# Piecewise-Linear Transformation Function MCQ [Free PDF] – Objective Question Answer for Piecewise-Linear Transformation Function Quiz

1. Which gray-level transformation increases the dynamic range of gray-level in the image?

A. Power-law transformations
B. Negative transformations
C. Contrast stretching
D. None of the mentioned

Increasing the dynamic range of gray levels in the image is the basic idea behind contrast stretching.

2. When is the contrast stretching transformation a linear function, for r and s as gray-value of an image before and after processing respectively?

A. r1 = s1 and r2 = s2
B. r1 = r2, s1 = 0 and s2 = L – 1, L is the max gray value allowed
C. r1 = 1 and r2 = 0
D. None of the mentioned

If r1 = s1 and r2 = s2 the contrast stretching transformation is a linear function.

3. When is the contrast stretching transformation a thresholding function, for r and s as gray-value of an image before and after processing respectively?

A. r1 = s1 and r2 = s2
B. r1 = r2, s1 = 0 and s2 = L – 1, L is the max gray value allowed
C. r1 = 1 and r2 = 0
D. None of the mentioned

If r1 = r2, s1 = 0 and s2 = L – 1, the contrast stretching transformation is a thresholding function.

4. What condition prevents the intensity artifacts to be created while processing with contrast stretching, if r and s are gray values of the image before and after processing respectively?

A. r1 = s1 and r2 = s2
B. r1 = r2, s1 = 0 and s2 = L – 1, L is the max gray value allowed
C. r1 = 1 and r2 = 0
D. r1 ≤ r2 and s1 ≤ s2

While processing through contrast stretching, if r1 ≤ r2 and s1 ≤ s2 are maintained, the function remains single-valued and so monotonically increasing. This helps in the prevention of the creation of intensity artifacts.

5. A contrast stretching result has been obtained by setting (r1, s1) = (rmin, 0) and (r2, s2) = (rmax, L – 1), where, r and s are gray-values of the image before and after processing respectively, L is the max gray value allowed and rmax and rmin are maximum and minimum gray-values in image respectively. What should we term the transformation function if r1 = r2 = m, some mean gray-value.

A. Linear function
B. Thresholding function
C. Intermediate function
D. None of the mentioned

From (r1, s1) = (rmin, 0) and (r2, s2) = (rmax, L – 1), we have s1 = 0 and s2 = L – 1 and if r1 = r2 = m is set then the result becomes r1 = r2, s1 = 0 and s2 = L – 1, i.e. a thresholding function.

6. A specific range of gray-levels highlighting is the basic idea of __________

A. Contrast stretching
B. Bit –plane slicing
C. Thresholding
D. Gray-level slicing

gray-level slicing is being done by two approaches: One approach is to give all gray levels of a specific range high value and a low value to all other gray levels.

The second approach is to brighten the pixel’s gray value of interest and preserve the background.
I.e. in both highlighting a specific range of gray-level is been done.

7. What is/are the approach(s) of the gray-level slicing?

A. To give all gray levels of a specific range high value and a low value to all other gray levels
B. To brighten the pixel’s gray value of interest and preserve the background
C. All of the mentioned
D. None of the mentioned

There are basically two approaches to gray-level slicing:
One approach is to give all gray levels of a specific range high value and a low value to all other gray levels.
The second approach is to brighten the pixel’s gray value of interest and preserve the background.

8. 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

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

One of the transformations 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.

9. Specific bit contribution in the image highlighting is the basic idea of __________

A. Contrast stretching
B. Bit –plane slicing
C. Thresholding
D. Gray-level slicing

Bit-plane slicing highlights the contribution of specific bits made to the total image, instead of highlighting a specific gray-level range.

10. In bit-plane slicing if an image is represented by 8 bits and is composed of eight 1-bit planes, with plane 0 showing the least significant bit and plane 7 showing the most significant bit. Then, which plane(s) contain the majority of visually significant data.

A. Plane 4, 5, 6, 7
B. Plane 0, 1, 2, 3
C. Plane 0
D. Plane 2, 3, 4, 5