Asymptotic Spectral Representation of Linear Convolutional Layers



Yi, Xinping ORCID: 0000-0001-5163-2364
(2022) Asymptotic Spectral Representation of Linear Convolutional Layers. IEEE Transactions on Signal Processing, 70. pp. 566-581.

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Abstract

By stacking a number of convolutional layers, convolutional neural networks (CNNs) have made remarkable performance boosts in many artificial intelligence applications. While the convolution operation is well-understood, it is still a mystery why repeated convolutions yield so good expressive power and generalization performance. Noting that the linear convolution operation can be represented as a matrix-vector product with the matrix being of a Toeplitz structure, we propose to inspect the individual convolutional layer through its asymptotic spectral representation - the spectral density matrix - by leveraging Toeplitz matrix theory. Thanks to such spectral representation, we are able to develop a simple singular value approximation method with improved accuracy, and spectral norm upper bounds with reduced computational complexity, compared with the state-of-the-art methods. Both the improved approximation and upper bounds can be employed as regularization techniques to further enhance the generalization performance of CNNs. By extensive experiments on well-deployed CNN models (e.g., ResNets), we also demonstrate that the approximation approach achieves higher accuracy and the upper bounds are effective spectral regularizers for generalization.

Item Type: Article
Divisions: Faculty of Science and Engineering > School of Electrical Engineering, Electronics and Computer Science
Depositing User: Symplectic Admin
Date Deposited: 12 Jan 2022 15:58
Last Modified: 17 Mar 2024 13:17
DOI: 10.1109/tsp.2022.3140718
Related URLs:
URI: https://livrepository.liverpool.ac.uk/id/eprint/3146128