ROS2 Bag to PCD Converter

This script extracts point clouds from a ROS 2 bag file and saves each point cloud as a .pcd file along with its timestamp.

Dependencies

To run this script, you need to have the following dependencies installed:

• Python 3.8 or higher
• rosbags
• open3d
• sensor_msgs

You can install these dependencies using pip:

pip3 install rosbags open3d

Usage

Command Line Arguments

• --bag: Path to the ROS 2 bag file folder which contains .db3 and metadata files.

• --topic: Point cloud topic name which message type is sensor_msgs/PointCloud2.

Example

python3 extract_pointclouds_with_timestamps.py --bag <folder_path_to_rosbag_file> --topic <pointcloud_topic_name>

Script Description

1. The script reads a ROS 2 bag file specified by the --bag argument.
2. It extracts point cloud messages from the topic specified by the --topic argument.
3. Each point cloud is saved as a .pcd file in the pointclouds directory.
4. Corresponding timestamps are saved in text files in the same directory.

Output Files

• Point cloud files: pointclouds/0.pcd, pointclouds/1.pcd, ...
• Timestamp files: pointclouds/timestamp_0.txt, pointclouds/timestamp_1.txt, ...

Example

python3 extract_pointclouds_with_timestamps.py --bag /path/to/ros2bag/file/folder/ --topic /pointcloud_topic_name

This command will create the pointclouds directory and save the extracted point clouds and timestamps in it.