Video Overlay Tool

Overview

Inputs:

• ROS bag file with several vehicles' trajectories (on /<veh_name>/pose topics)
• video from a stationary camera
• homography matrix btwn camera plane and planar vehicle pose frame

Outputs:

• video with trajectories overlayed on the stationary camera's stream

Instructions

Clone the repo, catkin_make, then:

roslaunch video_overlay video_overlay_node.launch experiment:=4_hexes_parallel_swaps_1_pass

Set/update the args in video_overlay_node.launch to point to the correct yaml files (homography, experiment)

If you don't have a homography matrix already, you should:

• find a recognizable moment in your video & take a screenshot
• find the corresponding vicon coordinates during that moment (from the bag)
• Click on the corresponding vehicle positions in the screenshot, using:

rosrun video_overlay video_overlay_node <screenshot_filename>

• Create a new .yaml file in config/homography_pts with the vicon and img coords
• Switch which .yaml file is loaded in the launch file
• Your homography matrix will be computed for you at the start of the script

The outcpp.avi file will be giant. You can compress it with ffmpeg (increase -crf to make file smaller):

ffmpeg -i outcpp.avi -crf 25 outcpp_small.avi

Contact: mfe@mit.edu