Feature request: Add support for visualizing YUV image formats

[asobhy-qnx]

Most cameras in the field output data in YUV formats. It would be nice to add support for visualizing image msgs of YUV formats and not just RGB. This could be implemented by converting YUV to RGB within rviz and then visualizing it.

So if the encoding field in the Image msg is yuv then do the conversion in rviz2 to be able to see the video feed, https://github.com/ros2/common_interfaces/blob/master/sensor_msgs/msg/Image.msg

[asobhy-qnx]

@clalancette what do you think of this?

[clalancette]

Sure, it seems like a reasonable enough request. Please feel free to submit a PR for it.

[asobhy-qnx]

Great! Yes we can work on it 👍