KITTI to ROS2 Bag Converter

A ROS 2 package to create ROS 2 bag files from the KITTI datasets. It uses KITTI Odometry for ground-truth poses, Velodyne point clouds, and camera images, and optionally integrates KITTI Raw to include IMU and GPS. If no KITTI Raw directory is provided, only odometry-derived data (odometry, TF, path, point clouds, cameras, camera info) are recorded.

Available Topics

All bags include these topics:

Topic	Message Type	Description
/kitti/velo/pointcloud	sensor_msgs/msg/PointCloud2	Velodyne LiDAR point clouds
/kitti/gtruth/odom	nav_msgs/msg/Odometry	Ground-truth odometry poses
/kitti/gtruth/path	nav_msgs/msg/Path	Accumulated ground-truth trajectory
/kitti/camera_gray_left/image	sensor_msgs/msg/Image	Grayscale left camera
/kitti/camera_gray_right/image	sensor_msgs/msg/Image	Grayscale right camera
/kitti/camera_color_left/image	sensor_msgs/msg/Image	Color left camera
/kitti/camera_color_right/image	sensor_msgs/msg/Image	Color right camera
/kitti/camera_gray_left/camera_info	sensor_msgs/msg/CameraInfo	Grayscale left calibration
/kitti/camera_gray_right/camera_info	sensor_msgs/msg/CameraInfo	Grayscale right calibration
/kitti/camera_color_left/camera_info	sensor_msgs/msg/CameraInfo	Color left calibration
/kitti/camera_color_right/camera_info	sensor_msgs/msg/CameraInfo	Color right calibration
/tf	tf2_msgs/msg/TFMessage	Dynamic transforms (odom → base_link)
/tf_static	tf2_msgs/msg/TFMessage	Static transforms (map/odom/sensors)

If KITTI Raw is provided and supported for the sequence, these are added:

Topic	Message Type	Description
/kitti/oxts/imu	sensor_msgs/msg/Imu	IMU data from OXTS
/kitti/oxts/gps	sensor_msgs/msg/NavSatFix	GPS fix from OXTS

Prerequisites

• Operating System: Ubuntu 20.04+ (tested on Ubuntu 24.04)
• ROS 2 Distribution: Humble, Iron, or Jazzy
• Python: 3.8+
• Dependencies:
  • pykitti for KITTI dataset handling
  • opencv-python for image processing
  • numpy, scipy for numerical computations

Tested Platforms

• Ubuntu 24.04
• ROS 2 Kilted
• Python 3.12+

Installation

1. Clone the Repository

cd ~/ros2_ws/src
git clone https://github.com/distancetech/kitti_to_ros2bag.git

2. Install Python Dependencies

pip3 install pykitti opencv-python numpy scipy tf-transformations

3. Build the Package

cd ~/ros2_ws
source /opt/ros/<your-ros-distro>/setup.bash
colcon build --packages-select kitti_to_ros2bag --symlink-install
source install/setup.bash

Usage

Dataset Preparation

• KITTI Odometry is required
• KITTI Raw is optional (only if you want IMU/GPS); mapping is automatic for supported sequences

1. KITTI Odometry Dataset

Download from the KITTI Odometry Benchmark (poses and velodyne). Directory structure:

~/kitti_data/dataset/
├── poses/
│   ├── 00.txt
│   ├── 01.txt
│   └── ...
└── sequences/
    ├── 00/
    │   ├── calib.txt
    │   ├── image_0/  (for images if available)
    │   ├── image_1/
    │   ├── image_2/
    │   ├── image_3/
    │   └── velodyne/
    └── ...

2. KITTI Raw Dataset (optional, for IMU/GPS)

Place extracted drives under a root such as ~/kitti_raw_data/2011_10_03/2011_10_03_drive_0027_sync/.

