Question

What is the thickness of the edges produced by first order derivatives when compared to that of second order derivatives?

(a) Finer

(b) Equal

(c) Thicker

(d) Independent

The question was asked by my school principal while I was bunking the class.

My question comes from Sharpening Spatial Filters in division Intensity Transformations and Spatial Filtering of Digital Image Processing

Answer 1

The correct choice is (c) Thicker

The explanation: We know that, the first order derivative is nonzero along the entire ramp while the second order is zero along the ramp. So, we can conclude that the first order derivatives produce thicker edges and the second order derivatives produce much finer edges.