uiz Space

May 2026 term · Deep Learning for Computer Vision · BSDA5006

Deep Learning for Computer Vision End Term: 13 September 2026 (May 2026 term)

The IIT Madras BS Deep Learning for Computer Vision (Deep Learning for Computer Vision) End Term paper sat on 13 Sept 2026, in the May 2026 term: 37 questions for 100 marks in 180 minutes. Every question is below with its answer. Take it as a timed mock test to be marked, or read it through first.

Questions
37
Marks
100
Duration
180 min
MCQ
20
MSQ
8
Numerical
9

Updated

Official paper: Deep Learning For Computer Vision 13 Sep 26 · No negative marking.

Question 1

+2 marksOne correct option

An RGB image of size 128×96 is stored with 32-bit floating-point values for every channel. Ignoring metadata, how many bytes are required?

  1. A

    36,864

  2. B

    73,728

  3. C

    147,456

  4. D

    294,912

Show answer

Correct answer

  • C

    147,456

Question 2

+2 marksOne correct option

Let a 1-D filter be h=[2,-1,3]. A library routine performs cross-correlation. Which filter should be supplied to the routine to reproduce mathematical convolution with h, ignoring boundary effects?

  1. A

    [2,-1,3]

  2. B

    [-2,1,-3]

  3. C

    [3,-1,2]

  4. D

    [3,1,2]

Show answer

Correct answer

  • C

    [3,-1,2]

Question 3

+2 marksOne correct option

At a point on an ideal straight intensity edge, the local image-gradient vector is most naturally interpreted as pointing:

  1. A

    Along the tangent direction of the edge

  2. B

    Approximately normal to the edge

  3. C

    Along the direction of maximum smoothing

  4. D

    Along the local isophote

Show answer

Correct answer

  • B

    Approximately normal to the edge

Question 4

+2 marksOne correct option

An image is smoothed successively with Gaussian kernels of standard deviations 2 and 3. Ignoring discretization, the equivalent single Gaussian has standard deviation:

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

Correct answer

  • C

Question 5

+2 marksOne correct option

Which design choice is most directly responsible for the rotation robustness of a SIFT descriptor?

  1. A

    Detecting candidate keypoints across multiple image scales

  2. B

    Expressing local gradient orientations relative to an assigned keypoint orientation

  3. C

    Normalizing the descriptor vector after histogram construction

  4. D

    Building an image pyramid without assigning an orientation

Show answer

Correct answer

  • B

    Expressing local gradient orientations relative to an assigned keypoint orientation

Question 6

+2 marksOne correct option

A hidden activation h is used by two downstream branches, and both branches affect the same scalar loss L. During backpropagation, the gradient with respect to h is obtained by:

  1. A

    Taking the larger of the two branch gradients

  2. B

    Summing the gradient contributions from the two branches

  3. C

    Multiplying the two branch gradients

  4. D

    Averaging the two branch gradients regardless of the graph

Show answer

Correct answer

  • B

    Summing the gradient contributions from the two branches

Question 7

+2 marksOne correct option

Suppose successive gradients keep pointing in a similar direction over several updates. Compared with plain gradient descent using the same nominal learning rate, momentum tends to:

  1. A

    Cancel updates in that direction

  2. B

    Build velocity in that direction while smoothing short-term gradient fluctuations

  3. C

    Make the gradient exactly unbiased

  4. D

    Force every parameter to use the same accumulated gradient

Show answer

Correct answer

  • B

    Build velocity in that direction while smoothing short-term gradient fluctuations

Question 8

+2 marksOne correct option

Training loss continues to decrease, but validation loss has begun to increase consistently. Which interpretation is most appropriate?

