SFM software - Point cloud alignment

[luca]

Hi Ricardo, i answer below

On 08/01/11 21:22, Ricardo Gaidão wrote:
> SFM software like Bundler, PMVS2, CMVS enable to create accurate colored point clouds from digital photos.
>    

All this package are already included in archeos 4. Alessandro developed 
also a small GUI in Pyqt to let them use also by newbies.

> Meshlab can be used to rescale those point clouds and create colored meshes using point color information.
>    

Yes, in this way Meshlab works very good.

> Unfortunately remains the problem of point cloud alignment.
>
> Nathan M. Craig and Mark Willis developed methods to assign real word coordinates to this point clouds.
>
> The process is something complex and demands many steps.
>
> For majority of archaeologists an automatic point and click solution would be better.
>    

With some GCP (Ground Control Point) in the photos is not a problem for 
the alignment. Meshlab has a specific tool. Alessandro and me can write 
a tutorial about it as soo as we finish the work for ArcheOS 4 (when the 
alpha will be released). We are already working in this way in the 
excavations.

> Maybe some kind of Meshlab plugin, that allow the user to individually select and edit some reference points in the model. Making possible to attribute them real world coordinates.
>
> Other secondary problem is the lack of a solution to transform the photos used by SFM software into textures to map the models created from those point clouds.
>    

Inside Meshlab is also possible to build the textured model (just in two 
steps, if i remember well). Also for this we will write a tutorial as 
soon as possible.

> Ricardo
>
> References:
>
> Structure from Motion Point Clouds to Real World Coordinates (Nathan M. Craig):
>
> http://www.personal.psu.edu/nmc15/blogs/anthspace/2010/02/structure-from-motion-point-clouds-to-real-world-coordinates.html
>
> How to create a Digital Elevation Model from Photosynth point clouds (M. Willis):
>
> http://palentier.blogspot.com/2010/12/how-to-create-digital-elevation-model.html
>    

There will be a lot of work in writing tutorial. The problem is that it 
is better to wait a first release of ArcheOS 4 before to start. That's 
way we stop with the tutorial: there are some differencies between 
ArcheOS 3 and 4 (basically because the 3 is based on Kubuntu and the 4 
on Debian), so to avoid to continuosly update the tutorials, we are 
waiting for ArcheOS4. We hope to be able to release it soon (what do you 
think, Fabrizio?), actualy there are just some minor bugs to fix.

Reguarding Bundler-CMVS-PMVS, the situation actually is this:

- We solved the problem of the featrue detector SIFT (shareware, that we 
could not distribute) with Vlfeat (GPL, a little bit slower, but also 
more accurate), so naw tha package is complete. No post-installation 
operations have to be done by users (so it is also more simple for newbies)
- alessandro developed a simple GUI
- in the next feature i think that all the package will be insert in Meshlab

We are working in collaboration with other people interested in this 
field (expecially Pierre Moulon). I you want to hel us, we will be very 
happy. :)

Bye

>
> ********************************************************
>
> Luca said (Sun Dec 5 10:48:23 CET 2010):
>
> Hi all,
> It looks like that the issue for ArcheOS 4 are no more so many (more or
> less 10% in the roadmap). On the other hand all the release goals seems
> to be OK:
>
> 1 repository (OK)
>
> 2 deb packages of archaeological software (OK)
>
> 3 adding software of Computer Vision for SFM (Structure From Motion):
> Bundler, PMVS2 (OK, and in the meantime we added also CMVS)
>
> 4 adding software for semi-automatic drawing of finds: stippler (OK)
>
> I am thinking that maybe we could choose a date to release ArcheOS 4
> alpha. In this way we can concentrate on the final issue, release the
> distro and fix all the minor bug later (also looking the issue of the
> user/tester).
> E.g. new paclages can be added to the repository in a second time, new
> artwork can be uploaded in the wiki with the instruction for the user
> (how to change the wallpaper, etc...).
> Anyway, after a while we can release a beta with all the bugs fixed,
> till the final release.
>
> What do you think about it?
>
>
>
>
>
> --
> Mailing list info: http://lists.linux.it/listinfo/archeos-dev
>
>