Question

An enhanced image can be obtained as: g(x,y)=f(x,y)-∇^2 f(x,y), where Laplacian is being subtracted from f(x, y) the input image of size M*Non which an operation f(x, y)(-1)x+yis applied.Unlike enhancing in spatial domain with one single mask, it is possible to perform the same in frequency domain using one filter. Which of the following is/are the required filter(s)?

(a) H(u, v)= -[1 + u^2+ v^2].

(b) H(u, v)= -[(u – M/2)2+ (v– N/2)2].

(c) H(u, v)= [1 + (u – M/2)2+ (v – N/2)2].

(d) All of the mentioned

I got this question in exam.

Origin of the question is Laplacian in Frequency Domain in portion Image Enhancement of Digital Image Processing

Answer 1

The correct option is (c) H(u, v)= [1 + (u – M/2)2+ (v – N/2)2].

To elaborate: The filter H(u, v)= [1 + (u – M/2)2+ (v – N/2)2] is used to perform the same enhancement in frequency domain like in spatial domain.