motion of the billiard ball by recognizing the positions of the billiard balls in the first frame and the second frame (S303). The server may determine the motion of the billiard ball by calculating the Euclidean distance between the first position of the billiard ball in the first frame and the second position of the billiard ball in the second frame.

When the server detects the movement of the billiard ball, the server may correct the distortion of the frame (S304).

3 is an original frame photographed from the camera, and it can be seen that distortion has occurred due to a difference in refractive index between the center and the outside of the camera lens, so that the server can correct the distortion. The method of correcting the distortion of the frame by the server according to an embodiment of the present invention may follow the conventional method, such as a method of correcting the distortion rate calculated by checking the spatial positions of three points.

Furthermore, the server may further calculate an angle at which the billiard ball moves by using Equation 1 (S305).

The server will normalize the angle value extracted from at least one frame included in the image (S306). This is to ensure that the angle at which the billiard ball travels always has a constant value. The server may use conventional methods to normalize the angle values.

Returning to the description of FIG. 1 , the server may extract the first image before and after the stroke ( S400 ). The stroke means that the billiard ball is hit by the cue table, and the server considers the point at which the motion of the billiard ball is sensed as the point at which the stroke occurs and extracts the first image before and after the point. In this case, the server may extract as many frames as the number of frames before and after the stroke occurs and set it as the first image.

According to another embodiment of the present invention, the server sets the previous frame at the point of time when the stroke occurs as the preset number of frames, and sets the subsequent frames as frames until the point at which the motion of the billiard ball that recognizes the motion stops, and generates the first image. can also be extracted.

The server may generate a second image by rotating the first image using the angle calculated in step 300 (S500). In the present invention, as the normalization of the angle calculated in step 300 is additionally performed, the angle at which the ball travels is made constant so that the second image can be easily generated.

As the second image generated according to an embodiment of the present invention is generated so that the cue table can be positioned in a vertical direction, the ball hit by the cue table may have a vertical movement corresponding to the movement of the cue table, Unlike the movement of , it may have a movement in a diagonal direction.

The server may generate a stroke image by separating the stroke area from the second image (S600). The server may generate a stroke image by extracting an area of a preset size based on the center point of the billiard ball. Accordingly, the generated stroke image may or may not include a cue table. The preset size of the stroke image is a value changeable by an administrator.

The server may cut out the identified stroke area and set it as a stroke image. The set stroke image is a high-speed frame image of 120 frames per second, enabling precise stroke analysis. An example of the stroke image generated in step 600 is shown in FIG. 4 .

The first image, the second image, and the stroke image according to another embodiment of the present invention may be generated differently according to the number of cameras included in the camera unit. More specifically, when a plurality of cameras are included in the camera unit, the position of the billiard ball extracted from each camera and the angle calculated based thereon are displayed on the 3D coordinate system to be reconstructed in a 3D graphic form.

The server may transmit the first image and the stroke image to the display unit (S609).

The display unit may display the first image and the stroke image received from the server (S700).

Hereinafter, a billiard stroke replay image providing system according to an embodiment of the present invention will be described with reference to FIG. 5 . In the description of the billiard stroke replay image providing system, a detailed embodiment overlapping with the above-described billiard stroke replay image providing method may be omitted. More specifically, the billiard stroke replay image providing system may include a camera unit 10 , a server 20 , and a display unit 30 .

The camera unit 10 may continuously photograph within a set photographing range. The camera unit according to an embodiment of the present invention is positioned perpendicular to the billiard table so that the entire billiard table can be photographed, so that the shooting range will be set to the entire area of the billiard table.

The camera unit 10 may transmit the captured image to the server 20 in real time.

The server 20 may recognize the motion of the billiard ball in the image received from the camera and generate a stroke image based on the motion of the billiard ball. More specifically, the server 20 may include an object recognition unit 21 , a motion recognition unit 22 , a correction unit 23 , an angle calculation unit 24 , an image generation unit 25 , and a communication unit 26 . have.

The object recognition unit 21 may recognize whether a billiard ball is present in at least one frame included in the image received from the camera 10 . The object recognition unit 21 may further apply the color of the billiard ball to a commonly used object recognition method in order to determine whether the billiard ball exists. The object recognition unit 21 may determine whether a billiard ball is positioned in the frame by recognizing a circular object having white, red, and yellow colors in the frame.

