Cyber Tools to Aid Understanding of the Medieval French Book Trade
Cyber Connoisseurship
The Art History, French and Medieval Studies programs at the University of Illinois are working together with NCSA to develop cyber tools for analyzing the visual imagery embedded in several early manuscripts of Jean Froissart's Chronicles, which have been successfully digitalized and mounted on the web and are available through Virtual Vellum (see also Virtual Vellum Overview). With the collaboration of a team at the University of Illinois and several European institutions, they plan to develop cyber tools for analyzing the visual imagery embedded in manuscripts.
Art historians have long used the practice of connoisseurship (a careful visual examination of a given work) to identify artistic hands. A central tenet of the approach is the assumption that, while artists might vary their general compositions, they will always consistently draw or paint routine elements, such as ears, eyes, hands, and drapery. The tools developed will aid this endeavor by sorting large collections of data and running comparisons of brushstrokes and colors, thus making it easier to differentiate between artists working in a similar style.
We use the term Cyber connoisseurship in a narrow view for understanding through digital techniques and tools of how artistic practice worked among manuscript producers in the late Middle Ages.
Our goal is to provide insight into both the construction of these specific Froissart manuscripts, and more broadly, the functioning of the medieval Parisian book trade. Through computer analysis of manuscripts and sorting of artistic hands, art historians will gain and an understanding of how groups of artists collaborated to create manuscript illuminations. They will be able to identify artists that work together on a single project and groups that work in different combinations on several projects. The tools developed will be available on a website shared by NCSA and Medieval Studies at the University of Illinois, with Virtual Vellum at the University of Sheffield, UK, and with the Worldwide Universities Network, so that they may be applied to other families of manuscripts.
Figures below illustrate the first results obtained by analyzing Besancon and Brussels manuscripts using Image registration tool.
Figure 1. Left: Comparison of multiple zoomed regions from two manuscripts as shown in Virtual Vellum viewer. Right: View of the Image registration tool. The fiducial marks on the two images were used as control pairs of points for computing the affine transformation registration parameters.
Figure 2. Result of registration as an overlay of two illustrations sub-areas (with faces).
The result is shown in Figure 2 as a sequence of two image overlays with variable transparency (0, 50 and 100% transparency of the right image on the left image) as indicated by the slider bar on the bottom of each window. The user driven change of transparency parameter allows not only exploring the visual differences in the crown and the color pattern of the cloth but also quantifying the scaling offset of the mouth by each artist. The right image in Figure 2 was obtained by subtracting the registered images.
Acknowledgments
This project has been funded by NCSA and NSF. We would like to acknowledge the NCSA Faculty Fellow program and the NSF ITS 09-10562 EAGER program for
providing the funding.
University of Illinois
