Digital Image Processing- MCQ2

1. Digital Image Processing
Multiple Choice Questions
1. Calculate the resolution of the image of size 1024 x 1024 (L2)
a) 1048576
b) 1148576
c) 1248576
d) 1348576
Answer: 1048576
2. Assume that a 10 m high structure is observed at a distance of 50m. What is the
size of the retinal image? (L3)
a) 8.6 mm
b) 5.7 mm
c) 2.5 mm
d) 3.4 mm
Ans: 3.4 mm
3. Estimate the storage requirement for a 1024X1024 24-bit colour image. (L3)
a) 2146.745 Kb
b) 3145.728 Kb
c) 3142.645 Kb
d) 2416.455 Kb
Answer: 3145.728 Kb
4.Estimate the storage requirement for a 1024X1024 24-binary image. (L3)
a) 141.065 Kb
b) 138.042 Kb
c) 131.072 Kb
d)147.042 Kb
Answer: 131.072 Kb
5.What is the storage requirement of 1024 x 1024, 8-level grey level image? (L3)
a) 1024.756 Kb
b) 1048.576 Kb
c) 512.24 Kb
d) 864.78 Kb
Answer: 1048.576 Kb
6.Consider a color 1024 x 1024 image. If this image is transmitted across a channel of 2
Mbps, what will be the transmission time? (L3)

2. a) 8.59 seconds
b) 16.46 seconds
c) 12.58 seconds
d) 14.82 seconds
Answer: 12.58 seconds.
7.A picture of physical size 2.5 inches by 2 inches is scanned at 150 dpi.How many pixels
would be there in the image? (L3)
a)102344 pixels
b)112500 pixels
c)177822 pixels
d)102933 pixels
Ans:112500 pixels
8. If a 375 X 300 grey-scale image needs to be sent across the channel of capacity 28
Kbps,than how much transmission time is required. (L3)
a)22.343 sec
b)35.754 sec
c)32.143 sec
d)43.613 sec
Ans: 32.143 sec
9. An object is 15cm wide and is imaged with a sensor of size 8.8 x 6.6 mm2 from a
distance of 7 m. What should be the required focal length? (L3)
a) 16.64 mm
b) 12.64 mm
c) 38.81 mm
d) 48.24 mm
Ans: 38.81mm
10. Assume that a 20m high structure is observed at a distance of 25m. What is the size of
the retinal image? (L3)
a) 13.6 mm
b) 15.7 mm
c) 12.5 mm
d) 16.4 mm
Ans: 13.6 mm
11. Consider a grey scale image whose physical dimension is 5 inchs X 6 inches
scanned at the rate of 300 dpi. Calculate the following:
(i) Number of bits required to represent the image.
(ii) Time required to transmit the image if modem is 28 kbps.
(iii) Estimate (i) and (ii) if it were a binary image. (L3)
a) 8000000 bits, 112.14s, 114500 bits, 3.017s
b) 7600000 bits, 416.12s, 124500 bits, 6.015s
c) 6750000 bits, 624.14s, 112460 bits, 55.027s
d) 21600000 bits, 771.43 sec,2700000 bits, 96.429 sec
Ans: 21600000 bits, 771.43 sec,2700000 bits, 96.429 sec

3. 12. Let the height of a structure is 10m. If it is observed from a height of 50 m what is
the height of retinal image (L3)
a) 2.5 mm
b) 3.8 mm
c) 3.4 mm
d) 2.9 mm
Ans: 3.4 mm
13. The width of an object is 15 cm and is imaged with a sensor of sixe 8.8 X 6.6
mm2 from a distance of 7m. Calculate the required focal length. (L2)
a) 32.42 mm
b) 24.12 mm
c) 38.81 mm
d) 46.26 mm
Ans: 38.81 mm
14. If the background and foreground intensity of an image is 50 and 100 respectively,
what would be the simultaneous contrast. If the background is changed to 120,
what would be the contrast. (L3)
a) 0.875, -0.167
b) 1, -0.167
c) -0.156, 0.342
d) 1, 0.342
Ans: 1, -0.167
15. Consider a grey scale image whose physical dimension is 2.5 inch X 2 inch,
scanned at the rate of 150 dpi. Calculate the following:
(i) Number of bits required to represent the image.
(ii) Time required to transmit the image if modem is 28 kbps.
(iii) Estimate (i) and (ii) if it were a binary image. (L3)
a) 800000 bits, 12.14s, 114500 bits, 3.017s
b) 760000 bits, 46.12s, 124500 bits, 6.015s
c) 675000 bits, 64.14s, 112460 bits, 55.027s
d) 900000 bits, 32.14s, 112500 bits, 4.017s
Ans: 900000 bits, 32.14s, 112500 bits, 4.017s
16. An object is 20cm wide and is imaged with a sensor of size 8.8 x 6.6 mm2 from a
distance of 0.3m. What should be the required focal length? (L3)
a) 16.64 mm
b) 12.64 mm
c) 64.12 mm
d) 48.24 mm
Ans: 12.64 mm
17. The digital image f(x,y) with U rows and V columns needs decisions about values
for U,V with the maximum gray levels ‘L’ for each pixel is integer power of 2. If
we assume that the discrete levels are integer with equally spaced then the
intervals is ________ and range of values spanned by gray scale is ______ of an
image. (L2)

4. a) [0, L – 1] and static range respectively
b) [0, L / 2] and static range respectively
c) [0, L / 2] and dynamic range respectively
d) [0, L – 1] and dynamic range respectively
Answer: [0, L – 1] and dynamic range respectively
18. Consider an image f(x,y) which has U rows and V columns after sampling. What
would be the notation(0,1) signifies if the values of the coordinates at the origin
are (x,y)=(0,0). (L2)
a) Second sample along first row
b) First sample along first row
c) First sample along second row
d) Second sample along second row
Answer: Second sample along first row.
19. Validate the statement “The image have high contrast when it has an appreciable
number of pixels with high dynamic range”. (L2)
a) True
b) False
Answer : True
20. For an image f(x,y) =R1{3 2 1},R2{1 2 1},R3{3 2 2} and f’(x,y)=R1{3 1 1},
R2{1 1 2}, R3{1 1 1}. Compute Signal-to-noise Ratio (L3)
a) 8.8
b) 4.7
c) 12.8
d) 4.6
Ans: 12.8