A basic overview
Here is our definition
If radiation of any kind, emitted from, or affected
by an object, causes a representation - the image - of the object
or some aspect of the object to be generated, then the systematized
body of knowledge relating to the generation, properties and processing
of the representation may be defined as Imaging Science.
Similarly, the body of knowledge relating to the practical implementation of Imaging Science may be defined as Imaging Technology.
Not just visible light
What's included according to our definition?
The term 'radiation' also refers to other phenomena in addition to light (which is just the visible part of the spectrum of electromagnetic radiation, i.e. of a relatively narrow range of wavelengths). The rest of the electromagnetic spectrum can also be included in the definition. Starting at the long-wavelength end of the range there are, in order of decreasing wavelength: radio astronomy, infra-red imaging (associated with remote sensing, aerial surveys, satellite imaging, etc.), conventional silver- halide photography and its various adjuncts (photomicrography, microphotography, astronomy, holography, graphic arts, etc.) and, at the shortest wavelengths of interest, radiography (medical and industrial x-rays).
Representation
What does that mean?
The term 'representation' is used in the definition because the idea of a picture being the image of an object is too restrictive; the more general term permits consideration of images derived from numerical data, e.g. computer generated images. So the whole gamut of digital images can be included, some examples of which are obtained without light or even a camera in the conventional sense (e.g. MRI). The terms 'generation, properties and processing' of images include a number of more familiar terms. Under the heading 'generation' might be included: display, computation, image reconstruction, etc.; under the heading 'properties', there is characteristic curve, tone scale, contrast, colour, image structure, stability, etc.; under the heading 'processing' can be included development, scanning, digitization, compression, transmission, etc.
Beyond electromagnetic
What about other radiations?
Radiation other than electromagnetic can also be included, e.g., ultrasound (used in industrial non-destructive testing as well as in medical imaging), electrons (as in electron microscopy), and a combination of magnetic and electromagnetic fields as used in magnetic resonance imaging (MRI).
In conclusion
Background to our definition
The definition of Imaging Science on which the above is based was originally drafted by Dr Arthur Saunders and used by the Science Committee for the specification of the scope of the Society Qualifications.