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Object strobing
Dawson from Malaysia  [173 posts]
12 year
If i strobe an object (at a fixed frequency) in a scene, can roborealm mask out the scene leaving only the area of the strobing light and making this into a blob. This would be helpful in allowing a vision system to isolate certain objects in a scene.
Anonymous 12 year
Yes, this should be possible. I am assuming that the strobe would make a single object lighter than the rest of the scene? If that assumption is correct then you could use the Movement module to detect the light change and 'set movement to actual' to view the raw object pixels.

You will have to play around with the frequency of the stobe (or perhaps let RR control that) in order to get a set of images without and then with the strobe.

Or if you have issues try posting a zipped video here or somewhere that we may have a look at what could be done.

STeven.
Dawson from Malaysia  [173 posts] 12 year
The entire scene may have spots where the light intensity is higher or equal to the light reflected from the object being strobed (outdoors). Also i forgot to mention that the robot would be moving so the entire scene would be changing. In this case would the movement module still be applicable? Sorry i don't have a video of the scenario.
Anonymous 12 year
Dawson,

If this light is capable of illuminating the entire scene including background objects that using then strobing light would not make much of a difference in terms of object segmentation. Ideally you would have the light change the appearence of just the object you want to segment from the scene otherwise you are back to the same problem that just using a normal light would require ... i.e. some specific attribute of the object that you want to detect that is different than the others.

This still may work as if the object you want to detect does increase overall more than anything else in the scene (i.e. its the closest object to you) that this may still work. Perhaps you should include two example images here in the forum for us to get a better idea and talking point. One image would be without the light and the other with.

I assume this is for obstacle avoidance?

STeven.
Dawson from Malaysia  [173 posts] 12 year
Yes you are right. It is for obstacle avoidance. I am anticipating that the closer objects will appear brighter. Thanks
Dawson from Malaysia  [173 posts] 12 year
The purpose of strobing is to differentiate bright areas in the scene with continuous light and areas where the light is strobing. Yes you are right in that if these areas overlap then the system wont be able to differentiate them. Thanks.
Anonymous 12 year
Dawson,

There are a couple of factors needed to make this work. I'd highly recommend taking a couple images to see if this will work.

Note, we've done this before with IR cameras. Works reasonably well but the color/reflective properties of the objects becomes a big issue.

STeven.
Dawson from Malaysia  [173 posts] 12 year
STeven,

Yes and the fact that the robot (and the camera) is moving complicates things further (not possible to compare frames). I think this idea would only work if RR was able to sync with the external strobing light source (or if the camera was static i.e. separate from the robot)
IR cameras (850nm) doesn't work in my case due to "wood effect" of surrounding foliage (it clouds out objects).

Dawson
Dawson from Malaysia  [173 posts] 12 year
STeven

Yes you are right. Surface reflection, texture and color pose major problems. I might be better off using another strategy such as flood fill or segment colors. I am still in the planing stage and have not started the build yet. Thanks for your advise.

Dawson

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