Need some insight about the meaning of the cloud resolution value

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Need some insight about the meaning of the cloud resolution value

lilouch
Hi,

I would like to have some help about the meaning of the resolution value.
In this  link
<http://pointclouds.org/documentation/tutorials/correspondence_grouping.php>  
- referring to the pcl documentation - there is a function that allows to
compute the cloud resolution.

In my problem, I have different objets of different resolutions. (by using
the given function).
For example : object1 has a resolution of 0.01 and object2 has a resolution
of 0.001.

I have two questions :
- What is the meaning of this value ?
- How can I set the same resolution for both object ? Since If I do
matching, I need to have about the same resolution. I notice that by doing
some test.

Could you please help me ?

Thank you in advance



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Re: Need some insight about the meaning of the cloud resolution value

MarkL
Resolution in that tutorial is the mean distance between points in your cloud
(1 / density).

You can downsample the cloud with the higher resolution using VoxelGrid
(leaf size = resolution):
http://pointclouds.org/documentation/tutorials/voxel_grid.php

It should also be possible to upsample with MLS:
http://pointclouds.org/documentation/tutorials/resampling.php
It has several upsampling methods -
http://docs.pointclouds.org/trunk/classpcl_1_1_moving_least_squares.html#aa444c1e8df3498adba7f25918f4a961c

But to be honest, I don't think you need it. Aligning clouds with different
resolutions shouldn't be a problem. In fact, I've been downsampling my Input
cloud to speed up the process, and didn't notice a negative effect on the
quality of alignment.
Just make sure that the cloud with the higher resolution (more points) is
the one that is used as the Target. If you need it the other way around,
just take the inverse of the final_transformation.


lilouch wrote

> I would like to have some help about the meaning of the resolution value.
> In this  link
> &lt;http://pointclouds.org/documentation/tutorials/correspondence_grouping.php&gt; 
> - referring to the pcl documentation - there is a function that allows to
> compute the cloud resolution.
>
> In my problem, I have different objets of different resolutions. (by using
> the given function).
> For example : object1 has a resolution of 0.01 and object2 has a
> resolution
> of 0.001.
>
> I have two questions :
> - What is the meaning of this value ?
> - How can I set the same resolution for both object ? Since If I do
> matching, I need to have about the same resolution. I notice that by doing
> some test.
> _______________________________________________

> PCL-users@

>  / http://pointclouds.org
> http://pointclouds.org/mailman/listinfo/pcl-users





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