Question

Which of the following transform produces a binary image after processing?

(a) Contrast stretching

(b) Gray-level slicing

(c) All of the mentioned

(d) None of the mentioned

This question was addressed to me during a job interview.

My doubt stems from Piecewise-Linear Transformation Functions in chapter Intensity Transformations and Spatial Filtering of Digital Image Processing

Answer 1

Right option is (c) All of the mentioned

Easy explanation: The approach of gray-level slicing “to give all gray level of a specific range high value and a low value to all other gray levels” produces a binary image.

One of the transformation in Contrast stretching darkens the value of r (input image gray-level) below m (some predefined gray-value) and brightens the value of r above m, giving a binary image as result.