Hyperspectral Imaging and its Applications

What do bruised fruit, the United States of America’s Declaration of Independence and crime scenes have in common? Our understanding of them has all been enhanced by the use of hyperspectral imaging.

Hyperspectral imaging cameras can determine if objects being viewed are hot or cold, wet or dry, their fat and sugar content and the presence of certain chemical elements. Therefore, it has a diverse range of applications in areas such as pharmaceuticals, food technology and homeland security. Whereas conventional colour cameras capture light in just three spectral windows, hyperspectral cameras have the ability to capture an entire section of the electromagnetic spectrum at every pixel. There are a number of different techniques for hyperspectral image capture including pushbroom and optically tuned filters. New capture techniques are also being developed.

In the past hyperspectral cameras were bulky and expensive and so were mostly used by the military for remote sensing and surveillance applications. Today’s hyperspectral cameras are almost as small as a standard video camera. These latest developments in camera technology are moving hyperspectral imaging from the aircraft and the military surveillance station to the laboratory and the production line.

The astonishing range of industries where these laboratories and factories are based emphasises the relevance and importance of the growth of hyperspectral imaging technology.

In agriculture hyperspectral imaging can be used to determine if soft fruit, such as apples, are bruised below the surface and likely to have a short shelf life. Similarly, HSI technology can be used in Biomedical Engineering to reveal the extent of burns and bruises below the skin of the human body.

Hyperspectral imaging is playing an increasingly important role in forensic technologies. The detection of fingerprints at crime scenes and the analysis of inks to detect forged documents can all be carried out using the technology. Hyperspectral imaging has even helped to bring new insights to old documents. The Library of Congress’ Preservation Research and Testing Division has carried out work on discarded drafts of the American Declaration of Independence to uncover crossed out words. This research has helped to give modern historians a deeper understanding into Thomas Jefferson’s thought process.

As hyperspectral imaging generates an entire section of the electromagnetic spectrum in real time for every pixel of an image, the sheer volume of data it produces can be enormous. Therefore, it requires large data storage and throughput; efficient data reduction algorithms; and intelligent and selective image capture to develop a complete system.

In general, the end user in a laboratory or factory only need a standalone turnkey system to solve a particular problem, such as whether a pharmaceutical product is counterfeit or the extent of bruising in the fruit. Such systems require new and state of the art image processing algorithms to reach correct decisions in real time.

The keynote will give an overview of Hyperspectral Imaging technology and its applications to information-processing tasks.