These beautiful crabapples are for the birds--way too bitter for humans to eat in normal circumstances.
We have a flowering crabapple tree in our back yard, and it is beautiful in the springtime. It produces tiny crabapples that the squirrels and birds share.
There was a crabapple tree in the woods where we lived when I was very young. The edible fruit it produced was much bigger than the ones in the photos, although they were still sour enough to distort your face and close your eyes at the first bite. We waited until after frost and the crabapples would turn golden. I have never seen another tree like it; I suspect it was a cross between the small crabapple trees and an apple tree from some one's orchard. We certainly enjoyed eating them, and Mama used them to make some tasty jelly.
My lil' ole sister and I were talking about that tree just the other day. We still miss it.