fmix

**FMix** is a **data augmentation technique that generates mixing masks using Fourier-space filtering** — creating random, irregular binary masks with controllable frequency characteristics for more diverse and natural-looking image combinations. **How Does FMix Work?** - **Generate Noise**: Create random noise in Fourier space with controlled frequency spectrum. - **Filter**: Low-pass filter to control the smoothness of the resulting mask. - **Threshold**: Convert to binary mask via thresholding. - **Mix**: Apply the mask to combine two images, with labels mixed proportionally to mask area. - **Paper**: Harris et al. (2020). **Why It Matters** - **Diverse Masks**: Fourier-generated masks produce irregular, organic shapes unlike CutMix's rectangles. - **Controllable**: The frequency cutoff controls mask complexity (smooth blobs vs. fine-grained patterns). - **Better Than CutMix**: Irregular masks prevent the model from exploiting rectangular boundary patterns. **FMix** is **Fourier-designed masks for mixing** — using frequency-domain generation to create diverse, naturalistic mixing patterns.