Skip to main content

Command Palette

Search for a command to run...

πŸ–ΌοΈ CNN Explained Like You're 5

Published
β€’2 min read
S

Building AI systems and writing about how they actually work. Master of AI @ University of Technology Sydney. Previously B.Tech CS with focus on IoT. I believe the best way to learn is to explain. That's why I'm documenting tech concepts with simple analogies (@sreekarreddy.com). AWS Certified β€’ Azure AI Certified β€’ Neo4j Professional β€’ Google Data Analytics When not coding: exploring Sydney, working on side projects, and teaching tech to anyone who'll listen.

Neural networks that see patterns in images

Day 74 of 149

πŸ‘‰ Full deep-dive with code examples


The Magnifying Glass Analogy

Look at a photo through a small magnifying glass.

Step 1: Slide it across, examining small patches Step 2: In each patch, notice features: edges, colors Step 3: Combine all patches to understand the full picture

That's exactly what CNNs do!


How CNNs Work

Photo of Cat
     ↓
Layer 1: "I see edges and lines"
     ↓
Layer 2: "Those edges form shapes - circles, triangles"
     ↓
Layer 3: "Those shapes look like ears, eyes, whiskers"
     ↓
Output: "This is a cat! 🐱"

Each layer builds on the previous one, detecting increasingly complex features.


The "Convolutional" Part

A small filter (like 3x3 pixels) slides across the image:

β”Œβ”€β”€β”€β”¬β”€β”€β”€β”¬β”€β”€β”€β”
β”‚ 1 β”‚ 0 β”‚ 1 β”‚  ← This filter detects vertical edges
β”œβ”€β”€β”€β”Όβ”€β”€β”€β”Όβ”€β”€β”€β”€
β”‚ 1 β”‚ 0 β”‚ 1 β”‚
β”œβ”€β”€β”€β”Όβ”€β”€β”€β”Όβ”€β”€β”€β”€
β”‚ 1 β”‚ 0 β”‚ 1 β”‚
β””β”€β”€β”€β”΄β”€β”€β”€β”΄β”€β”€β”€β”˜

Different filters detect different features!


Real-World Uses

  • Facial recognition: Unlocking your phone
  • Medical imaging: Detecting tumors in X-rays
  • Self-driving cars: Recognizing pedestrians and signs
  • Quality control: Finding defects in manufacturing

In One Sentence

CNNs are neural networks specialized for images that detect features layer by layer, from simple edges to complex objects.


πŸ”— Enjoying these? Follow for daily ELI5 explanations!

Making complex tech concepts simple, one day at a time.

More from this blog

esreekarreddy

132 posts