Friday, 30 March 2012
One of the most interesting presentation we have seen in Southampton (CAA 2012) was the one of Jitte Waagen (Amsterdam Archaeological Centre, University of Amsterdam), regarding "Learning Sites" (a free and open source communication and data-exchange tool for archaeological field-work and education). Jitte said that by now they use net-books and GPS for their project, but they planned to port sooner or later everything on Android smartphones or tablets. Their problem, if I understood well, is that they need a portable version of QGIS for Android, as their project is based on this desktop GIS.
I could not help them in Southampton, because I did not remember exactly where to fine informations about QGIS and Android, but now that I am back home I can check ATOR and find Gunther's report (in Szabo's post) about this topic. Here is the text:
I do not know if you know the QGIS project for android? I think it might be interesting in the context of field work with the android tablets.
The website Gunther suggested is very interesting (I added in the "interesting blog" list) and from there I jumped here: http://hub.qgis.org/projects/android-qgis, where I found more information about the project to develop an Android version of QGIS. Here is a screensot of the website:
So I hope that this post will be useful for Jitte (if he will ever read it...) or for anyone who could be interested in Android an QGIS and I want to thank again Gunther for his report. I also want to remind the two posts of Szabo about the tool he is developing for Android (excavation-oriented): ArcTeamFindings (Android app) and http://arc-team-open-research.blogspot.it/2012/01/arcteamfindings-android-app-new-style.html.
Wednesday, 28 March 2012
today we will present in CAA2012 in Southampton (GB) the result we obtain using Structure from Motion techniques with aerial images. The hardware we used are:
- Nikon CoolPix S210
- Gopro HD Hero
The software are:
-Python Photogrammetry Toolbox
The picture below shows the three different phases of work (data acquisition, data processing and final result)
The two cameras made different results: the 3D model of the Nikon is more dense, but using the Gopro it is possible to have bigger terrain model.
In the next days we will upload the slides of the presentation.
Thank to Walter Morelli and Walter Gilli which help us in this research.
Monday, 26 March 2012
This year the Computer Applications and Quantitative Methods in Archaeology (CAA) conference will be hosted by the Archaeological Computing Research Group in the Faculty of Humanities at the University of Southampton on 26-30 March 2012. Unfortunately we will have no time to stay the whole week in Southampton, but we will participate to the session regarding "Novel Technologies For Supporting Archaeological Fieldwork" which will take place Wednesday, March 28. Our presentation ("Free and Open Source platform for remote sensing and 3D data acquisition") will focus on the combination of open source UAV (especially the UAVP drone) and ArcheOS. We will show as well some results about our last project of aerial archaeology in North Italy.
I hope it will be an interesting experience (just to write some report about it). For more information about the congress, here is the official website: http://caaconference.org/.
Soon we will post the presentation, and some more details about our last research in UAV field.
Tuesday, 20 March 2012
Friday, 16 March 2012
I received many feedbacks for the two posts about gvSIG 3D (gvSIG 3D and gvSIG with SfM data). I think the most important thing about the possibility to import 3D data in gvSIG with the obj format is that in this way we can import the two main kind of 3D data normally we have in archaeology:
- 3D documentation
- 3D reconstruction
Considering as fourth dimension for this data the value t (time), so that each single point has three spatial dimension (x,y,z) and a temporal dimension (t), we see that in archaeology the concept of documentation and reconstruction are very different.
In this short movie, in which I registered in gvSIG 3D the two 3D dataset I used for the test, it is possible to understand better this difference.
The burial is a 3D documentation, done in March 2010 and recording the situation in which we found the archaeological evidence after its deposition and all the post-depositional alterations. From a 4D point of view its time value (t) is March 2010 and it is connected with a single event: the discovery of the burial, which archaeologically can be considered as the last event in the "micro history" of the object.
The church is a 3D reconstruction which hypothetically describes the building in one of its "life cycle" stages, after its initial construction, and, more precisely, during the XIX century. From a 4D point of view its time value (t) is XIX century and it is connected with a period (after the architectural changes of the XVIII century and before the minor building modifications of the XX century). In short it is a hypothetical reconstruction of one of the post-depositional alterations of the object.
Another difference between this two kind of 3D data regards the techniques with which the 3D model are done. The burial was documented with Structure from Motion and Image-Based Modeling techniques (Python Photogrammetry toolbox), while the church was reconstructed with a 3D modeler (Blender).
The final difference is related with the normal work-flow of an archaeological project: the 3D documentation is done during one of the first stages, consisting in the archaeological excavation, while the 3D reconstruction is done just at the end of the whole process, after analyzing all the collected data.
In other words the main news about gvSIG 3D, from an archaeological point of view, is the possibility to handle in a GIS 4D data (x,y,z,t), following the natural evolution in the discipline methodology.
Monday, 12 March 2012
The presentations that impressed me the most during the workshop "Low cost 3D: sensori, algoritmi e applicazioni" (Trento, 8-9 March 2012) were the those of FBK's researchers and especially: "Tecnologia TOF per 3D imaging – low-cost o no?" (L. Gasparini, D. Stoppa) and "Caratterizzazione di sensori attivi e passivi low-cost" (F. Menna). One of the topic of these contributes was Kinect and the level of detail, accuracy and precision this instrument can reach. In particular it was said that using Kinect with a distance of 50 cm it is possible to record 3D scenes with an error of more or less 2 mm.
Alessandro and me already tested Kinect in ArcheOS (on Ale's laptop) during our teaching experience in Lund University, but in that occasion we did not check the level of accuracy. For this reason Alessandro compiled RGBDemo on my laptop during the workshop and, thanks to the coffee break, we tested it with some researchers reaching an accuracy of 1 mm.
This evening I repeated the experiment at home and here is the video of RGBDemo Reconstructor during data acquisition:
The yellow square you see in the movie is a normal folding meter and its side is 20 cm long. Here is a more detailed picture of it:
In this other movie I checked the accuracy I reached within MeshLab. When I measured the side of the squared the result was 0.198 m (better seen in full screen...).
I think this level of accuracy is more then enough for archaeological applications. Anyway I will go on with other test in the next months, hopefully with something more professional than my living-room :).
Tuesday, 6 March 2012
Saturday, 3 March 2012
Just a fast post to confirm that it is possible to import SfM data in gvSIG 3D, like I supposed wednesday.
I tried again with data from Arc-Team's excavation of St. Andrea's church in Storo (TN, Italy): in the image you see the documentation of "tomba 2" ("grave 2"), done with Structure from Motion techniques (Python Photogrammetry Toolbox). I elaborated the pointcloud in Meshlab, obtaining a textured mesh. Then I upload the file in gvSIG 3D.
Finally we have a fast way to import 3D documentation (PPT and Meshlab) and reconstruction (Blender) inside a GIS (gvSIG)!