KR20210092659A - Method, system, and non-transitory computer-readable recording medium for measuring ball spin - Google Patents

Abstract

According to one aspect of the present invention, a method for measuring the rotation of a ball comprises the following steps of: detecting a plurality of dimples in each of a plurality of images of a ball that is a target of physical quantity measurement; and measuring the physical quantity related to the rotation of the ball by referring to a correlation between properties of a plurality of dimples detected in a first image among the plurality of images and properties of a plurality of dimples detected in a second image.

Description

METHOD, SYSTEM, AND NON-TRANSITORY COMPUTER-READABLE RECORDING MEDIUM FOR MEASURING BALL SPIN, METHOD, SYSTEM, AND NON-TRANSITORY COMPUTER-READABLE RECORDING MEDIUM FOR MEASURING BALL SPIN

The present invention relates to a method, system and non-transitory computer-readable recording medium for measuring the rotation of a ball.

A virtual golf system that allows golfers to virtually enjoy golf at a low cost even in a city center has been widely distributed. Such a virtual golf system, when a golfer hits a golf ball, acquires a plurality of images of the golf ball, measures a physical quantity about the golf ball based on the trajectory, interval, size, etc., and performs a simulation based on this to play golf The basic concept is to display the simulation result of the shot on the screen. In such a virtual golf system, it is important to obtain a photographed image of a golf ball in the best possible state.

In this regard, Korean Patent Application Laid-Open No. 10-2009-0112538 discloses a technique for acquiring more diverse images of a golf ball by shooting a golf practice scene while controlling the position or color of lighting (the above publication). (the specification of which is to be regarded as incorporated herein in its entirety). However, several conventional techniques including this technique are necessary to obtain a golf ball image in a good state required to accurately measure the physical quantity of a golf ball, but use dimples that can be obtained from a plurality of golf ball images. Therefore, it is true that there is no interest in the technology for measuring the physical quantity related to the rotation of a golf ball.

The present inventor(s) proposes a novel and advanced technology capable of accurately measuring a physical quantity related to rotation of a golf ball by analyzing dimples detected in a plurality of images of a golf ball obtained from a camera.

An object of the present invention is to solve all the problems of the prior art described above.

Another object of the present invention is to simply and accurately measure a physical quantity related to the rotation of a ball by analyzing dimples appearing over a plurality of ball images.

Another object of the present invention is to accurately measure the physical quantity related to the rotation of the ball even if there is no mark or mark on the ball that is the target of the physical quantity measurement.

A representative configuration of the present invention for achieving the above object is as follows.

According to an aspect of the present invention, there is provided a method for measuring the rotation of a ball, the method comprising: detecting a plurality of dimples in each of a plurality of images obtained by photographing a ball that is a target of physical quantity measurement, and among the plurality of images; A method is provided that includes measuring a physical quantity related to rotation of the ball with reference to a correlation between attributes of a plurality of dimples detected in a first image and attributes of a plurality of dimples detected in a second image.

According to another aspect of the present invention, as a system for measuring the rotation of a ball, a dimple detection management unit that detects a plurality of dimples in each of a plurality of images of a ball that is a target of physical quantity measurement, and the plurality of A system including a physical quantity measuring unit for measuring a physical quantity related to the rotation of the ball with reference to the correlation between the attributes of the plurality of dimples detected in the first image and the attributes of the plurality of dimples detected in the second image among the images is provided do.

In addition to this, another method for implementing the present invention, another system, and a non-transitory computer-readable recording medium for recording a computer program for executing the method are further provided.

According to the present invention, it is possible to simply and accurately measure the physical quantity related to the rotation of the ball by analyzing the dimples appearing over the plurality of ball images.

Further, according to the present invention, it is possible to accurately measure the physical quantity related to the rotation of the ball even if there is no mark or mark on the ball that is the target of the physical quantity measurement.

1 is a diagram illustrating in detail an internal configuration of a measurement system according to an embodiment of the present invention.
2 to 4 are diagrams exemplarily showing a preprocessing process that may be performed on each of a plurality of images in order to detect a dimple of a ball according to an embodiment of the present invention.
5 is a diagram exemplarily illustrating a situation in which a measurement system according to an embodiment of the present invention is utilized in a virtual golf simulation system according to an embodiment of the present invention.
6 is a view exemplarily illustrating a situation in which a physical quantity related to the rotation of a ball is measured according to an embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [0010] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [0010] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [0023] Reference is made to the accompanying drawings, which show by way of illustration specific embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the present invention. It should be understood that the various embodiments of the present invention are different but need not be mutually exclusive. For example, certain shapes, structures, and characteristics described herein may be implemented with changes from one embodiment to another without departing from the spirit and scope of the present invention. In addition, it should be understood that the location or arrangement of individual components within each embodiment may be changed without departing from the spirit and scope of the present invention. Accordingly, the following detailed description is not to be taken in a limiting sense, and the scope of the present invention should be taken as encompassing the scope of the claims and all equivalents thereto. In the drawings, like reference numerals refer to the same or similar elements throughout the various aspects.

