Mark for club head measurement and image processing device

Abstract

A mark for club head measurement in use for measuring information about a state of a club head of a golf club and provided on the golf club includes a central portion formed with a pattern having a lightness lower than the periphery thereof and a peripheral portion formed with a pattern surrounding the periphery of the central portion and having a lightness higher than the central portion.

What is claimed is: 
     
         1 . A mark for club head measurement in use for measuring information about a state of a club head of a golf club, the mark being provided on the club head, the mark comprising:
 a central portion formed with a pattern having a lightness lower than a periphery thereof; and   a peripheral portion formed with a pattern surrounding the periphery of the central portion and having a lightness higher than the central portion.   
     
     
         2 . The mark for club head measurement as defined in  claim 1 , wherein
 the central portion is circular, and the peripheral portion has a doughnut shape, and   the peripheral portion has a width smaller than a radius of the central portion.   
     
     
         3 . The mark for club head measurement as defined in  claim 1 , wherein a maximum brightness value of the central portion is 32 or less, and a difference between the maximum brightness value and a minimum brightness value of the central portion is 15 or less. 
     
     
         4 . The mark for club head measurement as defined in  claim 1 , wherein two doughnut-shaped marks each including the central portion and the peripheral portion are arranged side by side and formed integrally. 
     
     
         5 . The mark for club head measurement as defined in  claim 1 , wherein the mark is a sticker on which glue is applied to enable the mark to be affixed to the club head. 
     
     
         6 . An image processing device comprising:
 a mark detector configured to acquire time-series photographic images in which a club head is photographed when a golf club having a club head with the mark for club head measurement as defined in  claim 1  is swung, and to detect the mark for club head measurement from each of the photographic images; and   a head information generator configured to generate information about a state of the club head, based on the mark for club head measurement detected by the mark detector.   
     
     
         7 . The image processing device as defined in  claim 6 , wherein when the number of the marks for club head measurement detected from a certain photographic image of the photographic images is larger than a preset number, the mark detector specifies the mark for club head measurement included in the certain photographic image, based on information on the mark for club head measurement in another photographic image in which the preset number of the marks for club head measurement are detected. 
     
     
         8 . The image processing device as defined in  claim 7 , wherein
 the head information generator generates a trajectory image representing a trajectory of the club head of the golf club and a group of a plurality of face images each representing a face of the club head during the swing, as the information about a state of the club head, and   the image processing device comprises a control unit configured to display the trajectory image and the group of face images.   
     
     
         9 . An image processing device comprising:
 an image generating unit configured to generate a trajectory image representing a trajectory of a club head of a golf club during a swing of the golf club and a group of a plurality of face images each representing a face of the club head during the swing; and   a control unit configured to display the trajectory image and the group of face images.   
     
     
         10 . The image processing device as defined in  claim 9 , wherein the image generating unit generates an image representing the face by a straight line, as each of the face images.