Groundbased_rgbd_people_detector

[aichim]

@nizar-sallem , @mmunaro

I am playing with the people detector, and the plane selection is really messed up. I click on some points, and get completely random points in the scene. They seem to be rolled around the z-axis by 180 degrees (see the screenshot). But I cannot seem to find the problem in the code. Nizar, can you have a look, the code is super short in apps/main_ground_base_rbgd_people_detector.cpp ?

Thanks guys!

[mmunaro]

Hi Alex,

sorry for the late reply.
It is a weird behavior, It does not happen to me...
I experienced that the points can be badly selected when there is an object more or less on the same direction but nearer than the ground plane point that I am selecting.

Try to click on the ground plane where the point cloud is more dense and be sure that there are no obstacles near there (maybe zooming on the ground plane could help).

Cheers,
Matteo

[mmunaro]

Hi Alex,

I just updated my code with the latest trunk and I experienced the same error you reported!
With trunk version before the 28th of May the clicking on the ground plane points was working, but now something should have been changed somewhere...
The Kinect point cloud seems to be upside down when it is shown by the visualizer with respect to how it was visualized some days ago.

Do you think that Nizar can understand what could be the cause?

Cheers,
Matteo

[mmunaro]

The code is working (the coordinate of the points is correct), but the visualization of the Kinect point cloud or of the clicked points is wrong (z coordinate is inverted). From the image below, it seems that Kinect point cloud is wrongly visualized (points have negative z value). It seems to be caused by a change to the visualizer, but I do not know how to fix it and I do not think I should change my code.

[nizar-sallem]

I agree with the explanation given above by mmunaro seems kinect point clouds are flipped.
I am trying to get a fix for other stuff we noticed not working properly maybe this will be fixed as well. Please be patient just a little more, I am compiling/testing right now, it is a bit long cause my laptop is not super fast.

[mmunaro]

Hi Nizar,
did you manage to understand what is causing this problem?

Cheers,
Matteo

[mmunaro]

Hi Alex and Nizar,
the visualization problem started after this commit:

Merge pull request #92 from nfioraio/master
Better support to point cloud pose setting in PCLVisualizer
789fb08

The last good and bad commits were:
last good: b16dff1
last bad: a49df4c

What was meant to be introduced with this commit?

Cheers,
Matteo

[jspricke]

Hi Matteo,

it doesn't really make sense to identify the merge as the broken commit. Is there some easy test, so I can try it as well?

[mmunaro]

Well, I was using git bisect, but I found some not compiling versions of the code, thus it could not finish...
However, if you run pcl_ground_based_rgbd_people_detector in the bin folder with a Kinect/Xtion attached, you can easily check for the problem:

• if you see the point cloud in the visualizer at the beginning, then the point cloud is correctly visualized
• if you have to turn the visualizer upside down for seeing the point cloud, then there is the problem.

[jspricke]

Hi,

based on Matteos tests I've found that it would be enough ti remove this and the next line to fix this: https://github.com/PointCloudLibrary/pcl/blob/master/visualization/include/pcl/visualization/impl/pcl_visualizer.hpp#L1247. On the other hand, this is part of a bigger change to support the sensor origin fields, so maybe adding an appropriate one would help as well. @nfioraio what's your opinion on this? Can you come up with a solution?

[mamoto]

hi, another issue flip in addPointCloudNormals

[mmunaro]

In my opinion, here, the normals are correctly drawn, but the point cloud is flipped.
It is the same issue as in the people detector: the clicked points and the people bounding boxes are correctly drawn, but the point cloud is flipped.

[mamoto]

i had same issue in the people detector point cloud flipped. did anyone solve this issue ? (*_^)

[jspricke]

Sounds like #92 needs some more work. I'm reverting it for now. Please report back if this fixes all problems.

[mmunaro]

Ok, I will let you know tomorrow, because I cannot test it now.

[mamoto]

it solved!! thank you!!