One big subscriber vs. multiple small subscribers?

Question

I'm using rospy.

I have several nodes that need camera image and point cloud.

each of them needs to get the rgb image and point cloud in real time.

I'm thinking about 2 structures

1. Create one node that subscribes image and overwrites them into jpg file. And Create another node that subscribes point cloud and overwrites them into psd file. Nodes open files

2. Put 2 subscribers to every nodes.

which is better(speed, synchronization)?

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Originally posted by gliese581gg on ROS Answers with karma: 1 on 2016-01-11

Post score: 0

Answer 1

If you're worried about the overhead of multiple subscribers for high bandwidth/frequency topics like images and pointclouds, what you want is probably nodelets. From the wiki page:

Nodelets are designed to provide a way to run multiple algorithms on a single machine, in a single process, without incurring copy costs when passing messages intraprocess.

However, it has been said that "premature optimization is the root of all evil." I would recommend that you first try having your nodes subscribe independently as normal and see if you actually need to do anything fancier.

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Originally posted by Dan Lazewatsky with karma: 9115 on 2016-01-11

This answer was ACCEPTED on the original site

Post score: 3