Automatically compress and decompress ROS messages. Usefull to subscribe to large messages over Wifi.

Do you have problem with large messages, such as PointCloud2 or OccupancyGrid when you connect to a remote robot using Wifi? This package is for you.

Let's suppose that you want to compress a message of type PointCloud2 and named /velodyne_points.

• Run topic_compress_server on the robot, or the PC where the large messages are being published.

  rosrun topic_compressor topic_compress_server
  

• On the other PC (the subscriber side) run:

  rosrun topic_compressor topic_compress_client _topics:=/velodyne_points
  

• Note that you can ask pass to the client multiple, comma separated, names of topics.

For each of the specified topics:

1. The server will compress the messages and publish a compressed version of it, with the suffix "/compressed". In this case /velodyne_points/compressed

2. The client will publish /velodyne_points/decompressed

3. Only if another ROS Node is subscribed to /velodyne_points/decompressed, the communication between the server and the client take place. in other words, if no one use the decompressed message, no CPU not network bandwidth is wasted.