Running rtabmap on ROS2 with zed camera data in rosbag

[tapan]

Need help in finding resources to run rtabmap on ROS2 with zed camera data in rosbag

[dave]

Hi tapan,

You should be able to find the resources on the GitHub page of the repository, there is an example inside the rtabmap_launch directory: https://github.com/introlab/rtabmap_ros/tree/ros2/rtabmap_launch

The example is as follows:

```
ros2 launch rtabmap_launch rtabmap.launch.py \
    rtabmap_args:="--delete_db_on_start" \
    rgb_topic:=/zed/zed_node/rgb/image_rect_color \
    depth_topic:=/zed/zed_node/depth/depth_registered \
    camera_info_topic:=/zed/zed_node/rgb/camera_info \
    frame_id:=zed_camera_link \
    approx_sync:=false \
    wait_imu_to_init:=true \
    imu_topic:=/zed/zed_node/imu/data \
    rviz:=true
```
In the example above, it assumes you use the depth module of the ZED camera.

If you want to use the ZED camera as a stereo camera, you can use the following, like me (I use the ZED2 camera):

"""
ros2 launch rtabmap_launch rtabmap.launch.py \
    stereo:=true \
    use_sim_time:=true \
    frame_id:=zed2_left_camera_frame \
    args:="--delete_db_on_start" \
    left_image_topic:=/zed2/zed_node/left/image_rect_color \
    right_image_topic:=/zed2/zed_node/right/image_rect_color \
    left_camera_info_topic:=/zed2/zed_node/left/camera_info \
    right_camera_info_topic:=/zed2/zed_node/right/camera_info
"""

Note that, as you want to use a rosbag, you might want to set the parameter `use_sim_time:=true` so rtabmap can use the time from the rosbag instead of the system time.

Let me know if you have more questions.

With kind regards,
Dave