Which of the following filter(s) attenuates low frequency while passing high frequencies of an image?
(a) Unsharp mask filter
(b) Highpass filter
(c) Zero-phase-shift filter
(d) All of the mentioned
I had been asked this question in a job interview.
The origin of the question is Filtering in Frequency Domain topic in division Intensity Transformations and Spatial Filtering of Digital Image Processing