  1. A

    The model is necessarily underfitting

  2. B

    Generalization is worsening even though optimization on the training set is improving

  3. C

    The training objective is necessarily non-differentiable

  4. D

    The model has reached the global optimum on unseen data

Show answer

Correct answer

  • B

    Generalization is worsening even though optimization on the training set is improving

Question 9

+2 marksOne correct option

A 3×3 convolution maps 16 input channels to 32 output channels. If the input spatial size changes from 64×64 to 128×128 while the layer configuration is unchanged, the number of trainable convolution weights:

  1. A

    Doubles

  2. B

    Quadruples

  3. C

    Remains unchanged

  4. D

    Is halved

Show answer

Correct answer

  • C

    Remains unchanged

Question 10

+2 marksOne correct option

A convolution kernel is reused at many spatial locations. The gradient of the loss with respect to one kernel coefficient therefore contains:

  1. A

    A contribution from only the central output location

  2. B

    Contributions accumulated from all output locations where that coefficient was used

  3. C

    Only the gradient of the bias corresponding to that output channel

  4. D

    A contribution from exactly one spatial location chosen during the forward pass

Show answer

Correct answer

  • B

    Contributions accumulated from all output locations where that coefficient was used

Question 11

+2 marksOne correct option
  1. A

    It forces F(x) to be constant

  2. B

    The block can approach an identity mapping when the residual F(x) approaches zero

  3. C

    It prevents gradients from entering the residual branch

  4. D

    It makes every convolution invertible

Show answer

Correct answer

  • B

    The block can approach an identity mapping when the residual F(x) approaches zero

Question 12

+2 marksOne correct option

A depthwise-separable convolution first applies a spatial filter independently to each input channel and then uses a 1×1 convolution across channels. Its main computational advantage over a dense spatial convolution is that it:

  1. A

    Eliminates channel mixing from the layer

  2. B

    Factorizes spatial filtering and channel mixing into cheaper operations

  3. C

    Uses a larger spatial kernel with the same parameter count

  4. D

    Forces the number of output channels to equal the number of input channels

Show answer

Correct answer

  • B

    Factorizes spatial filtering and channel mixing into cheaper operations

Question 13

+2 marksOne correct option

When adapting a pretrained CNN to a related task with a relatively small labeled dataset, which training choice is generally the more conservative starting point?

  1. A

    Reinitialize the entire network and use a very large learning rate

  2. B

    Retain pretrained features and update them cautiously, often with a smaller learning rate than newly initialized layers

  3. C

    Freeze the newly added prediction head and update only the old classifier

  4. D

    Randomly permute pretrained channels before optimization

Show answer

Correct answer

  • B

    Retain pretrained features and update them cautiously, often with a smaller learning rate than newly initialized layers

Question 14

+2 marksOne correct option

Which processing pattern is characteristic of a two-stage object detector?

  1. A

    Dense prediction of final detections in one stage with no proposal-processing step

  2. B

    Generation of candidate regions followed by prediction on those candidate regions

  3. C

    Pixel-wise class prediction without object localization

  4. D

    Sequence-level prediction using recurrent hidden states

Show answer

Correct answer

  • B

    Generation of candidate regions followed by prediction on those candidate regions

Question 15

+2 marksOne correct option

For semantic image segmentation with C classes, the model output before the final class decision is naturally organized as:

  1. A

    One C-dimensional vector for the entire image only

  2. B

    A spatial grid with C class scores at each output location

  3. C

    One bounding box for each of the C classes

  4. D

    A sequence with one recurrent state per class and no spatial layout

Show answer

Correct answer

  • B

    A spatial grid with C class scores at each output location

Question 16

+2 marksOne correct option

Compared with a basic recurrent update, the gating mechanisms in LSTMs and GRUs are primarily intended to:

  1. A

    Remove nonlinearities from the recurrent computation

  2. B

    Regulate information retention and update across timesteps

  3. C

    Make the model invariant to permutation of the sequence

  4. D

    Replace recurrent state with a fixed convolution kernel

Show answer

Correct answer

  • B

    Regulate information retention and update across timesteps

Question 17

+2 marksOne correct option

In self-attention, changing the query vector for one token while keeping keys and values fixed directly changes:

  1. A

    The number of tokens in the sequence

  2. B

    The attention weights used to combine the value vectors for that token

  3. C

    The dimensionality of every value vector

  4. D

    The number of transformer layers

Show answer

Correct answer

  • B

    The attention weights used to combine the value vectors for that token

Question 18

+2 marksOne correct option

A standard way to convert an image for processing by a Vision Transformer is to:

  1. A

    Treat the complete image batch as a single token

  2. B

    Divide the image into patches and map the patches to token embeddings

  3. C

    Replace each patch with its ground-truth class before attention

  4. D

    Use only the global mean RGB value as the token sequence

Show answer

Correct answer

  • B

    Divide the image into patches and map the patches to token embeddings

Question 19

+2 marksOne correct option

Which statement correctly distinguishes the two model families?

