Thanks for the update. I haven't played around with republishing too much, but I'll give it a shot again and see how it works. -Dan On Jun 21, 2010, at 6:36 PM, Patrick Mihelich wrote: > Hi Dan, > > On Mon, Jun 21, 2010 at 10:29 AM, Dan Lazewatsky > wrote: > I was wondering what the status of the python bindings for > image_transport is. > > There hasn't been any serious work on Python bindings for > image_transport. > > They would definitely be nice to have, but actually writing them > presents some thorny technical issues. Either you need to write pure- > Python analogues of image_transport *and* all plugins, or find a way > to wrap the C++ implementation and reuse the existing plugins. The > latter approach seems more attractive in terms of code reuse and not > increasing the burden on plugin implementers; but it requires > changing the plugin interfaces to abstract away explicit use of > roscpp (NodeHandle), as that won't play nice with rospy in the same > process. > > In short: this is all possible, just unpleasant and time-consuming. > Since dropping in an extra republish node works adequately, I > haven't made it a priority. > > I've been limping along either using C++ or subscribing directly to > image messages in python, but it's starting to become a problem. The > republish idea on the wiki doesn't seem like a particularly good > solution. > > Sometimes it is actually the best solution! If the image topic is > published on machine A and there are multiple subscribers on a > machine B, republishing the images in raw format on machine B > minimizes both network bandwidth and CPU usage. > > For the one-to-one case - only one subscriber on the second machine > - it's true that spinning up a republish node is an inconvenience > and adds a little latency. I'd suggest adding it to your subscriber- > side launch file. > > Cheers, > Patrick > _______________________________________________ > ros-users mailing list > ros-users@code.ros.org > https://code.ros.org/mailman/listinfo/ros-users