View source for Foxy Image subscriber experiment pro.cpp

<pre>
// Image Subscriber Demo - procedural version
//
// Based on Adding Video Capture in ROS 2
// https://www.stereolabs.com/docs/ros2/video/
//
// Ed C. Epp


#include <memory>
#include "rclcpp/rclcpp.hpp"
#include "sensor_msgs/msg/image.hpp"

// Declare the node pointer
rclcpp::Node::SharedPtr g_node = nullptr;

// ---------------------------------------------------------------------
// Create the image callback function
void image_callback(const sensor_msgs::msg::Image::SharedPtr msg)
{
  RCLCPP_INFO(g_node->get_logger(), "I See: " + msg->encoding);
}

// --------------------------------------------------------------------
// main
int main(int argc, char* argv[])
{
  // Act on the parameters and other stuff
  rclcpp::init(argc, argv);

  // Create the ROS node
  g_node = rclcpp::Node::make_shared("Image_Subscriber_Pro_Test");

  // Set the quality of service
  rclcpp::QoS video_qos(10);
  video_qos.keep_last(10);
  video_qos.best_effort();
  video_qos.durability_volatile();  

  // Subscribe to image topics
  auto subscription_ = g_node->create_subscription<sensor_msgs::msg::Image>(
       "image", video_qos, image_callback);
  RCLCPP_INFO(g_node->get_logger(), "Image subscriber created");

  // Start the node up
  rclcpp::spin(g_node);
  
  rclcpp::shutdown();
  return 0;
}
</pre>