(11-Mar-2011) CIS Professor on Taiwan Tour

Dr Roy Berns, CIS Professor and Director of the Munsell Color Science Laboratory, is on a four-day trip to Taiwan including several technical presentations. These are summarized below The first three talks were for the TELDAP Workshop on Digitalization Workflow Guidelines. The final presentation was for the Color Association of Taiwan and CIE-Taiwan.

Image Capture Minimizing Visual Editing–An Update From The 2005 American Benchmarking Project
TELDAP Workshop on Digitalization Workflow Guidelines

In 2005, RIT published a report, “Direct Digital Capture of Cultural Heritage – Benchmarking American Museum Practices and Defining Future Needs.” Sponsored by the Andrew W. Mellon Foundation, there were 14 key findings and 9 suggestions for future research. Currently, this evaluation is being repeated and extended by including visual evaluations where all images are printed using a single, highly calibrated printer. In both studies, the color accuracy achieved within museum imaging departments, in general, is poorer than that achievable by university research groups. It is important to point out that most museums include visual editing in their workflow while academia does not. However, even when a camera has nearly perfect color accuracy, the image may still mismatch the artwork when viewed adjacently, requiring a tonal adjustment. This presentation will include a review of 2005 study, results from the current study, and current approaches developed in the Munsell Color Science Laboratory for image capture that minimize the need for visual editing in the workflow.

Turning back the ravages of time: Color reconstructions of Seurat and van Gogh paintings and drawings using color and imaging sciences

For some paintings and drawings, their color appearance today bears little resemblance to that achieved at the time of their execution. Red and yellow lakes may fade away; copper resinates may turn from green to brown; paper may brown. In some cases, the color changes are gradual, occurring over a period of centuries. In other cases, the color changes are dramatic, occurring over a period of years. For example, the zinc-yellow paint used by Georges Seurat in Bathers at Asnieres and in A Sunday on La Grande Jatte – 1884 changed his divisionist dabs of bright yellow and green to dull brown and olive. Recent advances in digital imaging and the use of spectrophotometry-based color mixing optics enables image simulations that turn back the ravages of time. This talk will describe research by the author in collaboration with museum conservators and curators in creating color reconstructions of La Grande Jatte (Art Institute of Chicago) and paintings and drawings by Vincent van Gogh including The Bedroom (Van Gogh Museum).

Three-Dimensional Multi-Spectral Imaging of Artwork

During 2001, a research program was initiated at RIT’s Munsell Color Science Laboratory (MCSL) to develop a practical workflow to facilitate image capture, archiving, and printing without the need for visual editing and without limiting viewing conditions to a single reference light (i.e., D50). This required expanding the three-channel ICC profile connection space (PCS) to a multi-channel space that encodes spectral information. This approach, while still within the domain of academia, has captured the attention of the ICC such that a companion workflow is under development, ICC.2, which will include a spectral-based PCS. Perhaps the key element is the ability to capture spectral images and many approaches have been implemented, internationally. At MCSL, we developed a camera that uses any RGB area-array sensor and a pair of custom filters placed sequentially in the optical path. The pair of RGB images are combined during the calibration stage producing both color-accurate profiled RGB tiff files (for use in the current ICC.1) workflow and spectral images (for the future ICC.2 workflow). Beginning in 2009, the research program was expanded to include 3-D imaging of artwork that additionally captures spatially varying surface normal and bi-directional reflectance distribution functions (BRDF). Combined with computer-graphics rendering, a virtual museum can be created to display a collection as well as produce color-managed images where lighting decisions are determined interactively rather than pre-defined during image capture. This presentation will describe this approach to three-dimensional multi-spectral imaging of artwork.

The RIT Munsell Color Science Laboratory: An International Resource for Color and Imaging Science Research, Education, and Outreach

The Munsell Color Science Laboratory was founded in 1983 with a mission to advance the science, understanding, and technology of color and appearance through education, research, and outreach. As a laboratory within the Chester F. Carlson Center for Imaging Science, its research encompasses both traditional color science and image-based fundamental and applied topics. These include: 1) Colorimetry including metrology, psychophysics, and tolerance formulae modeling, 2) Image color-appearance psychophysics and modeling, 3) High-dynamic range image capture and display, 4) 3-D imaging of paintings including BRDF, surface-normal, and visible-spectral measurements and realistic image synthesis, 5) Spectral color reproduction including multi-spectral capture, multi-ink inkjet printing, and spectral color management, 6) Art conservation science, 7) Material appearance, 8) Computational photography. This presentation will be an overview of the Laboratory’s current faculty, students, and research programs.

Biography: Dr. Roy S. Berns is the Richard S. Hunter Professor in Color Science, Appearance, and Technology and Director of the Munsell Color Science Laboratory within the Center for Imaging Science at Rochester Institute of Technology, USA. He received B.S. and M.S. degrees in Textiles from the University of California at Davis and a Ph.D. degree in Chemistry from Rensselaer Polytechnic Institute (RPI). Berns has received scientific achievement awards from the Inter-Society Color Council, the Society of Imaging Science and Technology, and the Colour Group of Great Britain. He is the author of the third edition of “Billmeyer and Saltzman’s Principles of Color Technology,” and an author of over 200 publications. Berns’ main research focus is using color and imaging sciences for the visual arts, particularly paintings, including: 3-D imaging and computer-graphics rendering; spectral-based imaging, archiving, and reproduction; pigment mapping; visible-fluorescence imaging, colorant selection for inpainting, digital rejuvenation, and image rendering as a function of object and reproduction sizes.