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September 2024 term · Deep Learning for Computer Vision · BSDA5006

Deep Learning for Computer Vision Quiz 1: 27 October 2024 (September 2024 term)

The IIT Madras BS Deep Learning for Computer Vision (Deep Learning for Computer Vision) Quiz 1 paper sat on 27 Oct 2024, in the September 2024 term: 30 questions for 48 marks in 120 minutes. Every question is below with its answer. Take it as a timed mock test to be marked, or read it through first.

Questions
30
Marks
48
Duration
120 min
MCQ
10
MSQ
5
Written
5
Numerical
10

Updated

Official paper: IIT M IMPROVEMENT AN EXAM QIM2 27 Oct 2024 · No negative marking.

Question 1

+2 marksOne correct option
  1. A

    54

  2. B

    10

  3. C

    0

  4. D

    18

Show answer

Correct answer

  • C

    0

Question 2

+2 marksOne correct option

Which of the following statements is false?

  1. A

    Linear contrast stretching is a point operation.

  2. B

    Moving average is an example of local operation.

  3. C

    Convolution in the spatial domain can be obtained through addition in the frequency domain.

  4. D

    All of these.

Show answer

Correct answer

  • C

    Convolution in the spatial domain can be obtained through addition in the frequency domain.

Question 3

+2 marksOne correct option

Which of the following statements is True

  1. A

    Gaussian filter is Separable filter because it is non linear.

  2. B

    Median filter is a non separable filter

  3. C

    Gaussian filter is a High Pass filter.

  4. D

    Mean filter is a non separable filter because it is non linear

Show answer

Correct answer

  • B

    Median filter is a non separable filter

Question 4

+2 marksOne correct option
  1. A

    0.18, 1.5, 1.5, 0.20,−1.5,−0.015

  2. B

    0.92, 2.5, 1, 2.5, 2.5, 1

  3. C

    0.18,−1.5, 0, 0.20, 0,−0.015

  4. D

    0.91, 1, 0, 0.2, 1, 1.7

Show answer

Correct answer

  • C

    0.18,−1.5, 0, 0.20, 0,−0.015

Question 5

+2 marksOne correct option

Identify the correct sequence of steps in a Canny edge detection pipeline. Steps are listed below: 1. Compute gradient magnitude and direction
2. Connect individual components
3. Smoothen the image
4. Threshold into strong, weak, or no edge
5. Gaussian Filter and Hysteresis
6. Non-maximum suppression
7. Apply derivative to get edges

  1. A

    6→ 1→ 4→ 5 → 2

  2. B

    3→ 1→ 6→ 4 → 2

  3. C

    3→ 5→ 1→ 4 → 2

  4. D

    6→ 8→ 5→ 7 → 2

Show answer

Correct answer

  • B

    3→ 1→ 6→ 4 → 2

Question 6

+2 marksOne correct option

Identify the correct sequence of steps in Scale Invariant Feature Transform (SIFT) method. Steps listed below:
1. Keypoint Descriptor
2. Keypoint Localization
3. Scale-space Extrema Detection
4. Orientation Estimation

  1. A

    4→ 2→ 1→ 3

  2. B

    3→ 2→ 4→ 1

  3. C

    3→ 1→ 2→ 4

  4. D

    None of these.

Show answer

Correct answer

  • B

    3→ 2→ 4→ 1

Question 7

+2 marksOne correct option
  1. A

    1→ iii, 2→ i, 3 → ii

  2. B

    1→ iii, 2→ ii, 3 → i

  3. C

    1→ ii, 2→ iii, 3 → i

  4. D

    None of these.

Show answer

Correct answer

  • A

    1→ iii, 2→ i, 3 → ii

Question 8

+2 marksOne correct option

Suppose we have a codebook of 2048 SIFT visual words. We extract 1000 SIFT descriptors (SIFT is a 128-dimensional feature) from a new image. What is the dimensionality of the BoW (Bag-of-Words) descriptor?

