Method and system for determining ping-pong ball drop point data in video images

Abstract

The invention discloses a method and system for determining ping-pong ball drop point data in video images. The method comprises the steps that an image which is collected under high resolution is used for camera calibration, and the corresponding relation between a camera plane and a plane where a ping-pong table is placed is acquired to form a first homography matrix; table tennis competition images under low resolution are collected in real time, and the image coordinates of a ping-pong ball in the competition images are calculated in real time; the image coordinates of drop points of the ping-pong ball are determined from the image coordinates of the ping-pong ball in the competition images; the first homography matrix is converted into a second homography matrix; and the physical coordinates of the drop points of the ping-pong ball are calculated according to the second homography matrix and the image coordinates of the drop points of the ping-pong ball. The method and system for determining the ping-pong ball drop point data in the video images lower the cost, improve the precision of measuring of the drop points of the ping-pong ball, and are more suitable for television relaying of table tennis competitions.

Description

Technical field [0001] The present invention relates to the technical field of image processing, in particular to a method for determining table tennis drop data in a video image, and a system for determining table tennis drop data in a video image. Background technique [0002] The drop point is one of the five elements of table tennis (speed, strength, drop point, arc, and rotation). The change and control of the drop point reflects the strain and control ability of table tennis players, and is a concrete manifestation of accuracy; at the same time, The ability to control the drop point directly affects the quality of line changes, thereby affecting the quality of technology and tactics. [0003] However, for a long time, as one of the key techniques and tactics to win, the training and assessment of the "drop point and the ability to control the drop point" has always stayed at the qualitative stage. This qualitative training has not kept up with the current development of table...

AI Technical Summary

Problems solved by technology

Hawkeye technology is an instant playback system, which is composed of 8 or 10 high-speed cameras, four computers and a large screen. The high-speed cameras are used to simultaneously capture the basic data of the ball's flight trajectory from different angles, and these data are generated into three-dimensional images through computer calculation. , and finally the ball's movement route and landing point are displayed on the large screen. Due to the high price and large number of these hardware devices, the cost is relatively high. Moreover, the installed camera must not be blocked by the athlete's body when capturing the basic data of the ball's flight trajectory. , resulting in complex construction, so Hawkeye technology has not yet been applied to table tennis matches

[0005] The pressure sensing technology realizes the measurement of the drop point of the table tennis ball by installing a pressure sensor under the table tennis table top, and can only measure a single table tennis drop point information. The structure of the standard table tennis table does not conform to the rules for the use of table tennis tables in official competitions. It is difficult to apply it to official competitions, so it is impossible to obtain the information of the table tennis balls in the TV broadcast.

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