Compressed Image Display

[mjforan]

Addresses #738

I added RosTopicMultiProperty, which extends RosTopicProperty with a list of message types instead of one single type. This allows the ImageDisplay to show raw and compressed image topics together in its selector list. ImageDisplay was altered to use an image_transport subscriber so it can seamlessly display any installed image type. There is also a handful of frivolous changes to comply with the style linters.

Tested with raw and compressed images. Assuming the other types work as well because the conversion happens in the image_transport library.

Uncertainties:

• RosTopicMultiProperty: Is the name ok? Is there a simpler way to achieve my goal without adding a one-off property?
• plugin_description.xml: I added the other image_transport topic types here so Image Display appears in the "Add/By topic" menu. Adding the display will fail if the associated image_transport plugin is not installed. Should ros-$ROS_DISTRO-image-transport-plugins be added to package.xml?

[mjforan]

Added a property to manually override image transport type. Rviz determines the transport by checking the topic name against image_transport conventions, e.g. camera_name/raw, camera_name/compressed, etc. If this is not the case, the transport must be set manually.
I also fixed the crash caused by adding a topic with an unavailable transport. Instead it will provide an error on the status property saying the transport is not installed.

[ahcorde]

This is wierd

I had a default rviz.config file with an image display and Rviz2 crashes, do you mind to take a look ? we don't want to break user.

[mjforan]

@ahcorde

This is wierd

Sorry about that, I have pushed a fix.

I had a default rviz.config file with an image display and Rviz2 crashes, do you mind to take a look ? we don't want to break user.

Please provide details so I can reproduce your issue.

[mjforan]

I would like to list the available image transports in a status message. However, setStatusStd only seems to work when it is called from subscribe, not onInitialize or updateTopic. Any idea why?

The status message doesn't really matter except the transport->message type map is hard-coded, so we will want a warning if a new transport type is used which does not exist in the map.

[mjforan]

I noticed the Jazzy version of image_transport finally allows passing in custom QoS so I updated the API here to match. This change is not compatible with previous versions of ROS.

[mjforan]

Can ImageDisplay be combined with the parent class ImageTransportDisplay? That would allow CameraDisplay to also show compressed image topics.

[ahcorde]

Pulls: #1288
Gist: https://gist.githubusercontent.com/ahcorde/753b92fff53f4ae45626059ba1fca518/raw/8ba713dd713ffadefa3801686787117bf9f33380/ros2.repos
BUILD args: --packages-above-and-dependencies rviz_common rviz_default_plugins
TEST args: --packages-above rviz_common rviz_default_plugins
ROS Distro: rolling
Job: ci_launcher
ci_launcher ran: https://ci.ros2.org/job/ci_launcher/16039

• Linux
• Linux-aarch64
• Linux-rhel
• Windows

[mjforan]

The "unstable" builds are caused by GitHub rate limiting. I think they changed something recently because I have been seeing it frequently in my own CI processes.

[ahcorde]

The "unstable" builds are caused by GitHub rate limiting. I think they changed something recently because I have been seeing it frequently in my own CI processes.

This is is related with RViz in particular with rviz_default_plugins.image_display_test, there is a segfault

[mjforan]

Oh, I see now. That must be the result of some changes outside of this PR because it was not failing in March. I will look into it.

[ijnek]

We would like to get this PR over the line. Is there anything we can do to help here?

[mjforan]

@ijnek sorry, I am in the middle of a cross-country move so I haven't been able to look at this for a while. As of May a new segfault was the only blocker for this PR. I can't provide much support right now but I'll be on it again in a month or so.

[mjforan]

@ahcorde The test build reports errors apparently stemming from point cloud display updates in 7248938. Everything builds successfully on my system so maybe there is a problem with the automated build setup.

[mjforan]

I putting this PR on hold until the issues regarding abstract node interfaces are worked out.

[JoLichtenfeld]

Hi, is this PR still active?
I think the RosTopicMultiProperty could also be useful for the PointCloud2TransportDisplay.

This suffers from the same problem that topics of type point_cloud_interfaces/msg/CompressedPointCloud2 are not shown in the display's dropdown topic selection.

Would it make sense to move this (RosTopicMultiProperty ) to a separate PR? Then I could continue working on the PointCloud2TransportDisplay.

[mjforan]

@JoLichtenfeld
Yes. After Dec 25 I will get this going again.
If that is not soon enough, you're welcome to split out what you need into a separate PR.

[JoLichtenfeld]

@JoLichtenfeld Yes. After Dec 25 I will get this going again. If that is not soon enough, you're welcome to split out what you need into a separate PR.

Perfect, then I will wait for it.

[mjforan]

I'm encountering memory issues in the compressed image transport plugin (deb package) but can't reproduce with a source build. They are both on the most recent version (6.2.2).
Maybe it is something particular with my setup. @ahcorde could you please run the test suite?