laser scanning and kinect

classic Classic list List threaded Threaded
7 messages Options
Reply | Threaded
Open this post in threaded view
|

laser scanning and kinect

leduchanh
This post has NOT been accepted by the mailing list yet.
I would like to have one question

- For obtaining 3d pointcloud surface of an object, what is the purpose of laser scanning since kinect or stereo vision is enough to obtain a 3D point cloud surface of an object

thank you
Reply | Threaded
Open this post in threaded view
|

Re: laser scanning and kinect

beaverfan
This post was updated on .
In almost all cases, laser scanning is more accurate than the Kinect or stereo vision.  Also with non-detailed surface cases stereo vision does not work because their is not enough unique geometry to identify the points in space between the two cameras. With a laser scanner, the camera is "seeing" the laser and not the geometry.  This way you can scan perfectly flat single colored objects if you had to.

I'll let Jay Leno explain if you want to understand more:

<nabble_embed>http://www.youtube.com/watch?v=q3SVTBrKyZk</nabble_embed>

^^ embeded didn't work:  LINK
Reply | Threaded
Open this post in threaded view
|

Re: laser scanning and kinect

Radu B. Rusu
Administrator

On Sep 23, 2013, at 7:25 AM, beaverfan <[hidden email]> wrote:

> In almost all cases, laser scanning is more accurate than the Kinect or
> stereo vision.  Also with non-detailed surface cases stereo vision does not
> work because their is not enough unique geometry to identify the points in
> space between the two cameras. With a laser scanner, the camera is "seeing"
> the laser and not the geometry.  This way you can scan perfectly flat single
> colored objects if you had to.
>
> I'll let Jay Leno explain if you want to understand more:
>
> http://www.youtube.com/watch?v=q3SVTBrKyZk

:) Awesome.

Best,
Radu.

_______________________________________________
[hidden email] / http://pointclouds.org
http://pointclouds.org/mailman/listinfo/pcl-users
Reply | Threaded
Open this post in threaded view
|

Re: laser scanning and kinect

Aitor Aldomà
any ideas how do they align the different scans of such flat areas?
guess they are using the arm joints to get accurate alignment and don't do any registration at all...?

cheers,
aitor


On Mon, Sep 23, 2013 at 4:34 PM, Radu B. Rusu <[hidden email]> wrote:

On Sep 23, 2013, at 7:25 AM, beaverfan <[hidden email]> wrote:

> In almost all cases, laser scanning is more accurate than the Kinect or
> stereo vision.  Also with non-detailed surface cases stereo vision does not
> work because their is not enough unique geometry to identify the points in
> space between the two cameras. With a laser scanner, the camera is "seeing"
> the laser and not the geometry.  This way you can scan perfectly flat single
> colored objects if you had to.
>
> I'll let Jay Leno explain if you want to understand more:
>
> http://www.youtube.com/watch?v=q3SVTBrKyZk

:) Awesome.

Best,
Radu.


_______________________________________________
[hidden email] / http://pointclouds.org
http://pointclouds.org/mailman/listinfo/pcl-users
Reply | Threaded
Open this post in threaded view
|

Re: laser scanning and kinect

PercocetPenguin
Yes, this uses a single plane laser to create a reconstruction.  Thus there is no search window which can improve resolution.  Camera registration is achieved through joint encoders in the arm.  It's exactly like the "Exact Metrology Romer Arm".

Thank you for your time,
Daniel Moodie
________________________________________
From: [hidden email] [[hidden email]] On Behalf Of Aitor Aldomà [[hidden email]]
Sent: Monday, September 23, 2013 12:24 PM
To: Point Cloud Library (PCL) users
Subject: Re: [PCL-users] laser scanning and kinect

any ideas how do they align the different scans of such flat areas?
guess they are using the arm joints to get accurate alignment and don't do any registration at all...?

cheers,
aitor


On Mon, Sep 23, 2013 at 4:34 PM, Radu B. Rusu <[hidden email]<mailto:[hidden email]>> wrote:

On Sep 23, 2013, at 7:25 AM, beaverfan <[hidden email]<mailto:[hidden email]>> wrote:

> In almost all cases, laser scanning is more accurate than the Kinect or
> stereo vision.  Also with non-detailed surface cases stereo vision does not
> work because their is not enough unique geometry to identify the points in
> space between the two cameras. With a laser scanner, the camera is "seeing"
> the laser and not the geometry.  This way you can scan perfectly flat single
> colored objects if you had to.
>
> I'll let Jay Leno explain if you want to understand more:
>
> http://www.youtube.com/watch?v=q3SVTBrKyZk

:) Awesome.

Best,
Radu.

_______________________________________________
[hidden email]<mailto:[hidden email]> / http://pointclouds.org
http://pointclouds.org/mailman/listinfo/pcl-users

_______________________________________________
[hidden email] / http://pointclouds.org
http://pointclouds.org/mailman/listinfo/pcl-users
Reply | Threaded
Open this post in threaded view
|

Re: laser scanning and kinect

beaverfan
This post was updated on .
In reply to this post by Aitor Aldomà
Aitor Aldomà wrote
any ideas how do they align the different scans of such flat areas?
guess they are using the arm joints to get accurate alignment and don't do
any registration at all...?

cheers,
aitor
The end of the arm is accurate in space to about 0.002" and then the scanner adds about 0.002" more error within the volume of the arm's reach.  If they have to leapfrog for a big part or if they want to scan both sides (eliminate fixturing data) they have to use a program like PolyWorks.  PolyWorks is how they can stitch scans together with common geometry. The geomgery has to be unique enough so that is does not "slide" on each other.  In this case having your common geometry be a flat plane does not accurately restrict all degrees of freedom.

Let me know if you have any questions, this is where I have experience - Romer Arms/Scanners, FARO Focus 3D (long range phase based scanners), hand-held scanners (Handyscan) and PolyWorks for pointcloud postprocessing (aligning, meshing, and inspection reporting compared to CAD models).
Reply | Threaded
Open this post in threaded view
|

Re: laser scanning and kinect

leduchanh
This post has NOT been accepted by the mailing list yet.
In reply to this post by beaverfan
Thank you beaverfan