Terminology for an "optical RGB image" in relation to more complex imagery like hyperspectral imagery?

Solution 1:

Adding the acronym RGB doesn't help much. There are plenty of images to be found that are RGB but represent spectra we can't normally see with our unassisted eyes. Example The Horsehead Nebula in new light shows said system in the far infra-red, using RGB.

My suggestions

visible-spectrum images**

or

visible-light images**

** Of course, even these are vulnerable to criticism because different creatures see in different ranges of the spectrum. You need to make a definition of your term somewhere and then stick to it. Maybe define HVimages to mean human-vision-images.

Solution 2:

Dictionary definitions of visual relate to the seeing of something

relating to seeing

something such as a picture, photograph, or piece of film used to give a particular effect or to explain something

Cambridge dictionary

Definitions of optical relate to visual but also tend towards extra aspects relating to the use and science of light and optical science.

used in order to see something better

connected with the eyes or sight, or connected with or using light

Cambridge dictionary

of or relating to the science of optics

Merriam Webster

I therefore suggest that a layman would understand "visual image" as something to be seen with the eye, but that "optical image" would imply something about the technicalities of light, sight and optics (as does your own "optical RGB", which might even be incomprehensible to the lay person).

Furthermore, visual image is still reasonably defined within the wider spectrum of images that you are writing about so may not conflict with your technical text.