Question

What is the set of pixels of 8-neighbors of pixel p at coordinates (x, y)?

(a) (x+1, y), (x-1, y), (x, y+1), (x, y-1), (x+2, y), (x-2, y), (x, y+2), (x, y-2)

(b) (x+1, y), (x-1, y), (x, y+1), (x, y-1), (x+1, y+1), (x+1, y-1), (x-1, y+1), (x-1, y-1)

(c) (x+1, y+1), (x+1, y-1), (x-1, y+1), (x-1, y-1), (x+2, y+2), (x+2, y-2), (x-2, y+2), (x-2, y-2)

(d) (x+2, y), (x-2, y), (x, y+2), (x, y-2), (x+2, y+2), (x+2, y-2), (x-2, y+2), (x-2, y-2)

This question was addressed to me in an interview.

I would like to ask this question from Relationship between Pixels and Image Enhancement Basics in section Image Enhancement of Digital Image Processing

Answer 1

Right choice is (b) (x+1, y), (x-1, y), (x, y+1), (x, y-1), (x+1, y+1), (x+1, y-1), (x-1, y+1), (x-1, y-1)

To elaborate: The set of pixels of 4-neighbors of p and Diagonal neighbors of p together are called as 8-neighbors of pixel p(x, y).