Hereinafter, various preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings in order to enable those of ordinary skill in the art to easily practice the present invention.

Configuration of the measuring system

1 is a diagram illustrating in detail an internal configuration of a measurement system 100 according to an embodiment of the present invention.

1 , the measurement system 100 may include a dimple detection management unit 110 , a physical quantity measurement unit 120 , a communication unit 130 , and a control unit 140 . According to an embodiment of the present invention, the dimple detection and management unit 110 , the physical quantity measurement unit 120 , the communication unit 130 , and the control unit 140 are program modules in which at least some of them communicate with an external system (not shown). can be Such a program module may be included in the measurement system 100 in the form of an operating system, an application program module, or other program modules, and may be physically stored in various known storage devices. Also, such a program module may be stored in a remote storage device capable of communicating with the measurement system 100 . Meanwhile, such a program module includes, but is not limited to, routines, subroutines, programs, objects, components, data structures, etc. that perform specific tasks or execute specific abstract data types according to the present invention.

On the other hand, although described above with respect to the measurement system 100, these descriptions are exemplary, and at least some of the components or functions of the measurement system 100 are realized in a known virtual golf simulation system or known virtual as needed. It will be apparent to those skilled in the art that it may be included in a golf simulation system. In addition, in some cases, all functions and all components of the measurement system 100 may be fully executed in a known virtual golf simulation system or all included in a known virtual golf simulation system.

First, the dimple detection management unit 110 according to an embodiment of the present invention may perform a function of detecting a plurality of dimples in each of a plurality of images obtained by photographing a ball that is a target of physical quantity measurement.

For example, the dimple detection management unit 110 may perform pre-processing for improving identification of the plurality of dimples on each of the plurality of images taken above, and the plurality of dimples based on the plurality of pre-processed images can be detected.

More specifically, the dimple detection manager 110 performs blur, histogram equalization, contrast, adaptive thresholding binarization, and morphology for each of the plurality of images 210 . ), stabilization, noise removal, quality improvement, etc. of the plurality of images above may be performed by performing at least one preprocessing. On the other hand, the above pre-processing process may be performed based on a window having the same or similar size as that of the dimple of the ball, for example, at least one window having a size equal to or similar to the size of the dimple of the ball. For each of a plurality of images (or around a region estimated as a dimple within each image) based on a filter of (e.g., a filter for processing at least one of blur, contrast, adaptive threshold binarization, and morphology) Processing (eg, a convolution operation between the filter and the image) may be performed.

For example, referring to FIG. 2 , a pre-processing process performed on each of the plurality of images 210 according to an embodiment of the present invention will be described in detail. (1) First, the dimple detection management unit 110 may Blur processing to reduce noise may be performed on each image of . (2) Next, the dimple detection management unit 110 may perform a contrast process on each of the plurality of images to increase the contrast while maintaining the same brightness as the original image ( 220 ). Looking at the above contrast processing in detail with reference to FIG. 3 , based on a Gaussian filter (specifically, a normal Gaussian filter) 310 for the contrast processing, the center of the filter (specifically, the center and 320), and offset so that the overall distribution mean of the filter remains at a certain level (e.g., 0 or 1, but the same level as before increasing the size as above). By applying the filtered filter 330 (eg, in which the filter is parallelly moved in the negative direction), the average brightness in each of the plurality of images 220 may be maintained while the contrast may be increased. (3) Then, the dimple detection management unit 110 may perform the adaptive threshold binarization process on each of the plurality of images (specifically, centered on each dimple region in each image region) (230) . For example, analyzing the pixel brightness with respect to the adjacent area of each dimple (eg, calculating the average brightness for each pixel at the adaptive threshold of each dimple specified in each of the plurality of images above) calculation, and the threshold value of each dimple is calculated based on the brightness average) to perform the binarization process, so that each dimple region can be more clearly specified. Meanwhile, in the process of analyzing the pixel brightness, instead of re-calculating the sum for calculating the above brightness average, the processing is performed based on information on an accumulation map that can be accumulated and managed for the entire area. By doing so, it is possible to reduce the computational load. (4) Then, the dimple detection management unit 110 may perform a morphology operation on each of the plurality of images, so that each dimple region appears more clearly in each of the plurality of images. (5) Then, in each of the plurality of images, the area corresponding to the dimple of the ball by light (eg, infrared LED light or sunlight applied for camera photography) applied to the ball while the ball is being photographed. Since this area appears brighter than other areas, the dimple detection management unit 110 may detect a plurality of dimples (specifically, the position of each dimple in the empty image) based on the bright area in each of the plurality of images ( 240). (6) Meanwhile, the dimple detection management unit 110 may correct the position of the dimple in each of the plurality of images based on a direction in which light is applied to the ball detected in each of the plurality of images. For example, referring to FIG. 4 , when a plurality of dimples 401 are detected based on a bright area in each of the plurality of images as above, the position 410 of the dimples detected in each of the plurality of images is on the ball. There may be an error compared to the actual position 420 of the dimple due to the shape of the ball (or the dimple 401 ) depending on the direction in which light is applied. For example, as the difference between the angle between the normal of each dimple 401 and the direction in which light is applied increases due to the ball and the curvature of the dimples 401, the darker area (ie, the area where light does not reach) 402 ) increases and the bright region 403 decreases, and the position 410 of the center of the bright region 403 has a larger error with respect to the position 420 of the center of the actual dimple. Accordingly, the dimple detection management unit 110 gives a predetermined offset to the position of the dimple 401 detected as above based on the direction in which the light is applied (specifically, the position of the center of the bright area 403). The position of each dimple 401 in each of the plurality of images may be more accurately specified. More specifically, the brightness in each of the plurality of images is centered on the diameter d (or radius) of the dimple 401 and the angle θ formed by the opening surface of the dimple 401 with a predetermined point (eg, the ground). By providing an offset so that the position 410 of the center of the region coincides with the position 420 of the center of the actual dimple, the position of each dimple 401 in each of the plurality of images may be more accurately detected. Meanwhile, the magnitude of such an offset may be specified based on a sin function or a cos function, for example, k·d·sin(2θ)/4 (here, k is a predetermined weight). Meanwhile, when an additional light source (eg, sunlight) exists, the position of the dimple may be corrected with further reference to the position of the additional light source. For example, when sunlight is applied in addition to indoor lighting, such as outdoors, a process similar to the process described above with reference to the location where the sunlight is applied (eg, specified with reference to information about the altitude of the sun) By performing , the positions of the dimples detected in the plurality of images may be further corrected. Meanwhile, when indoor lighting is not used and only sunlight is applied, the position of the dimple may be corrected in consideration of only the position to which the sunlight is applied.

