Depth Image Proc: Consider replacing SystemDefaultsQoS

[SteveMacenski]

There are many places that SystemDefaultsQoS is being used in the Depth Image Proc. I might suggest setting the depth to 10 or using the rclcpp::QoS profile instead. SystemDefaultsQoS has a default queue size of 1 for Fast-DDS and infinite for Cyclone.

We are in the process of removing SystemDefaultsQoS from Nav2 for this reason and this ticket comes out of a quick audit of the ecosystem of anywhere else a change would benefit ros-navigation/navigation2#4888

[galou]

Shouldn't rclcpp::SensorDataQoS be used instead for subscribers?

[galou]

I see in the official doc:

"Most components in image_pipeline follow the Quality of Service (QoS) recommendations of REP-2003 by default. This means that subscribers are configured with the “Sensor Data” QoS (which uses “best effort”), and publishers are configured with “System Default” QoS (which uses “reliable” transport)."

SensorQoS should be used in subscribers in Rolling. I'm using Humble and got "requesting incompatible QoS. No messages will be sent to it. Last incompatible policy: RELIABILITY_QOS_POLICY ".