May 21 2020
A novel technique developed by scientists employs optical coherence tomography (OCT) to capture the surface as well as the underlying details of impressionist-style oil paintings.
The researchers acquired OCT imaging data of an impressionist-style oil painting (left image). OCT images within the dotted line were digitally stitched together to produce the 3D images shown in the panels on the right. Image Credit: Yi Yang, Penn State Abington.
This data can be used for producing comprehensive three-dimensional (3D) reconstructions to improve the viewing experience and provide a way for people with vision impairments to experience paintings.
Visitors to art museums can’t closely examine paintings and see the artists’ techniques because of security and conservation concerns. Our new technology can create 3D reconstructions that can be rotated and magnified to view details such as brushstrokes. This would be especially useful for online classes.
Yi Yang, Research Team Leader, Penn State Abington
Yang and collaborators from the New Jersey Institute of Technology and Penn State University Park have reported the latest method in Applied Optics—the Optical Society (OSA) journal. Experts in art history and conservation with optical and electrical engineers were brought together by the researchers.
The novel technique integrates OCT with a mechanical scanning stage as well as novel software that enables sampling and elimination of image artifacts in real-time.
The technique involves capturing the data that can be employed to 3D print the samples so that visually impaired individuals can use their touch sensation to experience the various painting methods, like the pointillism of Seurat’s works and Van Gogh’s brushstrokes.
The ultra-high definition 3D information can also be used to repair damaged art by allowing a conservator to 3D print the damaged portion and attach it to the original painting. In addition, the imaging technique can capture high resolution details of artworks that can preserve a digital copy in case of worst-case scenarios such as war, terrorism, natural disaster, heist and other catastrophes.
Yi Yang, Research Team Leader, Penn State Abington
Making OCT Useful for Art Analysis
OCT—a laser-based non-invasive imaging method—is capable of capturing images with micrometer resolution. While this imaging technique is often used for biomedical applications, it is quite handy for art analysis because it not only captures the topographical information from the surface of a painting but also captures the structure of the underlying layers at the same time.
Because today’s OCT systems are optimized for biomedical applications, they have a limited scanning range that severely limits the speed of collecting data from large areas. We integrated a robotic scanning platform with an advanced OCT system and image processing software to capture the OCT data of paintings beyond the scanning range of typical commercial OCT systems.
Yi Yang, Research Team Leader, Penn State Abington
To boost the field of view, separate OCT images that were captured through the robotic scanner are digitally sewed together to create a bigger image. To enhance this process, the researchers created software that prevents several image artifacts, including distortions that often emerge during this kind of digital stitching.
To demonstrate their new imaging method, the scientists acquired OCT images of a part of an oil painting that imitates the exclusive impressionist-style brushstrokes and quantified 10 x 10 cm. The researchers also created a digital 3D model of the painting’s scanned area.
Now, having demonstrated the novel concept, the researchers have planned to improve their system by making enhancements in both the software and hardware.
After users create the 3D digital reconstruction of the scanned region, they can communicate with the digital 3D model to obtain a better understanding of the painting, like brushstrokes.
Journal Reference:
Zhou, X., et al. (2020) Spectral 3D reconstruction of impressionist oil paintings based on macroscopic OCT imaging. Applied Optics. doi.org/10.1364/AO.390326.