On the other hand, when the dimple detection management unit 110 detects at least one mark (eg, a logo, a mark, etc.) appearing in an area corresponding to the ball in each of a plurality of images of a ball that is a target of physical quantity measurement , the at least one indicia may be specified as at least one dimple.

For example, the dimple detection management unit 110 fragments the edge of the detected mark to a degree similar to the average distance between the dimples, and processes each piece to represent one dimple, so that the corresponding mark is analyzed in the same manner as the dimples described above. can be specified (240). In this case, since the location of the dimple can be specified differently depending on where the starting point of dividing the mark as above is the dimple, the starting point for slicing the border is the point where the influence can be minimized even when the ball is rotated (e.g. For example, this point may be specified with reference to a point of maximum curvature and a point of minimum curvature, which may be determined with reference to).

At least one mark detected in each of the above plurality of images usually corresponds to a dark color, and unlike dimples, there is little difference in brightness, so it is somewhat difficult to specify as a dimple from the corresponding area, but the at least one mark is a dimple and a dimple. Since it can be utilized in the same way, it is possible to prepare for a situation where the number of dimples detected in the ball is small.

Next, the physical quantity measuring unit 120 according to an embodiment of the present invention determines the correlation between the attributes of the plurality of dimples detected in the first image among the plurality of images and the attributes of the plurality of dimples detected in the second image. With reference to it, the function of measuring the physical quantity related to the rotation of the ball can be performed. The attribute of a dimple according to an embodiment of the present invention may be a concept including a distance relation, a position relation, a direction relation, and the like between the dimples. Further, according to an embodiment of the present invention, the physical quantity related to the rotation of the ball may include information about the rotation direction, rotation speed, rotation acceleration, rotation angular velocity, rotation amount, and the like of the ball. However, it should be noted that the physical quantity related to the rotation of the ball according to the present invention is not necessarily limited to the information listed above, and can be variously changed within the range that can achieve the object of the present invention. Also, the relation between the attributes of the plurality of dimples according to an embodiment of the present invention may be a concept indicating to what extent the attributes of the plurality of dimples are physically, spatially, numerically, or logically identical to or similar to each other.

For example, the physical quantity measuring unit 120 may determine an attribute of at least one pair of dimples (the pair of dimples may consist of at least two dimples) specified from the plurality of dimples of the first image and the plurality of dimples of the second image. At least one first linked dimple pair is determined based on the matching degree by comparing the properties of at least one dimple pair specified from You can measure the physical quantity related to the rotation of According to an embodiment of the present invention, the degree of matching is determined based on various minimum error calculation methods such as root mean square error between attributes of a dimple pair, mean absolute value percent error, and singular value decomposition of a matrix. can be However, it should be noted that the degree of matching according to the present invention is not limited to the above-listed methods, and can be variously changed to a score (or weighted score) method, etc. within a range that can achieve the object of the present invention. . Also, the first linked dimple pair according to an embodiment of the present invention may be configured to include a dimple pair of each of at least two images. For example, the first pair of dimples of the first image based on the above matching degree. and a third pair of dimples of the second image, a second pair of dimples of the first image, and a fifth pair of dimples of the second image may be determined as the above first associated dimple pair, respectively. In addition, the rotation information of the first linked dimple pair according to an embodiment of the present invention may be a concept including information about whether the first linked dimple pair is matched when the degree of rotation is made. For example, when the first pair of dimples is rotated by 30 degrees, it matches the third pair of dimples, and when the second pair of dimples is rotated by 40 degrees, it matches the fifth pair of dimples. Information about 30 degrees and 40 degrees, which are angles to be rotated, can be specified as the above rotation information.

