Golf swing diagnosis system

• US 20050143183A1
• Filed: 10/04/2004
• Published: 06/30/2005
• Est. Priority Date: 12/26/2003
• Status: Active Grant

• Current Assignee: Nobutaka Shimada, Sumitomo Rubber Industries Limited, Yoshiaki Shirai
• Original Assignee: SRI Sports Limited (Sumitomo Rubber Industries Limited)
• Inventors: Onuki, Masahide, Shirai, Yoshiaki, Ueda, Masahiko, Shimada, Nobutaka
• Granted Patent: US 7,502,491 B2
• Time in Patent Office: Days
• US Class Current: 473/151
• CPC Class Codes: A63B 2024/0012 Comparing movements or motion sequences with a registered reference
• CPC Class Codes: A63B 2024/0031 at the starting point
• CPC Class Codes: A63B 2071/0647 Visualisation of executed movements
• CPC Class Codes: A63B 2220/05 Image processing for measuring physical parameters
• CPC Class Codes: A63B 2220/24 Angular displacement
• CPC Class Codes: A63B 2220/30 Speed
• CPC Class Codes: A63B 2220/805 Optical or opto-electronic sensors
• CPC Class Codes: A63B 2220/807 Photo cameras
• CPC Class Codes: A63B 2220/808 Microphones
• CPC Class Codes: A63B 2220/836 Sensors arranged on the body of the user
• CPC Class Codes: A63B 24/0003 Analysing the course of a movement or motion sequences during an exercise or trainings sequence, e.g. swing for golf or tennis
• CPC Class Codes: A63B 24/0006 Computerised comparison for qualitative assessment of motion sequences or the course of a movement
• CPC Class Codes: A63B 24/0021 Tracking a path or terminating locations
• CPC Class Codes: A63B 69/3658 Means associated with the ball for indicating or measuring, e.g. speed, direction
• CPC Class Codes: A63B 71/06 Indicating or scoring devices for games or players , or for other sports activities

Abstract

A computer (15) captures the colored moving image of the golfer (11) who swings by gripping a golf club (12) having colored marks (M1 through M3) attached to a shaft (12a) thereof. The computer (15) converts the colored moving image into a plurality of still images; executes binarization for each pixel of a plurality of the still images by using a specific threshold of color information and recognizes pixels, of the still images, which satisfy the threshold as positions of the colored marks (M1 through M3) and extracts a movement of the shaft (12a) by using a movement vector amount of one of the colored marks (M1 through M3 ) or by using a vector angle between two of the colored marks (M1 through M3). In this manner, the computer (15) automatically extracts check-point images.

Claims

1. A golf swing diagnosis system comprising a computer for capturing a colored moving image obtained by photographing a golfer who swings by gripping a golf club having colored marks attached to a shaft thereof,

wherein said computer comprises:

a means for converting said colored moving image into a plurality of still images;

a means for executing binarization for each pixel of a plurality of said still images by using a specific threshold of color information and recognizing pixels, of said still images, which satisfy said threshold as positions of said colored marks so as to obtain coordinate data of each of said colored marks;

an operation extraction means for recognizing a movement of said golf club shaft by using a movement vector amount of one of said colored marks computed based on said coordinate data of each of said colored marks or by using a vector angle between two of said colored marks;

an image extraction means for selectively extracting still images necessary for diagnosing a golf swing from a plurality of said still images, based on data obtained by said operation extraction means; and

an output means for outputting said extracted still image.

2. The golf swing diagnosis system according to claim 1, wherein said the extracted still images necessary for diagnosing said golf swing are check-point images including an impact image and one or more swing postures other than said impact image.

3. The golf swing diagnosis system according to claim 1, wherein said operation extraction means automatically traces a position of each of said colored marks of each still image by storing automatically recognized color information of red, green, and blue of each of said colored marks of one still image as reference color information;

sets an allowable range of a color regarded as the same color as said reference color;

sets on a subsequent frame a search range which is a region including an estimated position of each of said colored marks in a still image of said subsequent frame adjacent to said one still image in time series; and

regards pixels falling in said color range as said positions of said colored marks in said search range.

4. The golf swing diagnosis system according to claim 3, wherein when said colored marks cannot be traced, binarization is executed again on each pixel in said search range by using said specific threshold of said color information to obtain coordinate data by regarding pixels satisfying said threshold as positions of said colored marks.

