When most people hear the term “3D” they typically think of movies, video games or other forms of media which intend to enhance a viewing experience. For Blazie Professor of Electrical Engineering Dr. Laurence Hassebrook, three-dimensional technology offers possibilities for archeological research previously unavailable to scientists, historians and anthropologists. Over 30 years of research into Structured Light Illumination (SLI) has contributed to breakthroughs in the quality of 3D scans, and led him to test his innovative devices in extreme locations!
Dr. Hassebrook describes SLI as, “like seeing the light pattern from a Venetian blind across a room. The stripes look crooked because your eyes (or for our purposes, the camera) are at a different angle than the sun shining through (or, our projection angle). The crooked or distorted shape yields the depth when we apply geometry to the triangulation between the eye and the projected light pattern. We use much more sophisticated patterns and even sequences of patterns to help decode the depth most accurately.”
Progressive research into SLI techniques has allowed Dr. Hassebrook to gather 3D data in unexpected places. In 2009, he and graduate research assistant Eli Crane constructed a remote “Rotate and Hold and Scan” (RAHAS) device capable scanning artifacts which cannot be removed for laboratory examination. To test the portable scanner, Crane and Dr. Chris Begley of Transylvania University traveled to the rain forests of Honduras, where they scanned petroglyphs carved into rocks over 500 years ago. Because of water erosion, many of the carvings were difficult to distinguish; however, the RAHAS prototype allowed Crane and Begley to obtain detailed 3D data on the petroglyphs for later analysis.
Later that year, Dr. Hassebrook, Dr. Begley and team visited a historic Lexington graveyard with a different prototype to scan headstones largely illegible to the naked eye. Some headstones were over 150 years old and the engraved information had virtually eroded over time. The scanner provided crucial 3-D images, offering Dr. Hassebrook and his team a clear picture of what was written on the headstones. In one case, although the team determined the death date on a particular headstone was 1818, the 3-D image presented by the scanner revealed a thinly engraved line which rendered the actual death date as 1848!
Dr. Hassebrook’s recent travels involved returning to Honduras to scan more petroglyphs, followed by trips to Spain and Sicily to scan artifacts ranging from coins and rings to a Phoenician nautical weapon called a ram. The success of this technology continues to create opportunities for Dr. Hassebrook and his team to amass information on previously unstudied relics.
Although Dr. Hassebrook’s exciting research is branching out into new areas, such as the fashion and clothing industry through a partnership between the University of Kentucky Center for Visualization and Virtual Environments and the Lexington Fashion Collaborative, he still enjoys the interaction with students in the classroom and in the lab. “Everything I do is dependent on other people and their abilities,” he says. “In a sense, teaching is part of that ‘pass it on’ process. But I think the most fun is when I give the students open-ended projects and they come back with approaches and ideas I did not expect or even know about.”