Turkish Journal of Electrical Engineering and Computer Sciences
Author ORCID Identifier
LEILA BOUSSAAD: 0000-0001-5175-5153
Abstract
Few-shot image classification benefits from data augmentation, yet most existing methods operate in pixel space with limited control over spectral semantics. We introduce a lightweight, frequency-guided augmentation strategy based on Variational Mode Decomposition (VMD). Our method constructs an offline, per-class ModeBank by decomposing downsampled luminance patches and retaining midband modes that encode class-specific texture patterns. During episodic training, VMD is never executed online: instead, for each support image, a same-class midband mode is selected and blended using PSNR-targeted scaling with a luminance energy cap, ensuring perceptual consistency. The augmentation is fast, reproducible, class-consistent, and integrates seamlessly into standard metric-based pipelines without modifying the backbone or training procedure. We evaluate our approach on multiple benchmarks, including CIFAR-FS, FC100, Tiny-ImageNet-200, and DTD under 5-way 1-shot and 5-shot settings, using Conv-4 and ResNet-12 backbones. Our results show consistent and statistically significant gains over strong ProtoNet baselines, with effect sizes ranging from small to large and most improvements observed in the challenging 1-shot regime. Ablation studies confirm the importance of targeted frequency selection, query-side consistency, energy/PSNR control, and adaptive mixing schedules. Our method demonstrates that structured, class-aligned frequency perturbations offer a principled and practical complement to spatial augmentations in few-shot learning.
DOI
10.55730/1300-0632.4196
Keywords
Few-shot learning, data augmentation, variational mode decomposition, frequency-domain augmentation, modebank
First Page
661
Last Page
681
Publisher
The Scientific and Technological Research Council of Türkiye (TÜBİTAK)
Creative Commons License

This work is licensed under a Creative Commons Attribution 4.0 International License.
Recommended Citation
BOUSSAAD, L (2026). Class-aligned frequency augmentation using variational mode decomposition forfew-shot image classification. Turkish Journal of Electrical Engineering and Computer Sciences 34 (4): 661-681. https://doi.org/10.55730/1300-0632.4196
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