5. The golf swing diagnosis system according to claim 1, wherein said operation extraction means extracts a swing posture by using a movement vector amount between still images, of one of said colored marks provided on said shaft, adjacent to each other in time series;

said image extraction means extracts a still image at an impact time and one or more images of a swing posture selected from among a take-back shaft 9 o'"'"'clock image, a top image, a downswing shaft 9 o'"'"'clock image, a follow-through shaft 3 o'"'"'clock image, and a finish image as check-point images.

6. The golf swing diagnosis system according to claim 1, wherein said operation extraction means extracts a swing posture by using a vector angle between two or more of said colored marks provided on said shaft at certain intervals or/and a movement vector amount of one of said colored marks near a grip;

and

said image extraction means extracts a still image at an impact time and one or more images of a swing posture selected from among a take-back shaft 9 o'"'"'clock image, a top image, a downswing shaft 9 o'"'"'clock image, a follow-through shaft 3 o'"'"'clock image, and a finish image as check-point images.

7. The golf swing diagnosis system according to claim 1, wherein said operation extraction means executes background subtraction of said still image by using a background image in which a golfer is not photographed to obtain a golfer'"'"'s silhouette;

extracts a contour of said silhouette;

regards a pixel which makes a curvature of said contour extreme as an unskillful arm side shoulder;

computes a position of a grip from a positional relationship between two of said colored marks;

stores at least one part of said still image in a range from said shoulder at said unskillful arm side to said grip as a template; and

extracts a movement of a golfer'"'"'s unskillful arm by executing template matching processing for a still image during a take-back swing; and

said image extraction means regards a frame of said still image in which said template has become horizontal as an image in which said unskillful arm is horizontal in said take-back swing, based on data obtained by said operation extraction means, thus extracting said still image as a check-point image.

8. The golf swing diagnosis system according to claim 7, wherein said image extraction means stores at least one part of said images in said range from said shoulder to said grip in said still image in which said unskillful arm is horizontal in said take-back swing as a template;

and executes template matching processing for said still image in a downswing and regards a frame of an image that matches said template to a highest extent as said still image in which said unskillful arm is horizontal in said downswing, thus extracting said image that matches said template to the highest extent as a check-point image.

9. The golf swing diagnosis system according to claim 1, wherein said image extraction means executes differential processing for said still image by using a background image in which a golfer is not photographed to obtain said golfer'"'"'s silhouette and obtain one end of said silhouette as a soklutan of a golfer'"'"'s leg at the skillful arm side from a left-to-right width of said silhouette;

and regards an image at a time when a perpendicular passing through said side of said leg at the skillful arm side intersects with said colored mark attached to said shaft as a take-back shaft 8 o'"'"'clock image, thus extracting said take-back shaft 8 o'"'"'clock image as a check-point image.

10. The golf swing diagnosis system according to claim 1, wherein said image extraction means regards a photographed first swing image as an address image or regards a still image in which a differential is minimum when differential processing is executed between frames from a start time of an extraction of said swing images as said address image, thus extracting said address image as a check-point image.

13. The golf swing diagnosis system according to claim 1, wherein when recognition of said colored marks has failed in executing binarization for pixels of each of said still images by using a specific threshold of color information,

of a plurality of said still images constructing said color moving image, differential processing is executed between a pair of still images spaced at a certain time interval so as to regard one of said still images in which the number of pixels whose norm is larger than a predetermined threshold becomes a minimum value as a top image and extract said top image as a check-point image.

14. The golf swing diagnosis system according to claim 1, wherein when recognition of said colored marks has failed, an extraction of a downswing shaft 9 o'"'"'clock image has failed, and an extraction of a take-back shaft 9 o'"'"'clock image has succeeded in executing binarization for pixels of each of said still images by using a specific threshold of color information,

a search range is set on said still image by setting a coordinate of a position of each of said colored marks in said take-back shaft 9 o'"'"'clock image as a reference, and an allowable color range regarded as the same color as that of each of said colored marks is set on said still image;

a pixel falling in said color range is regarded as a position of each of said colored marks in said search range so as to recognize said coordinate of said position of each of said colored marks in said take-back shaft 9 o'"'"'clock image; and

an image in which a vector between two or more of said colored marks is most horizontal is regarded as said downswing shaft 9 o'"'"'clock image so as to extract said downswing shaft 9 o'"'"'clock image as a check-point image.

