The expression [∂^2 f(x,y)/∂x^2 +∂^2 f(x,y)/∂y^2] is considered as _________ where f(x, y) is an input image.
(a) Laplacian of f(x, y)
(b) Gradient of f(x, y)
(c) All of the mentioned
(d) None of the mentioned
This question was addressed to me during an interview.
My question is taken from Laplacian in Frequency Domain topic in chapter Image Enhancement of Digital Image Processing