基于topic通信的图像/视频传输(C++)

构建ROS pkg

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cd catkin_ws/src
catkin_create_pkg vid roscpp rospy std_msgs

cpp编写

头文件引用

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#include<ros/ros.h>
#include "sensor_msgs/Image.h"
#include "sensor_msgs/CompressedImage.h"
#include "sensor_msgs/image_encodings.h"
#include <image_transport/image_transport.h>
#include <cv_bridge/cv_bridge.h>
#include <opencv2/opencv.hpp>

回调函数

我们使用ROS的图像话题格式：sensor_msgs::ImageConstPtr、sensor_msgs::CompressedImageConstPtr(压缩后)作为msg格式

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void vidCallback(const sensor_msgs::CompressedImageConstPtr& msg)
{
    cv::Mat cv_ptr;//
    try
    {
        //转换:CompressedImageConstPtr转为ImageConstPtr
        cv_bridge::CvImagePtr cv_ptr_compressed = cv_bridge::toCvCopy(msg,sensor_msgs::image_encodings::BGR8);
        //转换:ImageConstPtr转为cv::Mat
        cv_ptr = cv_ptr_compressed->image;
        //显示帧
        cv::imshow("imgCallback",cv_ptr);
        cv::waitKey(1);
        ROS_INFO("loading...");//输出信息
    }
    catch (cv_bridge::Exception& e)
    {
        //格式错误的处理
    }
}

主函数

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int main(int argc, char** argv){
    ros::init(argc,argv,"listener");
    ros::NodeHandle n;//句柄
    
    //订阅话题、消息队列长度、回调函数
    ros::Subscriber sub = n.subscribe("话题名字",1,vidCallback);
    ros::spin();//循环
    return 0;
}

编译

CMakeLists更改

cmake不太会，先赶出来一版能用的顶上去，暂时没有bug

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find_package(catkin REQUIRED COMPONENTS
  roscpp
  rospy
  std_msgs
  sensor_msgs
  cv_bridge
  image_transport
  OpenCV
)
include_directories(${OpenCV_INCLUDE_DIRS})
link_directories(${OpenCV_LIBRARY_DIRS})
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add_executable(vidDemo src/test.cpp)
target_link_libraries(vidDemo
   ${catkin_LIBRARIES}
   ${OpenCV_LIBRARIES}
 )

执行编译

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catkin_make