Question

Which of the following fact(s) is/are true about sharpening spatial filters using digital differentiation?

(a) Sharpening spatial filter response is proportional to the discontinuity of the image at the point where the derivative operation is applied

(b) Sharpening spatial filters enhances edges and discontinuities like noise

(c) Sharpening spatial filters deemphasizes areas that have slowly varying gray-level values

(d) All of the mentioned

I had been asked this question by my college professor while I was bunking the class.

My doubt stems from Sharpening Spatial Filters-2 in division Intensity Transformations and Spatial Filtering of Digital Image Processing

Answer 1

Correct answer is (d) All of the mentioned

Easiest explanation: Derivative operator’s response is proportional to the discontinuity of the image at the point where the derivative operation is applied.

Image differentiation enhances edges and discontinuities like noise and deemphasizes areas that have slowly varying gray-level values.

Since a sharpening spatial filters are analogous to differentiation, so, all the above mentioned facts are true for sharpening spatial filters.