Task3/line_follower/launch/snapshot_capture.launch

<launch>
  <!-- This launch file deliberately does not start usb_cam or open a camera. -->
  <arg name="config" default="$(find line_follower)/config/snapshot_capture.yaml"/>
  <arg name="image_topic" default="/usb_cam/image_raw"/>
  <arg name="save_root" default="$(find line_follower)/data"/>

  <node pkg="line_follower" type="snapshot_capture.py" name="line_snapshot_capture" output="screen">
    <rosparam command="load" file="$(arg config)"/>
    <param name="image_topic" value="$(arg image_topic)"/>
    <param name="save_root" value="$(arg save_root)"/>
  </node>
</launch>