percept vs visual image

percept and visual image both are nouns.

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

As nouns, visual image is a hyponym of percept; that is, visual image is a word with a more specific, narrower meaning than percept:

percept: the representation of what is perceived; basic component in the formation of a concept
visual image: a percept that arises from the eyes; an image in the visual system

Other hyponyms of percept include figure, ground, visual percept.

percept (noun)	visual image (noun)
the representation of what is perceived; basic component in the formation of a concept	a percept that arises from the eyes; an image in the visual system
	a mental image that is similar to a visual perception