If it is determined that the billiard ball is present in the first frame included in the image, the motion recognition unit 22 may recognize the motion of the billiard ball. The motion recognition unit 22 may identify a first position of the billiard ball in the first frame, and identify a second position of the billiard ball included in a second frame that is a next frame continuous with the first frame. The motion recognition unit 22 may determine the motion of the billiard ball by calculating the Euclidean distance between the first position of the billiard ball in the first frame and the second position of the billiard ball in the second frame.

When the motion of the billiard ball is recognized, the correction unit 23 may correct the distortion of the frame. The distortion of the frame is caused by the difference in refractive index between the center and the outer edge of the camera lens, and the correction unit 23 checks the spatial positions of the three points and applies the calculated distortion rate in reverse to correct it. have.

The angle calculator 24 calculates the angle at which the billiard ball moves by using Equation 1, and normalizes the angle value extracted from at least one frame included in the image so that the angle at which the billiard ball moves is always constant.

The image generating unit 25 may generate a first image before and after the stroke, a second image in which the first image is rotated based on the angle calculated by the angle calculating unit 24, and a stroke image obtained by extracting the stroke area from the second image. have.

The image generator 25 may extract the first image before and after the stroke. The image generating unit 25 will extract the first image before and after the point of time when the motion of the billiard ball is sensed as the point at which the stroke occurs. In this case, the image generating unit 25 may extract as many as a preset number of frames from the frames before and after the stroke occurs and set it as the first image.

According to another embodiment of the present invention, the image generating unit 25 sets the previous frame at the point of time the stroke occurs as the preset number of frames, and sets the frame to the frame up to the point at which the motion of the billiard ball that recognizes the motion stops. to extract the first image.

The image generating unit 25 may generate the second image by rotating the first image using the angle calculated by the angle calculating unit 24 . Since the image generating unit 25 always makes the angle value constant by going through the process of normalizing the angle in the angle calculating unit 24, it is possible to easily generate the second image.

The image generator 25 may generate a stroke image by separating a stroke region from the second image. The stroke image is a high-speed image of 120 frames per second, enabling precise stroke analysis.

The communication unit 26 may transmit the first image and the stroke image generated by the image generation unit 25 to the display unit 30 .

The display unit 30 may display the first image and the stroke image received from the server 20 .

Embodiments of the present invention disclosed in the present specification and drawings are merely provided for specific examples in order to easily explain the technical contents of the present invention and help the understanding of the present invention, and are not intended to limit the scope of the present invention. It will be apparent to those of ordinary skill in the art to which the present invention pertains that other modifications based on the technical spirit of the present invention can be implemented in addition to the embodiments disclosed herein.

Claims (6)

A method for a server to provide a billiard stroke replay image,
a step of recognizing a billiard ball in at least one frame included in the image captured by the camera;
b step of determining the motion of the billiard ball and an angle corresponding to the motion;
c step of extracting a first image before and after the stroke from the image;
a d step of generating a second image by rotating the first image based on the angle, and generating a stroke image by separating a stroke region included in the second image;
and step e of transmitting the first image and the stroke image to a display unit.
According to claim 1, wherein the step a,
receiving, from the camera, the image obtained by photographing a shooting range including one area of the billiard table; and
The method for providing a billiard stroke replay image further comprising the step of determining whether the billiard ball is present in the at least one frame.
The method of claim 1, wherein step b comprises:
identifying a first position of the billiard ball in a first frame;
identifying a second position of the billiard ball in a second frame that is a next frame continuous with the first frame; and
and determining the movement using the first and second positions.
4. The method of claim 3,
calculating the angle corresponding to the movement of the billiard ball using the first and second positions; and
Billiard stroke replay image providing method, characterized in that it further comprises the step of normalizing the angle calculated in the at least one frame.
According to claim 1, wherein step c,
Extracting the first image from frames before and after the point in time when the motion of the billiard ball is sensed,
A method for providing a billiard stroke replay image, characterized in that the frame is extracted before and after a preset number of frames.
In the system for providing a billiard stroke replay image,
a camera for photographing a shooting range including one area of the billiard table and transmitting the captured image to a server;
Recognizing a billiard ball in at least one frame included in the image, determining the movement of the billiard ball and an angle corresponding to the movement, extracting a first image before and after a stroke from the image, and generating the first image the server generating a second image by rotating based on the angle, generating a stroke image by separating a stroke region included in the second image, and transmitting the first image and the stroke image to a display unit; and
Billiard stroke replay image providing system, characterized in that it comprises the display unit for receiving and displaying the first image and the stroke image.

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