Detection of Mitt Movement Trajectory in Catcher Framing Using Baseball Video

The technique of catcher framing in baseball, which is performed when catching a pitch near the border of the strike zone, has recently attracted research attention. In this technique, the catcher moves their catcher’s mitt and body slightly to increase the likelihood that the umpire determines a pitch as a strike. In this paper, we propose a method to detect the mitt movement trajectory in catcher framing. In our proposed method, using videos of baseball games, we detected the position at which the catcher catches a pitch (catch position) and stops their catcher’s mitt (mitt stop position). We also detected the mitt movement trajectory by connecting the catch position and the mitt stop position. At that point, we considered the strike zone based on an estimation of the pose of the batter. We performed experiments wherein we verified the detection of the batter, catch position, and mitt stop position. As a result, we confirmed that our proposed strike zone and mitt movement trajectory detection methods are highly accurate.