Cross-Domain Cereal Crop Classification in Algeria using Fourier Domain Adaptation and Swin Transformers
# Cross-Domain Cereal Crop Classification in Algeria
## Using Fourier Domain Adaptation and Swin Transformers
> **Paper:** Cross-Domain Cereal Crop Classification in Algeria using Fourier Domain Adaptation and Swin Transformers
A data-efficient deep learning framework for crop classification in Algeria using Sentinel-2 satellite imagery. We leverage the label-rich **PASTIS dataset** (France) and transfer knowledge to North Africa using **Fourier Domain Adaptation (FDA)** combined with **Swin Transformers**.
## 📌 Key Results
| Method | F1-Score | Notes |
|--------|----------|-------|
| Target Only | 39.2% | Severe overfitting |
| Direct Transfer | 58.7% | Domain shift failure |
| Mixed Batch (No FDA) | 88.3% | Limited by spectral shift |
| MT-ADA (Iftene & Larabi, 2024) | 80.0% | Feature-level alignment |
| **Ours (FDA+Mix)** | **93.2% ± 1.9%** | **State-of-the-Art** |
**Potato Classification (Generalization Test):** 85.6% ± 2.4% F1-Score
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## 🔬 Methodology Overview
### The Problem
1. **Label Scarcity:** Large labeled datasets are scarce in Algeria compared to Europe
2. **Spectral Domain Shift:** Different atmospheric conditions, sun angles, and soil types
3. **Phenological/Temporal Shift:** Different growing seasons between Europe and North Africa
### Our Solution
Our framework combines three key innovations:
#### 1. Max-NDVI Compression
Instead of using full time-series data (susceptible to phenological shifts), we compute the **Maximum NDVI** across the temporal dimension:
$$\text{Max-NDVI}(x, y) = \max_{t \in T} \left( \frac{NIR_{t} - Red_{t}}{NIR_{t} + Red_{t}} \right)$$
This creates a time-invariant feature that captures peak vegetative vigor regardless of when it occurred.
#### 2. Fourier Domain Adaptation (FDA)
FDA transfers the "style" (spectral characteristics) of Algerian images to European images while preserving their "content" (field boundaries, structures):
```
Source Image (Europe) + Target Style (Algeria) → Adapted Image
``` …