More specifically, it is assumed that a predetermined rotation (specifically, rotation of a ball) occurs with respect to at least one pair of dimples in the first image (or at least one pair of dimples in the second image) of the physical quantity measuring unit 120 . Thus, at least one dimple pair of the second image (or at least one dimple pair of the first image) and (1) the degree to which the midpoints of each dimple pair coincide with each other, (2) a straight line connecting each dimple pair (or line segments) coincide with each other, (3) a first axis connecting the first dimple from a predetermined (or arbitrary) point, a second axis connecting the second dimple from a predetermined point above, and a first axis above and a third axis specified based on the second axis (eg, a normal axis) by comparing the properties between the above dimple pairs based on the degree to which three axes of each dimple pair coincide with each other, etc. By analyzing (eg, analyzing by comparing whether a minimum error occurs), a predetermined number (eg, top 10% or 5) of dimple pairs in the first image and dimple pairs in the second image based on the degree of matching may be determined as the first pair of associated dimples above. More specifically, when 10 dimples are specified in the first image, a total of 45 dimple pairs may be specified, and when 10 dimples are specified in the second image, a total of 45 dimple pairs may be specified as in the first image. In this case, the comparison between the attributes of each dimple pair may be performed a total of 2,025 times (ie, 45 X 45 times).

Meanwhile, the physical quantity measuring unit 120 according to an embodiment of the present invention determines a dimple pair having a distance between dimples within a predetermined range among at least one dimple pair specified from each of a plurality of images as a valid dimple pair, and the valid The computational load may be reduced by determining the first associated dimple pair based on the dimple pair.

That is, when the distance between the dimples is equal to or less than the first distance (that is, when the distance between the dimples is close to or less than a predetermined level), the distance between the dimples is quite close, so an error (e.g., each error) is high, and when the distance between the dimples is greater than or equal to the second distance (the second distance is set greater than the first distance above) (that is, when the distance between the dimples is farther than a predetermined level) As the ball rotates, there is a high probability that a pair of dimples with a high degree of matching is not detected in an adjacent image. Therefore, only a pair of dimples with a distance between the dimples within a predetermined range is determined as a valid dimple, and based on this, the first linked dimple pair is determined can decide Meanwhile, the above predetermined range may be preset or dynamically specified with reference to a probability that a dimple pair is detected in the image of the ball (eg, associated with the surface area of the ball).

In addition, according to an embodiment of the present invention, a dimple pair specified from a plurality of images is not necessarily specified in each image as a whole as in the above-listed embodiments, and each image is within a range that can achieve the object of the present invention. By specifying the dimple pair with respect to a predetermined region within the dimple, it is possible to reduce the computational load and improve the computational speed. The predetermined region in the above image may be identical for each image or may be specified in consideration of a range in which the region may be rotated between temporally adjacent images.

In addition, the physical quantity measuring unit 120 specifies a predetermined rotation range rotatable between the dimple pair of the first image and the dimple pair of the second image, and the above predetermined one of the at least one first linked dimple pair determined above. A pair of associated dimples existing within the rotation range may be determined as the at least one first pair of associated dimples above. For example, according to an embodiment of the present invention, the maximum rotation range of the ball per image frame between adjacent images may be calculated with reference to the maximum number of rotations of the ball and the frame rate of a camera photographing the ball. may be, and the above predetermined rotation range may be specified based on this.

In addition, the physical quantity measuring unit 120, in order to more accurately specify the physical quantity related to the rotation of the ball, a plurality of the first image and the second image calculated based on the rotation information of the above at least one first linked dimple pair. At least one second linked dimple pair is determined from among the above at least one first linked dimple pair based on the matching degree between the dimples of , and rotation information of the determined second linked dimple pair is used to rotate the ball. It is also possible to measure physical quantities related to

More specifically, the physical quantity measuring unit 120 is configured to rotate the dimple pair of the first image among the at least one first linked dimple pair to the corresponding dimple pair of the second image temporally adjacent to the first image. When the plurality of dimples of the first image are rotated, the degree of matching of the plurality of dimples of the first image with the plurality of dimples of the second image is compared and analyzed, and the at least one second image is analyzed based on the degree of matching. A predetermined number (eg, top 10%) of dimple pairs among 1 linked dimple pairs are determined as the above second linked dimple pairs, and rotation information of the determined second linked dimple pairs is referred to for rotation of the ball. A physical quantity can be measured.

In addition, the physical quantity measuring unit 120 is configured to rotate the dimple pair of the first image among the at least one first linked dimple pair to the corresponding dimple pair of the third image spaced apart in time from the first image by a predetermined level. When each dimple specified in the first image is rotated, the degree to which each dimple specified in the first image matches each dimple specified in the third image is compared and analyzed, and at least the above based on the matching degree A predetermined number of (eg, top 10%) dimple pairs among one first linked dimple pair are determined as the above second linked dimple pairs, and further refer to rotation information of the determined second linked dimple pairs. A second linked dimple pair specified between the examined temporally adjacent images may be determined, or a physical quantity related to the rotation of the ball may be measured by referring to rotation information of the determined second linked dimple pair.