  1. A

    A GAN necessarily contains an explicit encoder that outputs a Gaussian posterior

  2. B

    A VAE uses a latent-variable objective with a regularized approximate posterior, whereas a GAN uses an adversarial training objective

  3. C

    A VAE is trained only through a discriminator

  4. D

    GANs and VAEs have the same training objective but different optimizers

Show answer

Correct answer

  • B

    A VAE uses a latent-variable objective with a regularized approximate posterior, whereas a GAN uses an adversarial training objective

Question 20

+2 marksOne correct option

Classifier-free guidance during sampling is based on combining:

  1. A

    Predictions from two external classifiers trained on different label sets

  2. B

    Conditional and unconditional denoising predictions from the diffusion model

  3. C

    The forward-noise sample and a segmentation mask with equal weights

  4. D

    Two independently sampled latent codes without conditioning information

Show answer

Correct answer

  • B

    Conditional and unconditional denoising predictions from the diffusion model

Question 21

+3 marksOne or more correct options

Select all correct statements

Select all that apply.

  1. A

    A normalized averaging filter preserves a constant-valued region away from boundary effects.

  2. B

    Increasing Gaussian scale suppresses progressively finer image structure.

  3. C

    Image pyramids represent image information at multiple spatial scales.

  4. D

    Cross-correlation always flips the filter before applying it.

Show answer

Correct answers

  • A

    A normalized averaging filter preserves a constant-valued region away from boundary effects.

  • B

    Increasing Gaussian scale suppresses progressively finer image structure.

  • C

    Image pyramids represent image information at multiple spatial scales.

Question 22

+3 marksOne or more correct options

Select all correct statements .

Select all that apply.

  1. A

    Backpropagation applies the chain rule efficiently through a computation graph.

  2. B

    Regularization can change the learned solution even when the network architecture is unchanged.

  3. C

    Gradient-descent variants can modify how current and past gradient information is used to update parameters.

  4. D

    Improving training means validation performance must increase after every individual parameter update.

Show answer

Correct answers

  • A

    Backpropagation applies the chain rule efficiently through a computation graph.

  • B

    Regularization can change the learned solution even when the network architecture is unchanged.

  • C

    Gradient-descent variants can modify how current and past gradient information is used to update parameters.

Question 23

+3 marksOne or more correct options

Select all correct statements.

Select all that apply.

  1. A

    Weight sharing allows the same convolution kernel parameters to be used at multiple spatial locations.

  2. B

    Inception-style designs can use multiple processing branches.

  3. C

    Residual connections create shortcut paths across learned transformations.

  4. D

    Finetuning requires discarding all pretrained weights before optimization starts.

Show answer

Correct answers

  • A

    Weight sharing allows the same convolution kernel parameters to be used at multiple spatial locations.

  • B

    Inception-style designs can use multiple processing branches.

  • C

    Residual connections create shortcut paths across learned transformations.

Question 24

+3 marksOne or more correct options

Select all correct statements.

Select all that apply.

  1. A

    Two-stage detectors separate candidate-region generation from later prediction on candidates.

  2. B

    Single-stage detectors can produce final detection predictions without a separate proposal-processing stage.

  3. C

    Segmentation is a dense prediction task with spatially resolved outputs.

  4. D

    Object detection and segmentation necessarily produce identical output representations.

Show answer

Correct answers

  • A

    Two-stage detectors separate candidate-region generation from later prediction on candidates.

  • B

    Single-stage detectors can produce final detection predictions without a separate proposal-processing stage.

