Pepper: Getting the distance to a Land Mark

Question

I am researching the ALLandMark module. How can I get the distance to detected Land Mark or the position of it?

I have tried to register Land Mark with ALTrackerProxy::registerTarget and then get the position or the coordinates of the target with:

ALTrackerProxy::getTargetCoordinates - returns empty list []
ALTrackerProxy::getTargetPosition - returns None

My idea is when Pepper detects Land Mark to navigate to it.

How can I get the distance to detected Land Mark or the position of it?

score 3 · Answer 1 · answered Dec 20 '17 at 13:59

3

The distance is completely relative to the printed size.

You can use a simple empirical ratio from the sizeX and sizeY found in the shapeInfo.

(in fact you could compute this ratio, using the specs from the camera, but it's nearly quicker to test it)

The real way is to use the OpenCV PnP method: basically you enter the position of the mark in the image, plus the camera information and it gives you the position in the world.

answered Dec 20 '17 at 13:59

Alexandre Mazel

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if it is possible for you, could you please provide some example / tutorial, because I am new to OpenCV. – stefan.stt Dec 21 '17 at 09:49
https://stackoverflow.com/questions/18637494/camera-position-in-world-coordinate-from-cvsolvepnp – Alexandre Mazel Jan 03 '18 at 10:46

score 0 · Accepted Answer · answered Jan 04 '18 at 09:46

0

Here Aldebaran have posted very good example(No.3: Landmark localization) how this could be done.

answered Jan 04 '18 at 09:46

stefan.stt

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Pepper: Getting the distance to a Land Mark

2 Answers2