Case in point:
Personally, I'd recommend a deletion of the "unnamed" user with pointing out that multi-usering is discouraged, but I don't know policy on that.
EDIT: Ah, Meta.SE says that accounts can be merged, so this now becomes a merge request, unless Man engaged in "sockpuppeteering" (i.e. using user46417 to upvote himself).
EDIT2: The edit history of Difference between repeated poles and non repeated poles? might suggest that also abjt and Man are the same person, although it's not that conclusive; abjt might simply have been sitting next to Man and overly eagerly tried to specify Man's question and changed directions of the question in the process. I'll simply ask.
EDIT3: OK, this is starting to feel like a conspiracy theory, but engr's Image processing vs signal processing? is, especially in the final sentence, so much like image processing vs Computer vision? that it defies the feeling of a likely coincidence.