  • C

    Segmentation is a dense prediction task with spatially resolved outputs.

Question 25

+3 marksOne or more correct options

Select all correct statements .

Select all that apply.

  1. A

    Recurrent models can process ordered sequences of visual features.

  2. B

    Backpropagation through a recurrent model propagates gradient information across unrolled timesteps.

  3. C

    LSTMs and GRUs use gating mechanisms.

  4. D

    Randomly permuting all video frames leaves every temporal model output unchanged by definition.

Show answer

Correct answers

  • A

    Recurrent models can process ordered sequences of visual features.

  • B

    Backpropagation through a recurrent model propagates gradient information across unrolled timesteps.

  • C

    LSTMs and GRUs use gating mechanisms.

Question 26

+3 marksOne or more correct options

Select all correct statements.

Select all that apply.

  1. A

    Soft attention can form a weighted combination of visual features.

  2. B

    Self-attention allows token representations to depend directly on other tokens.

  3. C

    Vision Transformers adapt transformer-style token processing to visual inputs.

  4. D

    Transformer-based segmentation is restricted to producing one class label for an entire image.

Show answer

Correct answers

  • A

    Soft attention can form a weighted combination of visual features.

  • B

    Self-attention allows token representations to depend directly on other tokens.

  • C

    Vision Transformers adapt transformer-style token processing to visual inputs.

Question 27

+3 marksOne or more correct options

Select all correct statements.

Select all that apply.

  1. A

    GAN training involves adversarial objectives.

  2. B

    VAEs introduce latent variables and regularize an approximate posterior.

  3. C

    DDPMs use a noise-based forward process together with a learned reverse denoising process.

  4. D

    Classifier-free guidance requires a separate external classifier at sampling time.

Show answer

Correct answers

  • A

    GAN training involves adversarial objectives.

  • B

    VAEs introduce latent variables and regularize an approximate posterior.

  • C

    DDPMs use a noise-based forward process together with a learned reverse denoising process.

Question 28

+3 marksOne or more correct options

Select all correct statements .

Select all that apply.

  1. A

    SimCLR is a self-supervised contrastive representation-learning method.

  2. B

    MoCo is a contrastive representation-learning method.

  3. C

    CLIP learns relationships between visual and textual representations.

  4. D

    In SimCLR, a positive pair is formed by two unrelated images solely because they receive the same predicted class.

Show answer

Correct answers

  • A

    SimCLR is a self-supervised contrastive representation-learning method.

  • B

    MoCo is a contrastive representation-learning method.

  • C

    CLIP learns relationships between visual and textual representations.

Question 29

+4 marksNumerical answer

An input feature map has spatial size 63×63. A 5×5 convolution is applied with stride 2 and padding 1. Compute the output size along one spatial dimension.

Show answer

Correct answer: 31

Question 30

+4 marksNumerical answer

An image is smoothed successively by Gaussian kernels with σ1=1.2 and σ2=1.6. Ignoring discretization, compute the equivalent single Gaussian standard deviation.

Show answer

Correct answer: 2.0

Question 31

+4 marksNumerical answer
Show answer

Correct answer: 4

Question 32

+4 marksNumerical answer

A convolutional layer uses 3×3 kernels, 16 input channels and 32 output channels. The layer has one bias per output channel. Compute the total number of trainable parameters.

Show answer

Correct answer: 4640

Question 33

+4 marksNumerical answer

A depthwise-separable convolution receives 32 channels. It uses a 3×3 depthwise convolution followed by a 1×1 pointwise convolution producing 64 output channels. Ignore biases. Compute the total number of weights.

Show answer

Correct answer: 2336

Question 34

+4 marksNumerical answer
Show answer

Correct answer: 152

Question 35

+4 marksNumerical answer
Show answer

Correct answer: 0.731 (accepted within ±0.001)

Question 36

+4 marksNumerical answer
Show answer

Correct answer: 0.818 (accepted within ±0.001)

Question 37

+4 marksNumerical answer
Show answer

Correct answer: 1.364 (accepted within ±0.001)