Library of Congress – Evaluation of the Next Generation Camera Target
Background and History
In August 2016, Avian Rochester began a second project with the Library of Congress (LC). This project follows on to the design and fabrication of the Next Generation Camera Target (NGT) with an analysis of its performance as a camera characterization target. The details of this project, entitled “Next Generation Target Evaluation,” are below.
Evaluate the effectiveness of the three color targets
The goal of the first task is to compare the NGT with other targets in common use in the museum and archiving communities. This report is largely based on a conference publication in the proceedings of IS&T’s 2017 Archivinge Conference, held in May in Riga, Latvia. (full report).
Relate the spectral sensitivities of the systems tested to the three targets
The first goal of Task B was to measure the spectral sensitivities of several available digitization systems at the Library of Congress. The spectral sensitivity is a more fundamental description of how a given system reacts to a particular wavelength of light, and how the amount of energy present at that wavelength affects the image output of the system. The second goal of Task B was to apply those spectral sensitivity properties to the spectral reflectance of the various characterization targets under consideration. By understanding the spectral properties of the targets, light source, and digitization system (as opposed to only the color coordinates) we establish a more systematic understanding of the complete imaging chain. We are now able to apply this understanding of the system properties to infer more complex underlying behaviors. (full report).
Final results of the study and future enhancements to the NGT
This report addresses the final results of the study, and suggests possible improvements in the NGT. The goal of this final part is to connect the first two, effectively comparing the theoretical and empirical camera data for the NGT and a set of common camera characterization targets. (full report).
Conclusion
The reports for this project set the stage for a more fundamental approach to imaging at the Library of Congress. Namely, the application of a spectral imaging workflow.