Multispectral Imaging for Palimpsests (1h)

This lesson focuses on the application of multispectral imaging to analyze palimpsests. Participants will learn how to enhance the readability of faded carbon black ink while minimizing the visibility of iron gall ink through the use of selective spectral filters. Objectives

• Understand the principles of multispectral imaging.
• Learn how to use spectral filters to isolate carbon-based ink.
• Explore the process of building a multispectral cube for enhanced image analysis.

Materials

• Antonello, multispectral imaging system with 18 spectral filters.
• Modified digital camera for Technical Photography.
• Mock-up palimpsest.

Lesson Plan

1. Introduction to Multispectral Imaging
   • Explanation of Antonello multispectral imaging system.
   • Review of reflectance spectra for support, iron gall ink, and carbon black ink.
2. Filter Selection
   • Selection of three key filters based on reflectance spectra (450 nm, 671 nm, and 920 nm).
3. Building the Multispectral Cube
   • Demonstration of loading spectral images into the software.
   • Step-by-step process for selecting carbon ink points and applying classification algorithms.
4. Image Classification and Enhancement
   • Using Euclidean distance to classify carbon ink.
   • Adjusting tolerance to optimize visibility of the faded text.