  1. A

    1000

  2. B

    128

  3. C

    128 × 2048

  4. D

    2048

Show answer

Correct answer

  • D

    2048

Question 9

+2 marksOne correct option

Match the derivative of activation functions f(x)f(x) with their counterparts on the right column accordingly.

1) Leaky ReLUi) f(x)(1−f(x))f(x)(1 - f(x))
2) Tanhii) 0 if x<0x < 0 and 1 if x>0x > 0
3) ReLUiii) 1−f(x)21 - f(x)^2
4) Sigmoidiv) 0.01 if x<0x < 0 and 1 if x>0x > 0
v) 0 if x⩾0x \geqslant 0 and 1 if x<0x < 0
vi) 0.01 if x⩾0x \geqslant 0 and 1 if x<0x < 0
  1. A

    1→ vi, 2→ iii, 3→ v, 4 → i

  2. B

    1→ i, 2 →iv, 3 → iii, 4→ ii

  3. C

    1→ i, 2 →v, 3 → iii, 4→ iv

  4. D

    1→ iv, 2→ iii, 3→ ii, 4 → i

Show answer

Correct answer

  • D

    1→ iv, 2→ iii, 3→ ii, 4 → i

Question 10

+2 marksOne correct option
  1. A

    5 × 5

  2. B

    7 × 7

  3. C

    9 × 9

  4. D

    3 × 3

Show answer

Correct answer

  • C

    9 × 9

Question 11

+2 marksOne or more correct options

Which of the following statements are false?

Select all that apply.

  1. A

    Momentum in optimization can cause oscillations around minima when encountering flat regions or saddle points due to the dominance of the momentum term over the small gradient.

  2. B

    Stochastic Gradient Descent (SGD) with its inherent noise can be beneficial in escaping local minima and saddle points, provided that there is enough gradient information in the neighborhood.

  3. C

    Adagrad is an optimization algorithm introduced to overcome the diminishing learning rate problem in techniques like RMSProp.

  4. D

    ADAM is introduced to solve problems in RMSProp by combining RMSProp and Adagrad techniques.

Show answer

Correct answers

  • C

    Adagrad is an optimization algorithm introduced to overcome the diminishing learning rate problem in techniques like RMSProp.

  • D

    ADAM is introduced to solve problems in RMSProp by combining RMSProp and Adagrad techniques.

Question 12

+2 marksOne or more correct options

Select all that apply.

  1. A
  2. B
  3. C
  4. D
Show answer

Correct answers

  • A
  • C

Question 13

+2 marksOne or more correct options

Select all that apply.

  1. A
  2. B
  3. C
  4. D
Show answer

Correct answers

  • A
  • D

Question 14

+2 marksOne or more correct options

Which of the following statements are true? (Select all that apply)

Select all that apply.

  1. A
  2. B
  3. C
  4. D
Show answer

Correct answers

  • A
  • D

Question 15

+2 marksOne or more correct options

Which of the following are true? (Select all that apply)

Select all that apply.

  1. A
  2. B
  3. C
  4. D
Show answer

Correct answers

  • A
  • B

Question 16

+0.5 marksWritten answer

The gradient of an image I, points in the direction of most rapid change in intensity, taking image derivatives accentuates (a) ____________ frequencies and hence amplifies noise, since the proportion of noise to signal is larger at (b) __________ frequencies. The solution to this is (c) _________ the image prior to computing gradients.
Based on the above data, answer the given subquestions.

Enter the correct answer for (a).
NOTE: Enter the exact answer without any space in the beginning or at the end.

Show answer

Correct answer: high

Question 17

+0.5 marksWritten answer

The gradient of an image I, points in the direction of most rapid change in intensity, taking image derivatives accentuates (a) ____________ frequencies and hence amplifies noise, since the proportion of noise to signal is larger at (b) __________ frequencies. The solution to this is (c) _________ the image prior to computing gradients.
Based on the above data, answer the given subquestions.

