Program Listing for File image_view_node.hpp
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// Copyright 2015 Open Source Robotics Foundation, Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#ifndef IMAGE_PIPELINE__IMAGE_VIEW_NODE_HPP_
#define IMAGE_PIPELINE__IMAGE_VIEW_NODE_HPP_
#include <sstream>
#include <string>
#include "opencv2/highgui/highgui.hpp"
#include "rclcpp/rclcpp.hpp"
#include "sensor_msgs/msg/image.hpp"
#include "common.hpp"
class ImageViewNode final : public rclcpp::Node
{
public:
explicit ImageViewNode(
const std::string & input, const std::string & node_name = "image_view_node",
bool watermark = true)
: Node(node_name, rclcpp::NodeOptions().use_intra_process_comms(true))
{
// Create a subscription on the input topic.
sub_ = this->create_subscription<sensor_msgs::msg::Image>(
input,
rclcpp::SensorDataQoS(),
[node_name, watermark](sensor_msgs::msg::Image::ConstSharedPtr msg) {
// Create a cv::Mat from the image message (without copying).
cv::Mat cv_mat(
msg->height, msg->width,
encoding2mat_type(msg->encoding),
const_cast<unsigned char *>(msg->data.data()));
if (watermark) {
// Annotate with the pid and pointer address.
std::stringstream ss;
ss << "pid: " << GETPID() << ", ptr: " << msg.get();
draw_on_image(cv_mat, ss.str(), 60);
}
// Show the image.
cv::Mat c_mat = cv_mat;
cv::imshow(node_name.c_str(), c_mat);
char key = cv::waitKey(1); // Look for key presses.
if (key == 27 /* ESC */ || key == 'q') {
rclcpp::shutdown();
}
if (key == ' ') { // If <space> then pause until another <space>.
key = '\0';
while (key != ' ') {
key = cv::waitKey(1);
if (key == 27 /* ESC */ || key == 'q') {
rclcpp::shutdown();
}
if (!rclcpp::ok()) {
break;
}
}
}
});
}
private:
rclcpp::Subscription<sensor_msgs::msg::Image>::SharedPtr sub_;
cv::VideoCapture cap_;
cv::Mat frame_;
};
#endif // IMAGE_PIPELINE__IMAGE_VIEW_NODE_HPP_