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How to republish image to multiple topics with CameraInfoManager?

asked 2017-10-19 08:11:03 -0600

omrikoresh gravatar image

updated 2017-10-19 11:28:01 -0600

lucasw gravatar image

Hello, My program takes the capture image from a webcam and dividing it into 4 images by splitting the main capture. I want to publish those 4 images in a 4 different topics in the same ros package, same cpp file, but when I try to do that with creating 4 different camera_info_manager I get the error:

Tried to advertise a service that is already advertised in this node [/camera/set_camera_info]

Any ideas how to solve my issue and how to create 4 different rostopics ? thanks.

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answered 2017-10-19 11:24:09 -0600

lucasw gravatar image

updated 2017-10-19 11:27:12 -0600

Create four different nodehandles with four different names:

ros::NodeHandle nh1("image1");
ros::NodeHandle nh1("image2");

And then create four ImageTransports and so on:

image_transport::ImageTransport it1(nh1);
image_transport::ImageTransport it2(nh2);

then you'll get four different camera_info topics:


Or skip having four different camera_infos, use a regular ImageTransport::Publisher instead of CameraPublisher, just publish the image from four publishers (building off of ) from the one ImageTransport but any subscriber should have camera_info remapped to the original source one. Even if you are doing something like splitting the images where only every 4th image goes out on the 4th topic, a subscriber that cares about camera_infos will match it up with the right one and ignore the other three camera_infos that don't correspond to any received images (though some nodes will output some warnings about this, they should still function fine).

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Asked: 2017-10-19 08:11:03 -0600

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Last updated: Oct 19 '17