Infrared Imaging of Artwork for Analysis and Restoration

In art history and restoration technology, infrared analysis has been applied to assess the physical state of a painting, and to determine the existence of underdrawings or over-paintings.

Infrared imaging  provides a convenient as well as non-destructive way of visualizing the underdrawings due to the low infrared absorption in the top paint layers.  This allows explore the underlying structures, outlines and earlier versions.

Infrared Imaging in Artwork Analysis

Underdrawings can be observed on several paintings from every era. They are initial sketches which still exist underneath the paint layers, and can be visualized by means of IR-reflectography (Figure 1) (imaging in the short wave infrared). They are usually drawn with pencil, charcoal, or brushstrokes, and are usually covered completely by the later layers of paint.

Figure 1. Scetches lying under the paint layers are made visible using IR-reflectography

Every artist has his own style and method of underdrawings, from simple outlines to detailed sketches. Hence, details about the creative work process of a painter can be obtained from the underdrawing.

With advances in modern IR techniques and instruments, it is now possible to improve the cost-efficiency of this technique, making it more widely available. More sophisticated imaging applications can also be investigated.

Xenics’ Infrared Solutions

For this application, Xenics offers the following infrared cameras:

• Bobcat-320-Star is a limited edition SWIR camera based on Xenics’ Bobcat-1.7-320 in a very compact housing
• Xeva-1.7-320 is for advanced research in SWIR imaging, with spectrograph compatibility and high sensitivity for low light conditions
• Xeva-1.7-640 is for advanced research in SWIR imaging, with superior low dark current and low-noise imaging
• Xeva-2.5-320 is a flexible SWIR imaging camera of up to 2.5µm, with the smallest TE4-cooled camera suitable for scientific image recording and analysis

About Xenics

Xenics is a well established and rapidly growing high-tech company about to enter exciting new fields of IR products and applications, serving the markets with excellent products and a strong technology background. This enables us to do custom designed chips and add functionality as requested, such as specific read-out capability.

Uncooled InGaAs-based devices will revolutionize the global markets for short wave infrared spectroscopy, imaging and non-contact temperature measurement. Uncooled bolometer-based products will revolutionize the markets for thermal imaging and thermography. While advanced cooled products will continue to grow in the markets that require the ultimate performance level or specialty features.

You will see many exciting new applications – commercial, industrial, medical, security-related, scientific, and many others - over the coming years. That's exactly where Xenics is positioned. Thus, Xenics will play a leading role in developing these exciting markets.

Xenics offers products covering the most active IR wavelength areas from 1 up to 14 micrometer. They come as line-scan as well as two-dimensional devices. Xenics also delivers custom detectors, cameras or electro-optic instrumentation solutions according to our customers' agreed specifications and project setups.

This information has been sourced, reviewed and adapted from materials provided by Xenics.

For more information on this source, please visit Xenics.