3D for archaeological finds

One of the most common question we receive about SfM and Computer Vision techniques is: "is it possible to document in 3D also small objects like archaeological finds?". The answer is yes, it is, and there are two possible ways:

1. putting the object to record on a turntable (with a black panel as background) and taking pictures from a fix point  (as I described in this post)
2. taking pictures walking around the object (the easiest way)

Untill now, in both cases, it is better to use Bundler 3 instead Bundler 4 (that seems to have some problems with symmetrical objects). Anyway for option 2 there is no need to "erase the background" so it is possible to use also the newest version of the sofware (which is the one inside Python Photogrammetry Toolbox). This is because other objects in the background can help Bundler to find the right position of the cameras for every picture. the image below is an example of this situation: I took the photos walking around the archaeological find, which was simply placed on a piece of wood (over a normal A4 paper, for metric references).  

3D documentation of arcaheological finds with Bundler and PMVS2

The archaeological find in the picture comes from the mission in Khovle Gora (Georgia) of University of Innsbruck, Department of Ancient History and Near Eastern Studies, (Walter Kuntner and Sandra Heinsch) and Javakhishvili Tbilisi State University (Prof. Vakhtang Licheli).

Python Photogrammetry Toolbox (PPT) and a turntable for 3D objects

I already answered on Pierre Moulon' Blog, but the question Tauricity did is very interesting. The question regards the possibility to document with PPT (Python Photogrammetry Toolbox) an object on a turntable, keeping the camera on a fix position. I had positive results when I tried with Giuseppe Naponiello (Arc-Team's anthropologitst) to document an human skull. We put the skull on a turntable with a black board behind (in this way the software does not recognize nothing exept the turntable and the skull); then we took a picture every 30 degrees. The only problem we had was during data elaboration, cause using PPT with Bundler 4 the software gave us a wrong result (it seems that it confused the two faces of the skull in the axial simmetry). Alessandro Bezzi helped us elaborating the data via shell and using Bundler 3 instead of Bundler 4 (cause he had a similar problem documenting the Theodoric Mausoleum in Ravenna) and this time there were no errors and we could do a dense pointcloud inside PMVS2. So it looks like that Bundler 4 has problems when objects have an axial (the skull) or a radial (the mausoleum) simmetry, but bundler 3 works perfectly.

Anyway it was possible for us to document an object on a turntable keeping the camera fix; the only tip was the black board to "erase" the background, so the software does not recognize points in it (which would be in conflict with the points of the object).

In this video is possible to see the result of the dense pointcloud.