Posted by matlabbe on URL: http://official-rtab-map-forum.206.s1.nabble.com/About-CommonDataSubscriberRGBD-code-research-tp7127p7152.html
There are multiple ways to subscribe to image topic. When subscribe_rgb and subscribe_depth are true, you can do "rosnode info rtabmap" or rqt_graph to see which image topic it is subscribed to.