Camera Publisher Package

A ROS2 package for publishing camera streams with support for multiple cameras and UITM topics.

Setup Instructions

1. Clone the Repository

cd ~/ros2_ws/src
git clone https://github.com/HelloWorldRobotics/camera_publisher.git

2. Install Dependencies

Install all required dependencies using rosdep:

cd ~/ros2_ws
rosdep install --from-paths src --ignore-src -r -y

3. UDEV Rules Setup (Optional)

To ensure consistent camera device naming, it is convenient to set up UDEV rules for each camera.

Create a new UDEV rules file:

sudo nano /etc/udev/rules.d/99-usb-cameras.rules

To find the correct UDEV rule for each camera:

1. Unplug all USB cameras
2. Plug in one camera at a time
3. Note the new /dev/video* device that appears
4. Run this command to get the camera's ID_PATH:

udevadm info -q property -p $(udevadm info -q path -n /dev/video0) | grep ID_PATH

5. Create a UDEV rule using this format:

SUBSYSTEM=="video4linux", ENV{ID_PATH}=="pci-0000:03:00.0-usb-0:1.1:1.0", KERNEL=="video*", SYMLINK+="buggy_cam_back"

6. Repeat for each camera, using appropriate symlinks:
   • buggy_cam_front
   • buggy_cam_back
   • buggy_cam_left
   • buggy_cam_right

Apply the new rules:

sudo udevadm control --reload-rules
sudo udevadm trigger

4. Launch File Configuration

The launch file (camera_publisher.launch.py) supports multiple cameras with configurable parameters. If udev rules are not used, the camera device paths must be updated in the launch file. To disable launching a camera, simply comment out the corresponding camera in the return LaunchDescription. Eg:

return LaunchDescription([
    back_camera,
    left_camera,
    right_camera,
    #front_camera
])

Parameters Description

Parameter	Type	Description
frame_id	string	TF frame ID for the camera
parent_frame_id	string	Parent TF frame ID
camera_device	string	Camera device path (e.g., /dev/buggy_cam_back)
calibration_file	string	Path to camera calibration YAML file
flip_image	bool	Whether to flip the image 180 degrees
publish_compressed	bool	Enable compressed image publishing
uitm_topics	bool	Enable UITM topic publishing
uitm_calibration_file	string	Path to UITM calibration YAML file

Main Output Topics

Topic	Type	Description
~/image/raw	sensor_msgs/Image	Raw camera image (1280x720)
~/image/compressed	sensor_msgs/CompressedImage	JPEG compressed image
~/camera_info	sensor_msgs/CameraInfo	Camera calibration information

UITM Output Topics (if enabled)

Topic	Type	Description
~/uitm/image/raw	sensor_msgs/Image	Raw UITM image (640x480)
~/uitm/image/compressed	sensor_msgs/CompressedImage	JPEG compressed UITM image
~/uitm/camera_info	sensor_msgs/CameraInfo	UITM camera calibration info

Configuration Files

Place your camera calibration files in:

• Main calibration: config/*.yaml
• UITM calibration: config/uitm/*.yaml

Building and Running

Build with symlink:

cd ~/ros2_ws
colcon build --symlink-install --packages-select camera_publisher

Source workspace:

source ~/ros2_ws/install/setup.bash

Run the publisher:

ros2 launch camera_publisher camera_publisher.launch.py