image processing MCQ’s
1) Sobel edge operator is better than prewitt edge operator in
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.
finding lines at angle 45 we use mask of values
-1 -1 -1; 2 2 2; -1 -1 -1
2 -1 -1; -1 2 -1; -1 -1 2
-1 2 -1; -1 2 -1; -1 2 -1
-1 -1 2; -1 2 -1;2 -1 -1
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
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
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
top left and right
bottom left and right
both a and b
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
cosine and sine
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
D. Histogram Specification
an image provides better contrast and a more detailed image as compare to non
transformations can be given by the expression:
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
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
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.
At second pass of histogram equalization will it differ from first pass
will already be stretched in first pass of histogram equalization thus it
doesn’t vary after second pass.