Hello,
sorry if this is a basic question but I couldn't find anything in the wiki.
I would like to retrieve the current value of a topic from the callback of
another topic. How is this possible? In more detail I have:
public:
ImageConverter(ros::NodeHandle &n) : n_(n), it_(n_)
{
cvNamedWindow("Image window");
image_sub_ = it_.subscribe("/camera_sim/image_raw", 1,
&ImageConverter::imageCallback, this);
}
void imageCallback(const sensor_msgs::ImageConstPtr& msg_ptr)
{
// Image obtained from subscribed node and converted to IplImage
IplImage *img = NULL;
try {
img = bridge_.imgMsgToCv(msg_ptr, "bgr8"); // reads the image
// I WOULD LIKE TO READ THE VALUE OF ANOTHER TOPIC
(std_msgs::String) HERE
}
catch (sensor_msgs::CvBridgeException error) {
ROS_ERROR("error");
}
}
Many Thanks