Question

The transfer function of High frequency emphasis is given as: Hhfe(u, v) = a + b Hhp(u, v), for Hhp(u, v) being the highpass filtered version of image,a≥0 and b>a. for certain values of a and b it reduces to High-boost filtering. Which of the following is the required value?

(a) a = (A-1) and b = 0,A is some constant

(b) a = 0 and b = (A-1),A is some constant

(c) a = 1 and b = 1

(d) a = (A-1) and b =1,A is some constant

This question was posed to me in a national level competition.

I want to ask this question from Unsharp Masking, High-boost filtering and Emphasis Filtering in division Intensity Transformations and Spatial Filtering of Digital Image Processing

Answer 1

The correct option is (d) a = (A-1) and b =1,A is some constant

Easiest explanation: The transfer function of High frequency emphasis is given as: Hhfe(u, v) = a + b Hhp(u, v) and the transfer function for High-boost filtering is Hhb(u, v) = (A-1) + Hhp(u, v), A being some constant. So, for a = (A-1) and b =1, Hhfe(u, v) = Hhb(u, v).