What's the difference between message_filters and image_transport?
Hi
I am using ROS Fuerte. I need to subscribe to 2 streams from the Kinect (color and depth) and use these to get 3D features. I understand to get the 2D feature I can use OpenCv and then relate this to the depth.
I have come across the link //wiki.ros.org/cv_bridge/Tutorials/UsingCvBridgeToConvertBetweenROSImagesAndOpenCVImages which has
16 image_transport::Subscriber image_sub_; 17 image_transport::Publisher image_pub_;
....
23 image_pub_ = it_.advertise("out", 1); 24 image_sub_ = it_.subscribe("in", 1, &ImageConverter::imageCb, this);
and the link
//wiki.ros.org/message_filters which has
19 message_filters::Subscriber<image> image1_sub(nh, "image1", 1); 20 message_filters::Subscriber<image> image2_sub(nh, "image2", 1);
Am I correct in saying in order to call both topics in one callback I have to synchronize the streams ?
using something like ApproximateTime Policy under 7.2 ?
Is it necessary to use both message_filters and image_transport ?
And if so how then do I declare the subscribers ?
What is the difference between message_filters and image_transport ?
Sorry for the confusion.
Thank you