cam_publisher

Overview

The cam_publisher package is a ROS node developed to capture images from a camera and publish them on a ROS topic. It uses OpenCV for image capture and cv_bridge to convert OpenCV images to ROS messages. The camera calibration parameters are loaded from a YAML file.

Keywords: ROS, OpenCV, Camera, Image Publisher

Building from Source

Dependencies

• Robot Operating System (ROS)
• OpenCV
• YAML-CPP

sudo rosdep install --from-paths src

Config Files

Camera Configuration

Camera configuration files, such as (config/front_camera.yaml):

image_width: 1920
image_height: 1080
camera_matrix:
  rows: 3
  cols: 3
  data: [1332.2905012603742, 0.0, 1001.619419558725, 0.0, 1313.963171950812, 491.9312293181554, 0.0, 0.0, 1.0]
distortion_model: plumb_bob
distortion_coefficients:
  rows: 1
  cols: 5
  data: [-0.5176939966889225, 0.17338115766870202, 0.023434654253362403, -0.008230427613718875, 0.0]
rectification_matrix:
  rows: 3
  cols: 3
  data: [1.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 1.0]
projection_matrix:
  rows: 3
  cols: 4
  data: [862.3757981998015, 0.0, 958.1924244615784, 0.0, 0.0, 1187.5335378689128, 503.67812178921946, 0.0, 0.0, 0.0, 1.0, 0.0]

Launch Files

Main Launch File

Main launch file (launch/cam_publisher.launch):

<launch>
  <node name="image_publisher" pkg="cam_publisher" type="camera_node" output="screen">
    <param name="camera_info_yaml" value="$(find cam_publisher)/config/front_camera.yaml"/>
    <param name="device" value="2"/>
    <param name="topic_name" value="camera"/>
  </node>
</launch>

Nodes

image_publisher

The image_publisher node reads images from a camera and publishes the images on a ROS topic.

Published Topics

• /camera/image (sensor_msgs/Image): Images captured by the camera.

Parameters

• camera_info_yaml (string): Path to the YAML file containing the camera calibration parameters.
• device (int): Camera device number.
• topic_name (string): Name of the topic where images will be published. Default: "camera".