Transfer learning for vision
Reusing a model trained on a large vision dataset as a starting point for your smaller task—**transfer learning** / fine-tuning.
What it is
Reusing a model trained on a large vision dataset as a starting point for your smaller task—transfer learning / fine-tuning.
Why it matters
Most practical vision wins don’t train from scratch. Transfer is the default builder move.
How it works (plain)
Take a pretrained backbone → replace/train the head → optionally fine-tune deeper layers with a low LR. Match preprocessing to the pretrained recipe.
Everyday example
A chef who already knows knife skills learning a new cuisine faster than a beginner.
Try it
Fine-tune a small classifier on a tiny personal image set; compare to training from scratch if compute allows.
Myths
- ⚠️ Myth: Freezing everything always wins.
- ✓ Reality: Domain shift often needs careful unfreezing.
- ⚠️ Myth: Any pretrained model transfers everywhere.
- ✓ Reality: Medical/satellite domains may need domain-specific pretraining.
Sources
- Course 05 CNNs; Course 12 vision
- fast.ai: https://www.fast.ai/ ↗
