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The ‘Brotlaibidole’ are small baked-clay objects of prevalently ovoid shape of the 2,100-1,400 B.C. periods, engraved with symbols and drilled holes whose meaning is still unknown.
Their presence in Italy and in many countries in the northeast Europe represents an ‘enigma’ for the specialists.
The reason is that the shape and the orientation of the signs is
very similar among the objects, even if they have been found in
different geographical sites.
Hence, we have been required to accomplish an
extensive measurement campaign in Europe, and to produce and collect
the 3D models in a unique database, in view of their
future study by the specialists. To carry out the measurement, we used
the Vivid 910 sensor (Konica Minolta Inc.). Besides the measurement
performances, that well suit to the resolutions required in this
application, the system is rugged, portable, and fast in the setup and
the acquisition processes. So far, 30 specimens have been acquired,
modeled and organized in a database. Their resolution is 120μm.
Following the acquisition and point-cloud elaboration, we carried out a selection of symbols to be compared. The different symbols were extracted from the models and properly oriented in a suitable reference frame.
Symbols from different “pieces” were then superimposed and aligned, in a totally automatic way.
Color coding was used as a user-friendly way to obtain information about the amount of overlapping between the two symbols. All these steps were performed by the self developed “ATEC-3D” software: a user-friendly environment, specifically intended to be used by a non software expert such as an archaeologist.
In the ATEC-3D panel, the signs to be compared are chosen, and they appear as 3D models. Point clouds and their superposition in color coding are presented after suitable automatic registration and distance compensation. An index of similarity (rms value of the differences) is obtained to quantitatively assess the goodness of overlapping.
This process has been tested on a suitable number of self-made signs used as references, printed onto clay surfaces under different angles and with different pressures.
The ATEC-3D software has been delivered to the archaeologists, who have now started the overall comparison of all signs derived from the 30 models, whose 3D acquisition has been made and whose signs are now in the common database.
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