Convolutional Neural Networks

Tuesday, 19 Aug 2025 Tutorial

Overview

Learn the fundamentals of Convolutional Neural Networks (CNNs) with step-by-step tutorials, video guides, and practical applications.

Convolutional Neural Networks

Definition

Convolutional Neural Networks (CNNs) are a class of deep learning models specifically designed for processing structured grid data, such as images. They use convolutional layers to automatically learn spatial hierarchies of features.

Types / Variants

  • Sequential CNNs: Layers are stacked sequentially for simple architectures.
  • Functional API CNNs: Allows building complex architectures with multiple inputs/outputs.
  • Subclassed CNNs: Custom models by subclassing the Model class in frameworks like TensorFlow.

Key Concepts

  • Convolutional Layers: Extract features using filters (kernels).
  • Pooling Layers: Reduce spatial dimensions and computation while retaining important features.
  • Fully Connected Layers: Combine extracted features to perform classification or regression.
  • Activation Functions: Non-linear transformations like ReLU applied to feature maps.
  • Overfitting Prevention: Use dropout, data augmentation, and regularization.

Tutorials

Videos

• Live coding of a CNN in TensorFlow 2: building, training, and evaluating on MNIST.

• Step-by-step code for a CNN using Keras on CIFAR-10: model layers, training, and evaluation.

• Beginner-friendly coding session: define convolutional layers, pooling, and fully connected networks in Python.

Applications

  • Image classification (e.g., MNIST digits, CIFAR-10 images).
  • Object detection and localization in images.
  • Medical imaging analysis (e.g., tumor detection in MRI scans).
  • Self-driving cars: detecting pedestrians, traffic signs, and obstacles.

Resources

Tips & Best Practices

  • Always normalize image data before feeding it into a CNN.
  • Use data augmentation to improve generalization and prevent overfitting.
  • Start with small models and gradually increase complexity.
  • Visualize intermediate feature maps to understand what the network is learning.