On the other hand, in order to reduce the computational load in the process of comparing the matching degree between the plurality of dimples of the first image and the plurality of dimples of the second image as described above, at least one first linked dimple pair exists in each image. The above matching degree can be quickly and simply determined by specifying . For comparative analysis centered on the above-mentioned adjacent region, various methods such as pseudoinverse or singular value decomposition of the matrix may be used. In addition, a region in each image may be divided into a plurality of regions based on theta-phi criteria, X, Y, Z coordinate criteria, Fibonacci lattice criteria, and the like, and the at least one first An adjacent region may be specified around a point at which an associated dimple pair exists.

Next, the communication unit 130 according to an embodiment of the present invention may perform a function of enabling data transmission/reception to/from the dimple detection management unit 110 and the physical quantity measurement unit 120 .

Finally, the control unit 140 according to an embodiment of the present invention may perform a function of controlling the flow of data between the dimple detection management unit 110 , the physical quantity measurement unit 120 , and the communication unit 130 . That is, the control unit 140 controls the data flow to/from the outside of the measurement system 100 or the data flow between each component of the measurement system 100 , thereby controlling the dimple detection management unit 110 and the physical quantity measurement unit 120 . and the communication unit 130 may be controlled to perform a unique function, respectively.

5 is a diagram exemplarily illustrating a situation in which the measurement system 100 according to an embodiment of the present invention is utilized in the virtual golf simulation system 200 according to an embodiment of the present invention.

5, the virtual golf simulation system 200 includes a striking unit 10, The lighting device 20 , the photographing device 210 , the simulator 220 , and the display device 230 may be included. In addition, the simulator 220 according to an embodiment of the present invention may include the measurement system 100 according to the present invention.

First, the striking unit 10 according to an embodiment of the present invention may be a part where a golfer puts and hits a golf ball while stepping on their feet when using the virtual golf simulation system 200 . The striking unit 10 may include a known swing plate whose inclination angle can be adjusted. For reference, when the present invention is applied to other types of virtual sports simulator systems, those skilled in the art can determine the configuration of the striking unit 10, if necessary, along with the configuration of other components interlocking therewith, depending on the characteristics of the sport. You can change it to suit you.

Next, the lighting device 20 according to an embodiment of the present invention may be a device capable of artificially irradiating light when a golfer enjoys virtual golf indoors or outdoors. The lighting device 20 may be turned on and off or its brightness may be adjusted as needed. Preferably, the lighting device 20 may be an infrared light (eg, LED) for preventing the natural deterioration of the golf ball image due to the vibration of light.

Next, the photographing device 210 according to an embodiment of the present invention includes at least one camera (eg, a high-speed camera) (not shown) and an image of a golf ball (eg, golf in motion) The function of acquiring two or more images of the ball) can be performed. The photographing device 210 may be disposed at a position looking down at the golf ball in motion as shown in FIG. 5 , or may be disposed at other positions.

On the other hand, the photographing apparatus 210 according to an embodiment of the present invention implements a performance similar to that of a high-speed camera by sequentially acquiring images of a golf ball using at least two cameras (not shown) having different photographing speeds. may be That is, in this case, since the above at least two cameras do not need to be synchronized with each other, it may not be necessary to provide expensive equipment.

On the other hand, according to an embodiment of the present invention, the image of the golf ball is clearly formed with a predetermined dimple on the surface of the photographed golf ball, so it can be said that the better the dimple is, the better it is. For example, the clearer the dimples formed in the area corresponding to the ball in the image of the golf ball, the more accurately the simulator 220 as described below can capture the dimples appearing across a plurality of images of the golf ball. Physical quantities (eg, rotation speed and rotation direction) can be calculated more accurately.

Next, the simulator 220 according to an embodiment of the present invention detects a plurality of dimples in each of a plurality of images obtained by photographing a ball that is a target of physical quantity measurement, and detects a plurality of dimples in the first image among the plurality of images. A function of measuring a physical quantity related to the rotation of the ball may be performed by referring to the correlation between the attributes of the plurality of dimples and the attributes of the plurality of dimples detected in the second image.

Meanwhile, the simulator 220 according to an embodiment of the present invention may communicate with the photographing device 210 and the display device 230 , and may include a dedicated processor for the virtual golf simulation 200 . Such a dedicated processor may be provided with a memory means and equipped with numerical arithmetic and graphic processing capabilities.

Finally, the display device 230 according to an embodiment of the present invention may perform a function of displaying the results of measuring a physical quantity of the simulator 220 and realizing virtual reality. The display device 230 may display a predetermined image through a predetermined display means, for example, a screen that absorbs the impact of a hit golf ball while not directly emitting light, and a screen that outputs an image to the screen It may consist of a projector.

