dreaming vs imaging

dreaming and imaging both are nouns.

Word	Noun	Adjective	Verb	Adverb
dreaming	Yes	No	No	No
imaging	Yes	No	No	No

As nouns, imaging is a hypernym of dreaming; that is, imaging is a word with a broader meaning than dreaming:

Other hypernyms of dreaming include imagery, imagination, mental imagery.

dreaming (noun)	imaging (noun)
a series of mental images and emotions occurring during sleep	(medicine) obtaining pictures of the interior of the body
imaginative thoughts indulged in while awake	the ability to form mental images of things or events