A method of imaging rock carvings in 3D using everyday electronic equipment could help document decaying carvings before they disappear forever, researchers say. Archaeologists are struggling to document many rock carvings before they are eroded by pollution or weather. Bulky laser scanners can capture detail in 3D down to 0.2 millimetres. However, such instruments are too costly and cumbersome for general use.

     A system being trialled by archaeologist Kalle Sognnes and colleagues at the Norwegian University of Science and Technology and The Foundation for Scientific and Industrial Research (SINTEF) in Trondheim provides a much simpler and cheaper solution. It consists of an ordinary office projector, a digital camera and a laptop running specially developed software. "We are trying to find something cheaper because laser scanners are so large and expensive," Sognnes said. "In some places we are coming to the end of these rock carvings, and we hope to document them before they are gone."