Hereinafter, a process of measuring a physical quantity related to rotation of a golf ball when a user hits a golf ball using the virtual golf simulation system 200 described above will be described below.

First, when a golf ball is hit by a user in the striking unit 10 according to an embodiment of the present invention, a plurality of images of the golf ball hit by the photographing device 210 may be acquired.

Then, the simulator 220 according to an embodiment of the present invention calculates blur, contrast, and/or contrast for each of the plurality of images above based on at least one filter having a window of a size equal to or similar to the size of the dimple of the ball. At least one of adaptive threshold binarization and morphology may be preprocessed.

Next, the simulator 220 according to an embodiment of the present invention performs a bright area (ie, five images adjacent in time) specified in each of a plurality of images (eg, temporally adjacent five images) of a ball that is a target of physical quantity measurement. , a plurality of dimples may be detected based on an area brightly displayed by the light applied by the lighting device 20 above.

Then, the simulator 220 according to an embodiment of the present invention configures the attribute of at least one dimple pair specified from the plurality of dimples of the first image among the plurality of images and the second image among the plurality of images. By comparing and analyzing the attributes of at least one dimple pair specified from the plurality of dimples of , it is possible to determine a plurality of first linked dimple pairs corresponding to the top 10% based on the matching degree (ie, rough search). (coarse search) to determine the first pair of associated dimples).

Thereafter, the simulator 220 according to an embodiment of the present invention performs a function between the plurality of dimples of the first image and the second image calculated based on the rotation information of the plurality of first linked dimple pairs. Based on the matching degree, a second linked dimple pair having the highest matching degree may be determined among the plurality of first linked dimple pairs (that is, the second linked dimple pair is determined by a fine search method) ). The above first image and the second image may include both images that are temporally adjacent or temporally separated by a predetermined level based on the acquisition time.

For example, a second pair of associative dimples between a first image of the plurality of images and a second temporally adjacent image, a second between a second image of the plurality of images and a third temporally adjacent image Both the associated dimple pair and the second associated dimple pair between the first image and the third image separated by a predetermined level from among the plurality of images above may be determined, respectively.

Then, the simulator 220 according to an embodiment of the present invention refers to the rotation information of the second linked dimple pair having the highest matching degree among the above second linked dimple pairs, and the rotation amount and rotation of the ball. direction can be measured.

6 is a view exemplarily illustrating a situation in which a physical quantity related to rotation of a ball is measured according to an embodiment of the present invention.

Referring to FIG. 6 , a plurality of dimples may be detected in each of a plurality of images (ie, a first image, a second image, and a third image) obtained by photographing a ball that is a target of physical quantity measurement. The first to third images may be sequentially acquired and temporally adjacent images, respectively.

Then, from the plurality of dimples (1-1 dimple 611, 1-2 dimple 612, 1-3 dimple 613, and 1-4 dimple 614) of the first image. dimple pair of (1) 1-1 dimple 611 <-> 1-2 dimple 612, (2) 1-2 dimple 612 <-> 1-3 dimple 613 , (3) 1-3 dimple (613) <-> 1-4 dimple (614), (4) 1-1 dimple (611) <-> 1-3 dimple (613), (5) 1-1 dimple 611 <-> 1-4 dimple 614 and (6) 1-2 dimple 612 <-> 1-4 dimple 614 is specified, a plurality of dimple pairs from a plurality of dimples (2-1 dimple 621 , 2-2 dimple 622 , 2-3 dimple 623 , and 2-4 dimple 624 ), namely (1) 2-1 dimple 621 <-> 2-2 dimple 622, (2) 2-2 dimple 622 <-> 2-3 dimple 623, (3) 2-3 dimple 623 <-> 2-4 dimple 624, (4) 2-1 dimple 621 <-> 2-3 dimple 623, (5) 2-1 dimple 621 <-> 2-4 dimples 624 and (6) 2-2 dimples 622 <-> 2-4 dimples 624 are specified, and a plurality of dimples (3-1 dimple 631 , 3-2 dimple 632 , 3-3 dimple 633 , and 3-4 dimple 634 ) from a plurality of pairs of dimples, namely (1) 3-1 dimple 631 ). <-> 3-2 dimples 632, (2) 3-2 dimples 632 <-> 3-3 dimples 633, (3) 3-3 dimples 633 <-> th 3-4 dimple (634), (4) 3-1 dimple (631) <-> 3-3 dimple (633), (5) 3-1 dimple (631) <-> 3-4 dimple (634) and (6) 3-2 dimple 632 <-> 3-4 dimple 634 may be specified.

