UV Imaging System for Discovering Hidden Text

Side-by-side photos of RIT students and activities with the text See How RIT is Advancing the Exceptional underneath.

Freshman students spent over a year making a system to reveal hidden text on medieval manuscripts called palimpsests. Palimpsests are parchment documents that had text scraped off or chemically removed and were subsequently written over. The UV Multispectral Imaging System the students created reveals and images this removed text. The students have used the system to discover many palimpsests in RIT's own Cary Collection.

The system works by illuminating documents with a black light, causing them to glow and revealing hidden text. The system then takes an image of the hidden text. The readability of the hidden text is improved by placing colored filters in front of the camera, limiting what colors of light enter the camera.

The entire capturing process was coded in Python to be automated. After a few clicks, the system takes pictures with different filters and lighting conditions without any further input from the user.

Python was also used to make a GUI that allows the user to easily modify the images to increase the readability of the undertext. Methods to increase readability include sharpness and principal component analysis.

Two palimpsests from the Otto Ege collection were discovered in RIT's Cary Collection, including a leaf from a French Book of Hours. The leaf previously had French cursive that was removed before it became part of the Book of Hours.

Two students testing the imaging system by making fake palimpsests with highlighters.

Comparison of a palimpsest imaged in white light and in color (left), and using the UV lights and grey scale camera on the imaging system (right). The image on the right shows French cursive that was removed and written over 500 years ago.

This images shows the easy to use image enhancement user interface that is built in to the imaging system. It is used to modify the images taken with the system, making them easier to read.

On the left is an image of a palimpsest imaged in white light. On the right is an image of the same palimpsest taken under UV light and after image enhancement methods were preformed. The image on the right shows white text that was removed hundreds of years ago, and was written over.

Student placing a glowing filter in to the imaging system's filter wheel.

Malcolm Zale, Lisa Enochs and Zoe LaLena are pictured form left to right. Each of these students developed the imaging system and made miraculous discoveries over the past year.


Zoe LaLena,
Lisa Enochs,
Malcolm Zale,
Elizabeth Del Vecchio,
Karen Braun

Karen Braun

Extended Innovative Freshman Experience

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