Deep Learning & Computer Vision Notes
Subject Overview
Year 2 (Deep Learning & Language) moves into neural networks — how modern AI actually works under the hood, from a single neuron to transformers. This semester's goal is to understand neural networks deeply enough to design, train and debug them for vision tasks: fundamentals and PyTorch, training technique, convolutional networks, transfer learning, and advanced computer vision.
Subject at a glance
8
Units
33
Topics
15
Hours
8
Infographics
Unit-wise Syllabus
8 units — click WhatsApp below to get the full notes for each
Unit 1: Neural Network Fundamentals (3 hours)
- Perceptrons
- activation functions
- forward and backward propagation
- building a neural network from scratch in NumPy
- 1Forward pass
Inputs × weights + bias, then activation
- 2Compute loss
Compare prediction with truth
- 3Backward pass
Gradients via the chain rule
- 4Update weights
Optimizer step
- 5Repeat for many epochs
Study guide
This module builds the foundation of deep learning: perceptrons, activation functions, forward and backward propagation and building a neural network from scratch in NumPy. Building it yourself once makes every framework make sense.
Unit 2: PyTorch Essentials (3 hours)
- Tensors
- autograd
- nn.Module
- datasets and dataloaders
- training loops
- why PyTorch dominates research
- 1. Load a batch: DataLoader
- 2. Forward: outputs = model(x)
- 3. Loss: loss = criterion(...)
- 4. Backward: loss.backward()
- 5. Step: optimizer.step()
- 6. Reset: optimizer.zero_grad()
Study guide
You learn PyTorch: tensors, autograd, nn.Module, datasets and dataloaders, training loops and why PyTorch dominates research. Write a full training loop by hand before using any helper library.
Unit 3: Training Deep Networks (3 hours)
- Optimizers (SGD, Adam)
- learning rate schedules
- regularization
- batch norm
- dropout
- debugging training
Overfitting
Train good, validation poor
Dropout, weight decay, augmentation, more data
Underfitting
Both poor
Bigger model, train longer, better features
Unstable loss
Loss jumps or becomes NaN
Lower learning rate, batch norm, gradient clipping
Slow progress
Loss falls very slowly
Adam, learning rate schedule
Study guide
Training deep networks is part craft: optimisers (SGD, Adam), learning rate schedules, regularisation, batch norm, dropout and debugging training. Learn to read loss curves to diagnose overfitting and underfitting.
Unit 4: Convolutional Neural Networks (4 hours)
- Convolutions
- pooling
- classic architectures (LeNet, ResNet, EfficientNet)
- image classification end-to-end
- 1
Input image
e.g. 224 × 224 × 3
- 2
Convolution
Filters detect edges and textures
- 3
Activation
ReLU
- 4
Pooling
Downsample, keep strongest signals
- 5
Deeper conv blocks
Shapes, then objects
- 6
Fully connected + softmax
Class probabilities
Study guide
Convolutional neural networks power image understanding: convolutions, pooling, classic architectures (LeNet, ResNet, EfficientNet) and end-to-end image classification. Understand why convolutions suit images.
Unit 5: Transfer Learning & Fine-tuning (3 hours)
Using pretrained models from Hugging Face and torchvision, feature extraction versus fine-tuning
Pretrained layers
Frozen
Some or all unfrozen
Data needed
Little
More
Compute
Low
Higher
Best when
New task is similar to the original
New domain differs, e.g. medical images
Study guide
Transfer learning reuses what pretrained models have learned: using models from Hugging Face and torchvision, and feature extraction versus fine-tuning. Fine-tuning a pretrained model usually beats training from scratch on small data.
Unit 6: Advanced CV Tasks (4 hours)
- Object detection (YOLO)
- segmentation (U-Net, SAM)
- image generation basics and diffusion intuition
Classification
One label per image
ResNet, EfficientNet
Object detection
Boxes + labels
YOLO
Segmentation
A label for every pixel
U-Net, SAM
Generation
New images
Diffusion models
Study guide
Advanced computer vision covers object detection (YOLO), segmentation (U-Net, SAM), image generation basics and diffusion intuition. Run a detector on your own photos.
Unit 7: Tools introduced
- PyTorch
- Hugging Face transformers and datasets
- Google Colab Pro / Kaggle GPUs for training
- Roboflow for dataset preparation
- Cursor with Claude in agentic mode for refactoring training code
PyTorch
Build and train networks
Hugging Face
Pretrained models and datasets
Colab and Kaggle GPUs
Free or cheap compute
Roboflow
Label and prepare image data
AI coding agents
Refactor training code
Study guide
The tools are PyTorch, Hugging Face transformers and datasets, Colab Pro and Kaggle GPUs, Roboflow for dataset preparation and Cursor with Claude in agentic mode for refactoring training code. Learn to prepare and label data well, since data quality drives results.
Unit 8: Mini-projects
- Build a CNN from scratch to classify CIFAR-10
- fine-tune a ResNet for a custom domain (e.g. plant disease detection)
- deploy an object detector to a webcam feed using YOLOv8
- 1Collect and label leaf images
- 2Augment
Flips, crops, colour jitter
- 3Fine-tune a pretrained ResNet
- 4Evaluate
Confusion matrix per disease
- 5Deploy
Webcam or phone demo
Study guide
The mini-projects are a CNN from scratch for CIFAR-10, a fine-tuned ResNet for a custom domain such as plant disease detection and a YOLOv8 object detector on a webcam feed. A working webcam demo is a striking portfolio piece.
Why Deep Learning & Computer Vision Matters
Deep learning drives modern computer vision, speech and language systems. Skills in PyTorch, transfer learning and detection are in high demand in AI engineering, robotics, healthcare imaging and agriculture technology.
How to Prepare for Deep Learning & Computer Vision
- Build a network from scratch once, then move to PyTorch.
- Monitor training and validation loss to catch overfitting early.
- Fine-tune pretrained models on a dataset you collect yourself.
Deep Learning & Computer Vision: Frequently Asked Questions
What is transfer learning?
Transfer learning reuses a model trained on a large dataset as the starting point for a new task, which saves data and time.
Why is PyTorch popular?
PyTorch is flexible, easy to debug and widely used in research, which makes new methods available in it first.