Then, an attribute of the plurality of dimple pairs specified from the plurality of dimples of the first image (eg, 601 ) and an attribute of the plurality of dimple pairs specified from the plurality of dimples of the second image (eg, 602 ) ) by comparing with each other, at least one pair of first associated dimples may be determined based on the matching degree. In addition, an attribute of a plurality of dimple pairs specified from a plurality of dimples of the second image (eg, 602) and an attribute of a plurality of dimple pairs specified from a plurality of dimples of the third image (eg, 603) By comparing and analyzing each other, at least one pair of first associated dimples may be determined based on the matching degree. In addition, an attribute of a plurality of dimple pairs specified from a plurality of dimples of the first image (eg, 601) and an attribute of a plurality of dimple pairs specified from a plurality of dimples of the third image (eg, 603) By comparing and analyzing each other, at least one pair of first associated dimples may be determined based on the matching degree. According to an embodiment of the present invention, the properties of the above dimple pair include a first axis connecting the first dimples of the corresponding dimple pair from a predetermined (or arbitrary) point, and a first axis of the corresponding dimple pair from the above predetermined point. It may be specified based on a second axis connecting the two dimples and a third axis (eg, a normal axis) specified based on the first and second axes.

For example, assuming that a predetermined rotation occurs with respect to a plurality of pairs of dimples of the first image, the properties of each pair of dimples for the plurality of pairs of dimples of the second image, that is, the above three axes are matched with each other By comparing and analyzing the degree (for example, analyzing by comparing whether a minimum error occurs), a predetermined number (for example, the top two) of the dimple pair of the first image and the second image based on the matching degree A dimple pair may be determined as the first associated dimple pair above.

More specifically, according to an embodiment of the present invention, the 1-1 dimple 611 <-> the 1-2 dimple 612 and the 2-2 dimple 622 <-> the 2-3 dimple ( 623) and the 1-1 dimple 611 <-> the 1-4 dimple 614 and the 2-1 dimple 621 <-> the 2-4 dimple 624 are the first linked dimples above, respectively can be determined as a pair.

Then, based on the degree of matching between the plurality of dimples of the first image and the second image calculated based on the rotation information of the at least one first associated dimple pair, the at least one first associated dimple pair At least one second associated dimple pair may be determined among the pairs. In addition, based on the degree of matching between the plurality of dimples of the first image and the third image calculated based on the rotation information of the at least one first linked dimple pair, among the at least one first linked dimple pair At least one second pair of associated dimples may be determined. In addition, based on the degree of matching between the plurality of dimples of the second image and the third image calculated based on the rotation information of the at least one first linked dimple pair, among the at least one first linked dimple pair At least one second pair of associated dimples may be determined.

For example, when the 1-1 dimple 611 <-> the 1-2 dimple 612 is rotated to a certain extent, the 1-1 dimple 611 <-> the 1-2 dimple 612 is rotated to a certain extent. A first image for each of the at least one first linked dimple pair above with reference to information on whether the attribute and the 2-2 dimple 622 <-> the attribute of the 2-3 dimple 623 match each other and a degree to which a plurality of dimples of the second image are matched may be calculated. In addition, when the 1-1 dimple 611 <-> the 1-4 dimple 614 is rotated to a certain extent, the properties of the 1-1 dimple 611 <-> the 1-4 dimple 614 and With reference to information on whether the properties of the 2-1 dimple 621 <-> the 2-4 dimple 624 match each other, the first image and the second dimple pair for each of the above at least one first linked dimple pair 2 It is possible to calculate a degree to which a plurality of dimples of an image are matched. According to this process, the 1-1 dimple 611 <-> the 1-4 dimple 614 and the 2-1 th dimple 614 are calculated to have the highest matching degree of the plurality of dimples of the first image and the second image. Dimples 621 <-> 2-4 dimples 624 may be determined as the second pair of linked dimples. Meanwhile, the process of determining the second linked dimple pair as described above may be further performed on the second image and the third image, and the first image and the third image.

Then, a physical quantity related to the rotation of the ball may be measured with reference to the above determined rotation information of the second linked dimple pair.

Specifically, at least one second pair of associative dimples determined between the first image and the second image, at least one second pair of associative dimples determined between the second image and the third image, and the first image and the third image A physical quantity related to the rotation of the ball may be measured with reference to rotation information of a second linked dimple pair having the highest matching degree among at least one second linked dimple pair determined between the two dimple pairs.

For example, among the above second linked dimple pairs, 1-1 dimple 611 <-> 1-4 dimple 614 and 2-1 dimple 621 <-> 2-4 dimple 624 ) is determined as the second linked dimple pair with the highest matching degree, the 1-1 dimple 611 when the 1-1 dimple 611 <-> the 1-2 dimple 612 rotates to a certain extent <-> the rotation speed of the ball with reference to information on whether the properties of the 1-2 dimple 612 and the 2-2 dimple 622 <-> the properties of the 2-3 dimple 623 match each other; A rotation amount, rotational acceleration, etc. may be calculated, and a physical quantity related to the rotation of the ball may be measured based on this.

The embodiments according to the present invention described above may be implemented in the form of program instructions that can be executed through various computer components and recorded in a computer-readable recording medium. The computer-readable recording medium may include program instructions, data files, data structures, etc. alone or in combination. The program instructions recorded on the computer-readable recording medium may be specially designed and configured for the present invention, or may be known and available to those skilled in the art of computer software. Examples of the computer-readable recording medium include hard disks, magnetic media such as floppy disks and magnetic tapes, optical recording media such as CD-ROMs and DVDs, and magneto-optical media such as floppy disks. medium), and hardware devices specially configured to store and execute program instructions, such as ROM, RAM, flash memory, and the like. Examples of program instructions include not only machine language codes such as those generated by a compiler, but also high-level language codes that can be executed by a computer using an interpreter or the like. A hardware device may be converted into one or more software modules to perform processing in accordance with the present invention, and vice versa.

