https://www.it610.com/article/5477845.htm
目标：
目录/home/camera 中保存了2000张照相机连续拍照的JPG文件，名字按数字排序 1.jpg 2.jpg 3.jpg ......... 现在需要在ROS中建立一个node按频率发布所有照片，并可以在image_view中看视频效果。 详细见链接：http://wiki.ros.org/image_transport/Tutorials/PublishingImages首先安装image_transport,一般在安装ROS时都安装过了。执行
sudo apt-get install ros-indigo-image-transport
发布node的代码：
#include <ros/ros.h> #include <stdlib.h> #include <image_transport/image_transport.h> #include <opencv2/highgui/highgui.hpp> #include <cv_bridge/cv_bridge.h>
int main(int argc, char** argv) { ros::init(argc, argv, “image_publisher”); ros::NodeHandle nh; image_transport::ImageTransport it(nh); image_transport::Publisher pub = it.advertise(“camera/image”, 1);
ros::Rate loop_rate(5); for(int i = 0; i < 2000; i++) { if(!nh.ok()) break; std::ostringstream stringStream; stringStream << “/home/camero/” << i << “.jpg”; cv::Mat image = cv::imread(stringStream.str(), CV_LOAD_IMAGE_COLOR); sensor_msgs::ImagePtr msg = cv_bridge::CvImage(std_msgs::Header(), “bgr8”, image).toImageMsg();
pub.publish(msg); ros::spinOnce(); loop_rate.sleep();} }
使用image_view 查看视频流
上面的node发布视频流到 /camera/image 上，但是image_transport同时还发布了其它的topic用来兼容image_view的功能，就是说上面的代码自动帮助发布了有压缩格式的视频流：
/camera/image /camera/image/compressed /camera/image/compressed/parameter_descriptions /camera/image/compressed/parameter_updates /camera/image/compressedDepth /camera/image/compressedDepth/parameter_descriptions /camera/image/compressedDepth/parameter_updates /camera/image/theora /camera/image/theora/parameter_descriptions /camera/image/theora/parameter_updates
使用下面的命令查看图片流效果：
rosrun image_view image_view image:=/camera/image
如果要查看压缩视频流效果，需要增加一个参数就可以了：
rosrun image_view image_view image:=/camera/image/ image_transport:=‘compressed’
