Question

Which of the following is/ are a generalized form of unsharp masking?

(a) Lowpass filtering

(b) High-boost filtering

(c) Emphasis filtering

(d) All of the mentioned

The question was asked in an international level competition.

Question is from Unsharp Masking, High-boost filtering and Emphasis Filtering topic in portion Intensity Transformations and Spatial Filtering of Digital Image Processing

Answer 1

Right answer is (b) High-boost filtering

To elaborate: Unsharp masking is defined as “obtaining a highpass filtered image by subtracting from the given image a lowpass filtered version of itself” while high-boost filtering generalizes it by multiplying the input image by a constant, say A≥1.