Question

In an ideal lowpass filter case, what is the relation between the filter radius and the blurring effect caused because of the filter?

(a) Filter size is directly proportional to blurring caused because of filter

(b) Filter size is inversely proportional to blurring caused because of filter

(c) There is no relation between filter size and blurring caused because of it

(d) None of the mentioned

The question was asked in an interview for job.

This is a very interesting question from Smoothing Frequency-Domain Filters in division Intensity Transformations and Spatial Filtering of Digital Image Processing

Answer 1

Right answer is (b) Filter size is inversely proportional to blurring caused because of filter

Easiest explanation: Increase in filter size, removes less power from the image and so less severe blurring occurs.