WHAT HYPERSPECTRAL IMAGING PROVIDES?

This tutorial will introduce what kinds of data hyperspectral imaging provides. As shown in the previous tutorial, a hyperspectral camera is used to collect a data cube. In our example, we compared the data cube to a book. Let’s discover how this differs from the data and images from other types of cameras.

Digital or smartphone camera shoots the target in three colors red, green, and blue to match the human vision. These colors, which are broad wavelength channels, are equal to the amount of information that is recorded and the book will have. The result is a small book or leaflet with three pages. The color image we can see with our eyes is the combination of the pages we see on the cover. With a hyperspectral camera, our target is recorded from tens to hundreds of narrow color channels, meaning wavelengths.

The amount of wavelengths depends on what type of hyperspectral camera is used. In this example, the target is recorded in 220 wavelengths throughout the target area. Again, this is the amount of information that our book will have. Every wavelength is presented as a page of the book. As you compared to the previous, this book is much bigger and contains much more detailed information about our target. In most cases, a hyperspectral camera collects information from the wavelengths invisible to human vision.

The book cover that we see is constructed from many wavelengths. As said, every page of the book presents its own information. By combining different pages, we can process different qualities of our target, such as possible plant diseases that are infecting the leaf or the amount of water the leaf contains.

We are also able to choose any point of the leaf from the book cover and obtain its full, accurate, and continuous spectrum. This requires that we use all the information on that specific point on every page of the book. We sort of drill a slice of the entire book to get spectral information. So, the hyperspectral camera measures the target in every wavelength that is located, and the hyperspectral camera’s spectral range creates a full spectrum for each pixel of the target.

The collected full spectral information is versatile for analysis, detection, and identification of various materials and compounds, and all with just one measurement.