we are publishing an image in ROS2 with a resolution of 600 by 600. Using rclpy in Python, the callback is very slow. We ran the ros2/ros1 bridge and made a very similar ROS1 subscriber and the performance is perfect.

We tried using opensplice and fastRTPS, but since using the ROS2/ROS1 bridge callback works perfectly, we are confident it isn't the transport layer and the problem is probably with the python subscriber cash.

The cam2image example uses such a low resolution that the problem doesn't appear.