15. The golf swing diagnosis system according to claim 1, wherein a search range having a predetermined area is set on a periphery of a ball in a still image;

and differential processing is executed between a pair of still images spaced at a certain time interval so as to regard a still image at a time when the number of pixels whose norm value is larger than a predetermined threshold starts to increase or at a time when the number of said pixels whose norm value is larger than said predetermined threshold exceeds another threshold as an impact image so as to extract said impact image as a check-point image.

16. The golf swing diagnosis system according to claim 1, wherein a detection sensor that detects a passage of a golf club is provided in the vicinity of a ball so that based on a trigger signal outputted from said detection sensor, an impact image is extracted from a plurality of said still images.

17. The golf swing diagnosis system according to claim 1, wherein a sound collection means connected with a computer is provided so that based on a sound generated when said golf club hits a ball, an impact image is extracted from a plurality of said still images.

18. The golf swing diagnosis system according to claim 1, wherein an allowable range of a color regarded as the same color as that of a golfer'"'"'s skin is set;

a skin extraction is executed by regarding a pixel falling in said color range of said pixel-color information in a plurality of said still images as a golfer'"'"'s skin-color range; and

binarization is not executed for said skin-color range in an assumption that said colored marks are not present in said skin-color range.

11. A golf swing diagnosis system comprising a computer for capturing a colored moving image obtained by photographing a golfer who swings by gripping a golf club having colored marks attached to a shaft thereof,

wherein said computer comprises:

a means for converting said colored moving image into a plurality of still images;

a means for executing binarization for each pixel of a plurality of said still images by using a specific threshold of color information and recognizing pixels, of said still images, which satisfy said threshold as positions of said colored marks so as to obtain coordinate data of each of said colored marks;

an operation extraction means for executing differential processing of said still image by using a background image in which a golfer is not photographed to obtain a golfer'"'"'s silhouette;

extracting a contour of said silhouette;

regarding a pixel which makes a curvature of said contour extreme as an unskillful arm side shoulder;

computing a position of said grip from a positional relationship between two of said colored marks;

storing at least one part of images in a range from said shoulder at said unskillful arm side to said grip as a template; and

extracting a movement of a golfer'"'"'s unskillful arm by executing template matching processing for a still image during a take-back swing; and

an image extraction means for regarding a frame of said still image in which said template has become horizontal as an image in which said unskillful arm is horizontal in said take-back swing, based on data obtained by said operation extraction means, thus extracting said still image as a check-point image.

12. The golf swing diagnosis system according to claim 11, wherein said image extraction means stores at least one part of said images in said range from said shoulder to said grip in said still image in which said unskillful arm is horizontal in said take-back swing as a template;

and executes template matching processing for said still image in a downswing and regards a frame of an image that matches said template to a highest extent as said still image in which said unskillful arm is horizontal in said downswing, thus extracting said image that matches said template to the highest extent as a check-point image.

19. A golf swing diagnosis system comprising a computer for capturing a colored moving image obtained by photographing a golfer who swings by gripping a golf club having colored marks attached to a shaft thereof,

said computer comprising:

a means for converting said colored moving image into a plurality of still images;

an image extraction means for executing differential processing for said still image by using a background image in which a golfer is not photographed to obtain said golfer'"'"'s silhouette and obtain one end of said silhouette as a soklutan of a golfer'"'"'s leg at the skillful arm side from a left-to-right width of said silhouette; and

regarding an image at a time when a perpendicular passing through said side of said leg at the skillful arm side intersects with said colored mark attached to said shaft as a take-back shaft 8 o'"'"'clock image, thus extracting said take-back shaft 8 o'"'"'clock image as a check-point image; and

an output means for outputting said extracted still image.

20. A golf swing diagnosis system comprising a computer for capturing a colored moving image obtained by photographing a golfer who swings by gripping a golf club having colored marks attached to a shaft thereof,

said computer comprising:

a means for converting said colored moving image into a plurality of still images;

an image extraction means for regarding a photographed first swing image as an address image or regarding a still image in which a differential is minimum when differential processing is executed between frames from a start time of an extraction of said swing images as said address image, thus extracting said take-back shaft 8 o'"'"'clock image as a check-point image; and

an output means for outputting said extracted still image.