visual image vs visualisation

visual image and visualisation both are nouns.

Word	Noun	Adjective	Verb	Adverb
visual image	Yes	No	No	No
visualisation	Yes	No	No	No

As nouns, visual image and visualisation are synonyms defined as:

visual image and visualisation: a mental image that is similar to a visual perception

Other synonyms of visual image include visualization.

visual image (noun)	visualisation (noun)
a percept that arises from the eyes; an image in the visual system	a mental image that is similar to a visual perception
a mental image that is similar to a visual perception