Dotted around the rugged landscape of Western Ireland and the Irish Sea are individual stones standing three or more feet out of the ground marked with symbols, mini-memorials that tell the stories of prominent people and tribes in the first language of the Irish more than 1,500 years ago.
View: Photos of the Day: Digitizing Ireland’s Ogham Inscribed Stones
Ogham stones are among Ireland’s most remarkable national treasures. These perpendicular-cut stones bear inscriptions in the unique Irish Ogham alphabet, use a system of notches and horizontal or diagonal lines/scores to represent the sounds of an early form of the Irish language. The stones are inscribed with the names of prominent people and sometimes tribal affiliation or geographical areas. These inscriptions constitute the earliest recorded form of the Irish language and, as the earliest written records dating back at least as far as the 5th century AD, are a significant resource for historians, as well as linguists and archaeologists.
3D scanning the stones in the rugged Irish landscape
Recently, many of the stones, in the ground in their many locations, were individually scanned for the sake of research and language preservation using an Artec, Eva hand-held scanner. Climbing mountains and walking through valleys, researchers carried their scanning equipment to advance the study of the Irish language; a heritage project supported by The Discovery Programme and the Dublin Institute for Advanced Studies.
According to Wikipedia: “There are roughly 400 known Ogham inscriptions on stone monuments scattered around the Irish Sea, the bulk of them dating to the 5th and 6th centuries. Their language is predominantly Primitive Irish, but a few examples record fragments of the Pictish language. Ogham itself is an Early Medieval form of alphabet or cypher, sometimes known as the “Celtic Tree Alphabet.”
Over the centuries the stones continue to weather, slowly losing their inscriptions as the elements erode the carved language and symbols. Preserving these remnants of an ancient language – and capturing the physical depth of the writing and the shape of each stone – was a perfect application for advanced, portable, hand-held 3D scanning.
Scanning the stones
The stones vary in size, with an average height of approximately 1.5m. They are often located in remote and exposed parts of Ireland which adds to the challenge of getting to them and recording their inscriptions and physical shapes in a high resolution. A small forensics tent enclosed each stone, creating a mini, controlled lighting environment and to ensure measurements could proceed whatever the weather. To ensure sufficient power for the scanner and a laptop, a portable generator was often used. Most sites are rugged and remote and a long way from a source of electricity.
Scan settings / Resolution
Technically, the scanning was undertaken with the fastest speed setting and with a minimum of 400 mm depth of field. The data from the Artec Eva scanner was recorded with sufficient overlap between scans to ensure easy registration.
Stone Models & Outputs
Post-processing was done in Artec Studio 9 software. Individual scans were edited and aligned before the final surface was generated using global registration, fusion, and a small objects filter algorithm. If required, a textured surface could also be created. To complete the project the model was exported from Artec Studio 9 as an .obj file. For the purposes of information sharing and dissemination a 3D pdf of the model is generated (using Geomagic Studio 2012) and is available to download from the project website.
3D Scanning Results
3D scanning was deemed the best method for this recording because, after 15 centuries the Ogham inscriptions have become quite subtle due to weathering. 3D data also allows for the removal of color data which could perhaps reveal inscriptions which were previously unknown or hard to decipher. The geometry of the stone is likewise important and the data will allow desktop users to take measurements of the stones while they pursue their research into the first, ancient language of the people of Ireland.
Filed Under: Rapid prototyping