What is extrinsic_in_camera_frame parameter

Hi,

I see the parameter called “extrinsic_in_camera_frame” and its description in the ZED ROS SDK here. I’m trying to understand it to make sure it’s not causing me issues.

However, I don’t understand what it refers to when it says "an extrinsic parameter in camera_info ". Looking at the Camera_info message, it makes no mention of an extrinsic value.

Also, why would we want this extrinsic value to be in the camera frame? And in what scenario would we want this extrinsic value to be in the ROS native frame? I was thinking since we’re using ROS we would always want to use ROS’s coordinate system (X Forward, Z UP). Thank you. I want to understand this to make sure this single parameter isn’t messing up my whole pipeline.

Hi @orrblue
sorry for the late reply.

When the zed-ros-wrapper was initially designed it published the extrinsic parameters in “camera frame” instead of using the default ROS frame (X FWD, Z UP).
We fixed this behavior in the ZED SDK and we forwarded the modification to the ZED ROS wrapper.
For users that were using the old behavior we added the extrinsic_in_camera_frame parameter to continue using it without changing their code.

In the camera_info message the extrinsic parameters are used in the R matrix: