sync between disparity image and rectified image

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Hi,

I'm running stereo_image_proc to get rectified images as well as disparity images. And then I have a bunch of processing nodes that work with these. For a particular application, I need the pair of them together (rectified image and the corresponding disparity image).

Now since these are both published on individual topics, due to whatever reason (latency, processing etc.) sometimes they go out of sync. And so I have some code to read the headers and decide if these are the same pair or not. This seems not ideal to me.

Is there a better way to get a rectified image and the corresponding disparity image or point cloud message "together" somehow? Does image_transport have something for this?

Thank you.