I need to make a subscribe on a topic which has the return to image the camera kinect own turtlebot2

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I'm Using turtlebot2 in my research, and I need to make a subscribe on a topic which has the return to image the camera kinect own turtlebot, or cloud points captured by it, I wonder what the topic should I use in specific and how can I make him subscribe !! I'll be passing these images to an interface that I am creating in real time if tivrem a hint of how to do also the subscriber to my interface would be grateful!

Thank you