Church of the Holy Apostles

Church of the Holy Apostles, Greece

Digitisation of Church of the Holy Apostles - Aerial data collection phase - Camera low angle oblique session

Location: Thessaloniki, Greece

Institute: Athena - Cultural & Educational Technology Institute (CETI)

Description Icon

Description

The Church of the Holy Apostles is situated in the homonymous square in Thessaloniki, at the beginning of the modern Olympou Street. It lies south of the decumanus (Saint Demetrius Street), around 50 meters from the west city wall, near the Litea Gate, now a ruin. Originally it was the katholikon (main church) of a sizeable monastery. Except for the church, little evidence remains today from the original complex, such as parts of the precinct, a gateway to the south of the katholikon and a large cistern to its northwest. Initially the monastery covered an area of more than 10.000 square meters. The dating of the church’s construction (along with its bell tower) is part of an ongoing scientific debate. On the one hand, according to a new dendrochronological study the church was founded in no earlier than 1329. On the other hand, most scholars place the initial construction between 1310 and 1314. The designation of the church as Holy Apostles is of recent date and was said to be based on the existence of twelve vaults in the building. This popular association with the Apostles is documented in travellers’ accounts as early as 1735. The building is in a good state of preservation with much of its original construction elements intact and visible. The church’s original wall paintings and mosaics, concealed beneath a thick layer of plaster since the conversion into a mosque, were gradually uncovered and restored in various time periods, from the 1920s till 2004. 

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Capture

Image Based Structure from Motion (SfM) & Dense Multi-View 3D Reconstruction Terrestrial Laser Scanning - Time of flight. This digitisation method allowed us to e˝ciently produce high quality 3D data within the time limits introduced by the project itself. SFM-Dense Multi-View 3D Reconstruction were the main methods being used for the generation of the digital 3D replica of the model. 

Equipment Icon

Equipment

Samsung NX1000 Compact mirrorless DSLR 20MP 16mm, 20-50mm lenses Hexacopter (gimbal camera base,FPV,GPS lock) Optec Ilris 360D TOF laser scanner. 

Modelling Software

Modelling Software

Photoscan, Meshlab, Blender 

Model usU

Model Use

The data produced will be given to the monument's responsible Ephorate in order to be used for any possible internal use. A short demo of visualising the 3D model and performing measurements on its surface along with a short briefing on 3D printing technologies will be made at some point by our institution to the Ephorate's personel who were involved in the procedures of licensing us for digitising the monument. Promotion of the cultural heritage. 

Processing Pipeline

Processing Pipeline

The exterior was captured in 3D using the Structure- From-Motion (SFM) and Dense Multi-View 3D Reconstruction (DMVR) methods. Four aerial (utilising hexacopter equipped with gimbal, FPV, GPS and 2of Samsung NX1000 20MP compact DSLR cameras with ÿxed 16mm and 20-50mm lenses) and terrestrial (using 3-9m camera tripods and custom monopods, distance between capture points 60cm) photo capture sessions were performed during cloudy days. SfM processing - Agisoft PhotoScan (ver. 1.1) using a total of 4090 photos to generated the 3D model.

The processing of the image sequences was performed on two computer systems (CPU IntelCoreI74820K 3.7Ghz, 64GB RAM, Radeon R9 290X, Microsoft Windows 7 64-bit). Additionally, empirical measurements between strong (in terms of visibility) feature points on the surface of the monument were performed and used to scale the 3D model. 

Online Delivery

Online Delivery

X3DOM for lower resolutions, PLY (vertex paint) RAW The X3DOM framework o°ers a set of basic 3D viewing functions along with progressive downloading of models as well as support for the binary version of X3D reducing lower downloading times for our landing page visitor. The current version of X3DOM is supported by a wide range of Web browsers over all major OS platforms.  

http://www.ipet.gr/~akoutsou/3dicons/index.php?id= ARC3DICONS_3D_1AAP&res=L 

Licence

Licence for Dataset
Creative Commons

Creative Commons - Attribution, Non Commercial, No Derivatives.