=====Filtering Lasercan =====
Sometimes, Laserscans contain odd values that need being filtered out.  

====Creating a laser filter plugin====
  * Create a plugin package: ''catkin_create_pkg range_filter_plugin roscpp pluginlib sensor_msgs filters''
  * [[http://wiki.ros.org/pluginlib/Tutorials/Writing%20and%20Using%20a%20Simple%20Plugin| Write a plugin]]
  * [[http://wiki.ros.org/filters/Tutorials/Implementing%20a%20simple%20filter| Implement a filter plugin]]

====Running a laser pipeline ====
If you choose existing filters and the node ''laser_filters'' :
  * As explained in [[http://wiki.ros.org/laser_filters#Laser_Filter_Nodes|ROS wiki]], one may create a launchfile and a config file to automate the process.
  * **Caution**: make sure that the node ''laser_filters'' reads from the right laser scan topic. The config  file may rename the topics as in the following example: <WRAP box 350px>''# in my_laser_filter.launch \\ <remap from="scan" to="base_scan" /> ''</WRAP>

Interesting filters:
  * LaserScanRangeFilter: <WRAP box 350px>''# in my_laser_config.yaml \\ scan_filter_chain: \\ - name: range\\
  type: LaserScanRangeFilter \\  params: \\    lower_threshold: 10\\ ''</WRAP>
    * [[https://github.com/ros-perception/laser_filters/blob/hydro-devel/include/laser_filters/range_filter.h|git]]
    * check the param values: ''rosparam get /laser_filter/scan_filter_chain''

Other methods: filters 
http://wiki.ros.org/laser_filters
http://wiki.ros.org/laser_filters/Tutorials
http://wiki.ros.org/laser_pipeline/Tutorials
http://wiki.ros.org/laser_pipeline/Tutorials/IntroductionToWorkingWithLaserScannerData