Two Cameras and Optical Flow module?
14 year
I'm considering playing with two cameras instead of one on a new robot project. But it seems like the way roborealm is set up certain modules will look at the history of image(s) from one image stream, but not do comparisons between two streams. For instance:

I was thinking of trying to use optical flow to compare between what the left camera "eye" and right eye see in each frame. And letting the flow vectors tell me what parts of the field of view contained something close (larger displacement between frames). But to do that, I'd need to use something like the "marker" module to somehow toggle between left cam and right to produce the flow field. But I'm not sure how to do that or if it's possible at all.

If it is, is there a code fragment somebody could post so I can cop a clue on this one?

Thanks much.

- Z
Anonymous 14 year
Z -

Yes,use the search tab to search for Stereo and try that module out. It is a faster version of the optical flow between two images meant to be used in stereo analysis. It will take a bit of parameter tweaking to get it to work correctly so if you can't get it right please post the two (left right) images here and we'll see what we can do.

Note that stereo searching is simply optical flow restricted to the horizontal axis ... which makes it much faster since the search is 1D (line) instead of 2D (box).

Anonymous 14 year
STeven -

Is that an undocumented/beta module?

- Z
Anonymous 14 year
Correct. The module works but uses the standard SSD technique which is both slow and not very precise. We have another modules in development that is much superior to this one and thus will most likely be removed/replaced when that one comes out. For now it is mainly a placeholder and used occasionally mainly for testing purposes. (Note that most stereo programs use exactly the same SSD windowing technique so it is somewhat a standard way of doing stereo... but in our opinion just not a very useful one! )

Zain Saidin from United States  [2 posts] 14 year

It's going to take me a bit to get my two camera junk set up, so I'll play around and get back to ya. In the meantime a couple thoughts as you develop newer flow modules.

I still think it would be cool to have optical-flow take two camera inputs, or alternately for "stereo" to be able to run in more than the single axis when doing the calculations. The reason being that it could make sense to have two camera with different lens/FOV/zoom selected, but looking roughly co axially at the area in front of a robot. The flow field between the two different image sources would then highlight objects/regions for depth/distance calculations. Could that make sense?

- Z

This forum thread has been closed due to inactivity (more than 4 months) or number of replies (more than 50 messages). Please start a New Post and enter a new forum thread with the appropriate title.

 New Post   Forum Index