In the above, the present invention has been described with reference to specific matters such as specific components and limited embodiments and drawings, but these are provided to help a more general understanding of the present invention, and the present invention is not limited to the above embodiments, Those of ordinary skill in the art to which the invention pertains can make various modifications and changes from these descriptions.

Therefore, the spirit of the present invention should not be limited to the above-described embodiments, and the scope of the spirit of the present invention is not limited to the scope of the scope of the present invention. will be said to belong to

100: measuring system
110: dimple detection management unit
120: physical quantity measurement unit
130: communication department
140: control unit
200: virtual golf simulation system
210: photographing device
220: simulator
230: display device

Claims (13)

A method for measuring the rotation of a ball, comprising:
Detecting a plurality of dimples in each of a plurality of images of a ball that is a target of physical quantity measurement, and
Measuring a physical quantity related to the rotation of the ball with reference to a correlation between attributes of a plurality of dimples detected in a first image among the plurality of images and attributes of a plurality of dimples detected in a second image
method. According to claim 1,
In the detection step, by applying to each of the plurality of images at least one filter having a window of a size equal to or similar to the size of the dimples of the ball, preprocessing for improving the discrimination power of the plurality of dimples to do
method. According to claim 1,
In the detection step, a preprocessing of increasing the contrast of the plurality of images is performed by increasing the size of the center by a predetermined level based on the Gaussian filter and applying a filter offset so that the average of the distribution is maintained at a predetermined level.
method. According to claim 1,
In the detecting step, correcting positions of a plurality of dimples detected in each of the plurality of images with reference to a direction in which light is applied to the ball in each of the plurality of images
method. According to claim 1,
The measuring step is
The attribute of at least one dimple pair among the plurality of dimples detected in the first image and the attribute of at least one dimple pair among the plurality of dimples detected in the second image are compared with each other, and at least one dimple pair is selected based on the matching degree. determining a pair of associated dimples, and
Measuring a physical quantity related to the rotation of the ball with reference to the rotation information of the at least one linked dimple pair
method. According to claim 1,
The measuring step is
The attribute of at least one dimple pair among the plurality of dimples detected in the first image and the attribute of at least one dimple pair among the plurality of dimples detected in the second image are compared with each other, and at least one dimple pair is selected based on the matching degree. determining a first pair of associated dimples; and
At least one of the at least one first linked dimple pair based on the degree of matching between the plurality of dimples of the first image and the second image calculated based on rotation information of the at least one first linked dimple pair determining a second pair of associated dimples; and
Measuring a physical quantity related to the rotation of the ball with reference to rotation information of the at least one second linked dimple pair
method. A non-transitory computer-readable recording medium storing a computer program for executing the method according to claim 1 . A system for measuring the rotation of a ball, comprising:
A dimple detection management unit that detects a plurality of dimples in each of a plurality of images of a ball that is a target of physical quantity measurement, and
A physical quantity measuring unit for measuring a physical quantity related to the rotation of the ball with reference to the correlation between the attributes of the plurality of dimples detected in the first image among the plurality of images and the attributes of the plurality of dimples detected in the second image
system. 9. The method of claim 8,
The dimple detection management unit is configured to apply at least one filter having a window having a size equal to or similar to the size of the dimples of the ball to each of the plurality of images, thereby improving discrimination of the plurality of dimples. performing pre-processing
system. 9. The method of claim 8,
The dimple detection management unit increases the size of the center by a predetermined level based on the Gaussian filter and applies a filter offset so that the average of the distribution is maintained at a predetermined level, thereby increasing the contrast of the plurality of images. doing
system. 9. The method of claim 8,
The dimple detection management unit is configured to correct positions of a plurality of dimples detected in each of the plurality of images with reference to a direction in which light is applied to the ball in each of the plurality of images.
system. 9. The method of claim 8,
The physical quantity measuring unit compares an attribute of at least one pair of dimples among a plurality of dimples detected in the first image with an attribute of at least one pair of dimples among a plurality of dimples detected in the second image to determine the degree of matching determining at least one linked dimple pair as a reference, and measuring a physical quantity related to the rotation of the ball with reference to rotation information of the at least one linked dimple pair
system. 9. The method of claim 8,
The physical quantity measuring unit compares an attribute of at least one pair of dimples among a plurality of dimples detected in the first image with an attribute of at least one pair of dimples among a plurality of dimples detected in the second image to determine the degree of matching At least one first linked dimple pair is determined as a reference, and a matching degree between a plurality of dimples of the first image and the second image calculated based on rotation information of the at least one first linked dimple pair is a criterion to determine at least one second linked dimple pair from among the at least one first linked dimple pair, and measure a physical quantity related to rotation of the ball with reference to rotation information of the at least one second linked dimple pair
system.

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