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“…not everything that counts can be counted”

Network Analysis

Coordinate Mapping

Postioning Playback

Heatmap

Coordinate Video

Tennis

Proof-of-concept.

Inspired by Jeff Sackmann's work on the Match Charting Project, this is an attempt to apply the coordinate mapping to a perspective video.

Use the circle on the overlay above to mark the postion of the court using a single poitn perspective. Clicking on the ball positions then tracks the x,y coordinates in sync with the video timeline.

CSV Coordinate data appears here:

time, x, y

Basic video controls include: Space bar to play and pause the video , and . to step forward and back shift+, and shift+. to step by 10 seconds ctrl+, and ctrl+. to step by 60 seconds

The page uses the Youtube API to load in video footage. A court is then overlaid onto the video. It has handles to allow it to be mapped to the exact layout in the video. Simple trigonometry is then used to convert the layout into a single point perspective. The perspective is then used to map any mouse clicks on the highlighted area into court coordinates. The coordinates are centered at the centre of the court, ie coordinates range from -50,-50 in the top left to 50, 50 in the bottom right.

Obviously, this is a work in progress and apart from making the keyboard controls more robust, the next step would be to add keyboard entry to flag the shots as per the Match Charting, directly exporting the data into a CSV format.

Improvements to the UI would allow the court overlay to be adjusted more broadly, eg mirror changes the x-position of corners, or allow the vertical lines to be dragged directly.

…not everything that can be counted counts, and not everything that counts can be counted. William Bruce Cameron