The Hybrid Spectral - Gradient Saliency Pruning: A combination of multiple filter scoring criteria
Keywords:
CNN compression, structured pruning, frequency domain, model optimizationAbstract
Deep convolutional neural networks (CNNs) have achieved remarkable performance in visual recognition but remain computationally expensive for deployment on embedded or edge devices. This paper introduces Hybrid Spectral–Gradient Saliency Pruning (HSGSP), a structured pruning framework that unifies spectral analysis and data-driven gradient saliency to achieve efficient CNN compression. The proposed method incorporates a lightweight Frequency Relevance Network (FRN) that learns to estimate the spectral importance of convolutional filters through frequency-band energy ratios, enabling fast, task-driven scoring. A hybrid saliency metric fuses the FRN’s spectral relevance with gradient-based Taylor sensitivity, ensuring filters are preserved only when important both spectrally and task-wise. An adaptive iterative schedule dynamically adjusts pruning intensity based on validation feedback, preventing over-pruning and maintaining stability. Experiments on CIFAR-10 and CIFAR-100 using VGG-16BN demonstrate up to 90% parameter reduction with negligible accuracy loss, outperforming recent structured pruning methods. Furthermore, on a Raspberry Pi 5, our pruned model delivers a 3.4x inference speedup while slightly improving accuracy, and when permitting only a 1% accuracy trade-off, the speedup increases dramatically to 7.5x. The results confirm that combining spectral cues with gradient saliency offers a robust and interpretable path toward efficient CNN deployment. The official implementation code of our method is available at https://github.com/locth/HSGSP.git.
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