Spectral imaging is a branch of spectroscopy

Spectroscopy

Spectroscopy is the study of the interaction between matter and radiated energy. Historically, spectroscopy originated through the study of visible light dispersed according to its wavelength, e.g., by a prism. Later the concept was expanded greatly to comprise any interaction with radiative...

 and of photography

Photography

Photography is the art, science and practice of creating durable images by recording light or other electromagnetic radiation, either electronically by means of an image sensor or chemically by means of a light-sensitive material such as photographic film...

 in which a complete spectrum

Spectrum

A spectrum is a condition that is not limited to a specific set of values but can vary infinitely within a continuum. The word saw its first scientific use within the field of optics to describe the rainbow of colors in visible light when separated using a prism; it has since been applied by...

 or some spectral information (such as the Doppler shift or Zeeman splitting of a spectral line

Spectral line

A spectral line is a dark or bright line in an otherwise uniform and continuous spectrum, resulting from a deficiency or excess of photons in a narrow frequency range, compared with the nearby frequencies.- Types of line spectra :...

) is collected at every location in an image plane

Image plane

In 3D computer graphics, the image plane is that plane in the world which is identified with the plane of the monitor. If one makes the analogy of taking a photograph to rendering a 3D image, the surface of the film is the image plane. In this case, the viewing transformation is a projection that...

. Applications include astronomy

Astronomy

Astronomy is a natural science that deals with the study of celestial objects and phenomena that originate outside the atmosphere of Earth...

, solar physics

Solar physics

For the physics journal, see Solar Physics Solar physics is the study of our Sun. It is a branch of astrophysics that specializes in exploiting and explaining the detailed measurements that are possible only for our closest star...

, analysis of plasmas

Plasma (physics)

In physics and chemistry, plasma is a state of matter similar to gas in which a certain portion of the particles are ionized. Heating a gas may ionize its molecules or atoms , thus turning it into a plasma, which contains charged particles: positive ions and negative electrons or ions...

 in nuclear fusion

Nuclear fusion

Nuclear fusion is the process by which two or more atomic nuclei join together, or "fuse", to form a single heavier nucleus. This is usually accompanied by the release or absorption of large quantities of energy...

 experiments, planetology, and Earth remote sensing

Earth remote sensing

Earth remote sensing is data collection on the environment, geology, climate, and other characteristics of the Earth by means of sensors positioned in the air or in Earth orbit. Sensors used for this type of data gathering include those covering all parts of the electromagnetic spectrum. Both...

.

Various distinctions among techniques are applied, based on criteria including spectral range, spectral resolution, number of bands, width and contiguousness of bands, and application. The terms include multispectral imaging, hyperspectral imaging

Hyperspectral imaging

Hyperspectral imaging collects and processes information from across the electromagnetic spectrum. Much as the human eye sees visible light in three bands , spectral imaging divides the spectrum into many more bands...

, full spectral imaging

Full Spectral Imaging

Full spectral imaging is a form of Imaging spectroscopy and is the successor to Hyperspectral imaging. Full Spectral Imaging was developed to improve the capabilities of Earth remote sensing . Hyperspectral imaging acquires data as many contiguous spectral bands. Full Spectral Imaging acquires...

, imaging spectroscopy

Imaging spectroscopy

Imaging spectroscopy is similar to color photography, but each pixel acquires many bands of light intensity data from the spectrum, instead of just the three bands of the RGB color model...

 or chemical imaging

Chemical imaging

Chemical imaging is the analytical capability to create a visual image of components distribution from simultaneous measurement of spectra and spatial, time informations....

. These terms are seldom applied to the use of only four or five bands that are all within the visible light range.

Spectral images are often represented as an image cube, a type of data cube

Data cube

In computer programming contexts, a data cube is a three- dimensional array of values, commonly used to describe a time series of image data...

.