Enter the correct answer for (b).
NOTE: Enter the exact answer without any space in the beginning or at the end.

Show answer

Correct answer: high

Question 18

+1 markWritten answer

The gradient of an image I, points in the direction of most rapid change in intensity, taking image derivatives accentuates (a) ____________ frequencies and hence amplifies noise, since the proportion of noise to signal is larger at (b) __________ frequencies. The solution to this is (c) _________ the image prior to computing gradients.
Based on the above data, answer the given subquestions.

Enter the correct answer for (c).
NOTE: Enter the exact answer without any space in the beginning or at the end.

Show answer

Correct answer: smooth

Question 19

+1 markWritten answer

In Canny edge detection, large value of the Gaussian kernel spread, σ leads to (a) __________ edges, and small value of σ leads to (b) __________ edges.
Based on the above data, answer the given subquestions.

Enter the correct answer for (a).
NOTE: Enter the exact answer without any space in the beginning or at the end.

Show answer

Correct answer: thick or coarse or large scale

Question 20

+1 markWritten answer

In Canny edge detection, large value of the Gaussian kernel spread, σ leads to (a) __________ edges, and small value of σ leads to (b) __________ edges.
Based on the above data, answer the given subquestions.

Enter the correct answer for (b) .
NOTE: Enter the exact answer without any space in the beginning or at the end.

Show answer

Correct answer: fine

Question 21

+0.5 marksNumerical answer

Based on the above data, answer the given subquestions.

Enter the correct answer for a11

Show answer

Correct answer: 1

Question 22

+0.5 marksNumerical answer

Based on the above data, answer the given subquestions.

Enter the correct answer for a12

Show answer

Correct answer: 0.5

Question 23

+0.5 marksNumerical answer

Based on the above data, answer the given subquestions.

Enter the correct answer for a21

Show answer

Correct answer: 0

Question 24

+0.5 marksNumerical answer

Based on the above data, answer the given subquestions.

Enter the correct answer for a22

Show answer

Correct answer: 1

Question 25

+2 marksNumerical answer

Consider the following numpy array

arr=[012345]\text{arr} = \begin{bmatrix} 0 & 1 \\ 2 & 3 \\ 4 & 5 \end{bmatrix}

Now consider the following operations

flattened_arr=arr.flatten()\text{flattened\_arr} = \text{arr.flatten()}

flattened_arr[0]=10\text{flattened\_arr[0]} = 10

Write the value of arr[0]

Show answer

Correct answer: 0

Question 26

+2 marksNumerical answer

Consider the following numpy array

arr=[012345]\text{arr} = \begin{bmatrix} 0 & 1 \\ 2 & 3 \\ 4 & 5 \end{bmatrix}

Now consider the following operations

raveled_arr=arr.ravel()\text{raveled\_arr} = \text{arr.ravel()}

raveled_arr[0]=10\text{raveled\_arr[0]} = 10

Write the value of arr[0]

Show answer

Correct answer: 10

Question 27

+2 marksNumerical answer

Consider the grayscale image shown below:

[20302530404510403520152030255050403515301035252045]\begin{bmatrix} 20 & 30 & 25 & 30 & 40 \\ 45 & 10 & 40 & 35 & 20 \\ 15 & 20 & 30 & 25 & 50 \\ 50 & 40 & 35 & 15 & 30 \\ 10 & 35 & 25 & 20 & 45 \end{bmatrix}

If a median filter with a 3×33 \times 3 neighborhood is applied to this image with a stride of 1 and no padding, __________ will be the value at position (2,2)(2, 2) in the filtered image? (Assume that the top-left pixel coordinate of output image is addressed as (1,1)(1, 1))?

Show answer

Correct answer: 30

Question 28

+2 marksNumerical answer
Show answer

Correct answer: -0.315 (accepted within ±0.025)

Question 29

+2 marksNumerical answer
Show answer

Correct answer: 14

Question 30

+2 marksNumerical answer
Show answer

Correct answer: 1152