Launch Arguments

• odometry_dir (required): Path to KITTI odometry root containing sequences/ and poses/.
• raw_dir (optional): Path to KITTI Raw root (date folders). If provided, IMU/GPS will be included when available for the sequence.
• sequence (required): KITTI sequence string (e.g., 00, 01, ...).
• bag_dir (optional): Output rosbag directory. Default is ./odom_bag_XX where XX is the sequence.

Running the Converter

• Odometry only:

cd ~/ros2_ws
source install/setup.bash
ros2 launch kitti_to_ros2bag kitti_odometry_bag.launch.py \
  odometry_dir:=/absolute/path/to/kitti_odometry \
  sequence:=02

• Odometry + Raw (adds IMU/GPS) and custom output path:

cd ~/ros2_ws
source install/setup.bash
ros2 launch kitti_to_ros2bag kitti_odometry_bag.launch.py \
  odometry_dir:=/absolute/path/to/kitti_odometry \
  raw_dir:=/absolute/path/to/kitti_raw \
  sequence:=02 \
  bag_dir:=/absolute/path/to/output/my_bag

Verification

ros2 bag info /absolute/path/to/output/my_bag

Playing ROS 2 Bags

To play with proper QoS settings:

ros2 bag play /absolute/path/to/output/my_bag

Example Subscriber Nodes

#!/usr/bin/env python3

import rclpy
from rclpy.node import Node
from sensor_msgs.msg import Imu

class KittiImuSubscriber(Node):
    def __init__(self):
        super().__init__('kitti_imu_subscriber')
        self.subscription = self.create_subscription(Imu, '/kitti/oxts/imu', self.imu_callback, 10)
        self.get_logger().info('KITTI IMU subscriber started')

    def imu_callback(self, msg):
        self.get_logger().info(f'IMU accel x: {msg.linear_acceleration.x:.3f}')

def main():
    rclpy.init()
    node = KittiImuSubscriber()
    try:
        rclpy.spin(node)
    except KeyboardInterrupt:
        pass
    finally:
        node.destroy_node()
        rclpy.shutdown()

if __name__ == '__main__':
    main()

#!/usr/bin/env python3

import rclpy
from rclpy.node import Node
from sensor_msgs.msg import PointCloud2

class KittiPointCloudSubscriber(Node):
    def __init__(self):
        super().__init__('kitti_pointcloud_subscriber')
        self.subscription = self.create_subscription(PointCloud2, '/kitti/velo/pointcloud', self.cb, 10)

    def cb(self, msg):
        self.get_logger().info(f'PointCloud2: width={msg.width}, fields={[f.name for f in msg.fields]}')

def main():
    rclpy.init()
    node = KittiPointCloudSubscriber()
    try:
        rclpy.spin(node)
    except KeyboardInterrupt:
        pass
    finally:
        node.destroy_node()
        rclpy.shutdown()

if __name__ == '__main__':
    main()

#!/usr/bin/env python3

import rclpy
from rclpy.node import Node
from nav_msgs.msg import Odometry

class KittiOdometrySubscriber(Node):
    def __init__(self):
        super().__init__('kitti_odometry_subscriber')
        self.subscription = self.create_subscription(Odometry, '/kitti/gtruth/odom', self.cb, 10)

    def cb(self, msg):
        p = msg.pose.pose.position
        self.get_logger().info(f'Position: [{p.x:.2f}, {p.y:.2f}, {p.z:.2f}]')

def main():
    rclpy.init()
    node = KittiOdometrySubscriber()
    try:
        rclpy.spin(node)
    except KeyboardInterrupt:
        pass
    finally:
        node.destroy_node()
        rclpy.shutdown()

if __name__ == '__main__':
    main()

Contributing

Contributions are welcome! Please feel free to submit a Pull Request. For major changes, please open an issue first to discuss what you would like to change.

License

This project is licensed under the Apache License 2.0 - see the LICENSE file for details.

Support

If you find this package useful, please consider starring the repository. For issues and feature requests, please use the GitHub issue tracker.