Visualizing Motion in Video
Lisa M. Brown, Susan Crayne
28th Applied Imagery Pattern Recognition Workshop: 3D Visualization for Data
Exploration and Decision Making, 2000.
In this paper, we present a visualization system and method for measuring, inspecting and analyzing motion in video. Starting from a simple motion video, the system creates a still images representation whihc we call a digital strobe photograph. Similar to visualization techniques used in conventional film photography to capture high-speed motion using strobe lamps or very fast shutters, and to capture lime-lapse motion where the shutter is left open, this methodology creates a single image showing the motion of one or a small number of objects over time. Based on digital background subtraction, we assume that the background is stationary or at most slowing changing and that the camera position is fixed. The method is capable of displaying the motion based on a parameter indicating the time step between successive movements. It can also overcome problmes of visualizing movement thatis obscured by previous movements. The method is used in an educational software tool for children to measure and analyze various motions. Examples are given using simple physical objects such as balls and pendulums, astronomical evenets such as the path of the stars around the north pole at night, or the different types of locomotion used by snakes.