Digital

image processing MCQ’s

1) Sobel edge operator is better than prewitt edge operator in

image for

A.

blurring

B.

contrast

C.

sharpening

D.

smoothing

Solution: D

As, It operates after eliminating spurious edges

((i.e.) edges will not be connected after applying this filter) due to noise

and hence gives a clear and thick boundary.

2) For

finding lines at angle 45 we use mask of values

A.

-1 -1 -1; 2 2 2; -1 -1 -1

B.

2 -1 -1; -1 2 -1; -1 -1 2

C.

-1 2 -1; -1 2 -1; -1 2 -1

D.

-1 -1 2; -1 2 -1;2 -1 -1

Solution:

B

As,

it has to find lines at angle 45 the weight of pixels in filter matrix along

anti-diagonal should be high when compared with forward diagonal.

3) Bit plane slicing is used in

A.

aortic angiogram

B.

radar

C.

contrast stretching

D.

MRI

Solution:

A

Aortic

angiography, or an angiogram, is a procedure to test for defects and

functional problems in your aorta, your largest artery. As it deals with

largest artery informations about smaller arteries don’t matter. Thus lower

planes can be eliminated which could help in image storage and transfer as

lesser bites would be required to store these images.

4) In contrast

stretching of image if slope is less than 1 resulting image is

A.

relatively dark

B.

relatively light

C.

fully dark

D.

fully light

Solution:

A

As slope is less than 1, dynamic range reduces hence image

produces a relatively dark image.

5) Fast fourier transformation has low frequency regions at

A.

top left and right

corner

B.

bottom left and right

corner

C.

both a and b

D.

none

Solution: C

In fast fourier transform lower frequency

regions are present at top left and right corner, bottom left and right corner

and higher frequency region at the centre or transformed image.

6) The haar, walsh and hadamard transforms are

___________in nature.

A.

sinusoidal

B.

cosine

C.

non-sinusoidal

D.

cosine and sine

Solution: C

As, these transforms don’t operate on sinusoidal

waves. Non-sinusoidal waveforms are

waveforms that are not pure sin waves.

7) Dark characteristics

in an image are better solved using

A. Laplacian Transform

B. Gaussian Transform

C. Power-law

Transformation

D. Histogram Specification

Solution:

C

Enhancing

an image provides better contrast and a more detailed image as compare to non

enhanced image.

These

transformations can be given by the expression:

s=Cr^?

where,

C constant C>1

r intensity of pixel

? is called gamma, due

to which this transformation is also known as gamma transformation.

Variation in the value

of ? varies the enhancement of the images.

8) Number of huffman codes available for coding

3 symbols.

A.

1

B.

2

C.

3

D.

4

Solution:

B

Codes

could be 0,10,11 or 1,00,01. depending on whether the subtree is placed on left

or right of the main tree.

9) Canny edge detection algorithm is based on

A.

ideal model

B.

step edge

C.

real model

D.

smoothing model

Solution: B

The Canny edge detector is

an edge detection operator that uses a multi-stage algorithm to

detect a wide range of edges in images. It is a

technique to extract useful structural information from different vision

objects and dramatically reduce the amount of data to be processed.

10)

At second pass of histogram equalization will it differ from first pass

A.

no

B.

yes

C.

may be

D.

none

Solution:

A

Histogram

will already be stretched in first pass of histogram equalization thus it

doesn’t vary after second pass.