Question

If r be the gray-level of image before processing and s after processing then which expression helps to obtain the negative of an image for the gray-level in the range [0, L-1]?

(a) s = L – 1 – r

(b) s = crᵞ, c and ᵞ are positive constants

(c) s = c log (1 + r), c is a constant and r ≥ 0

(d) none of the mentioned

This question was addressed to me by my college professor while I was bunking the class.

I want to ask this question from Basic Grey Level Transformation in section Image Enhancement of Digital Image Processing

Answer 1

The correct answer is (c) s = c log (1 + r), c is a constant and r ≥ 0

The explanation is: The expression for log transformation is given as: s = c log (1 + r), c is a constant and r ≥ 0.