Hi all -
I'm trying to use TimeSynchronizer to sync up images from two cameras,
but I'm having some problems. In the following lines:
message_filters::Subscriber<Image> left_sub(nh,
"stereo/left/image", 1);
message_filters::Subscriber<Image> right_sub(nh,
"stereo/right/image", 1);
TimeSynchronizer<Image, Image> sync(left_sub, right_sub, 10);
sync.registerCallback(boost::bind(&callback, _1, _2));
in the callback, both left and right appear to be the same image (they
both seem to come from the rightmost subscriber given to sync). I've
checked stereo/left/image and stereo/right/image with image_view and
they are definitely different. Is there something I'm missing here? Code
to reproduce is attached.
On a related note, is there a way to use TimeSynchronizer with
image_transport rather than subscribing to the image directly?
Thanks,
-Dan
#include <ros/ros.h>
#include <image_transport/image_transport.h>
#include <cv_bridge/CvBridge.h>
#include <opencv/cv.h>
#include <opencv/highgui.h>
#include <message_filters/subscriber.h>
#include <message_filters/time_synchronizer.h>
#include <sensor_msgs/Image.h>
using namespace message_filters;
using namespace sensor_msgs;
sensor_msgs::CvBridge bridge;
void callback(const ImageConstPtr& left, const ImageConstPtr& right) {
IplImage* im_left = bridge.imgMsgToCv(left, "rgb8");
IplImage* im_right = bridge.imgMsgToCv(right, "rgb8");
cvShowImage("left", im_left);
cvShowImage("right", im_right);
}
int main(int argc, char **argv) {
ros::init(argc, argv, "sync_node");
ros::NodeHandle nh;
cvNamedWindow("left");
cvNamedWindow("right");
cvStartWindowThread();
message_filters::Subscriber<Image> left_sub(nh, "stereo/left/image", 1);
message_filters::Subscriber<Image> right_sub(nh, "stereo/right/image", 1);
TimeSynchronizer<Image, Image> sync(left_sub, right_sub, 10);
sync.registerCallback(boost::bind(&callback, _1, _2));
ros::spin();
return 0;
}