Stochastic Convolutional Sparse Coding

Xiong, Jinhui; Richtarik, Peter; Heidrich, Wolfgang

Stochastic Convolutional Sparse Coding

Files

047-054.pdf (3.04 MB)

paper_1010_supplement.pdf (2.18 MB)

Date

2019

Authors

Xiong, Jinhui
Richtarik, Peter
Heidrich, Wolfgang

Publisher

The Eurographics Association

Abstract

State-of-the-art methods for Convolutional Sparse Coding usually employ Fourier-domain solvers in order to speed up the convolution operators. However, this approach is not without shortcomings. For example, Fourier-domain representations implicitly assume circular boundary conditions and make it hard to fully exploit the sparsity of the problem as well as the small spatial support of the filters. In this work, we propose a novel stochastic spatial-domain solver, in which a randomized subsampling strategy is introduced during the learning sparse codes. Afterwards, we extend the proposed strategy in conjunction with online learning, scaling the CSC model up to very large sample sizes. In both cases, we show experimentally that the proposed subsampling strategy, with a reasonable selection of the subsampling rate, outperforms the state-of-the-art frequency-domain solvers in terms of execution time without losing the learning quality. Finally, we evaluate the effectiveness of the over-complete dictionary learned from large-scale datasets, which demonstrates an improved sparse representation of the natural images on account of more abundant learned image features.

        @inproceedings{10.2312:vmv.20191317
,
booktitle = {Vision, Modeling and Visualization
},
editor = {Schulz, Hans-Jörg and Teschner, Matthias and Wimmer, Michael
},
title = {{Stochastic Convolutional Sparse Coding
}},
author = {Xiong, Jinhui and 
Richtarik, Peter and 
Heidrich, Wolfgang 
},
year = {2019
},
publisher = {The Eurographics Association
},
ISBN = {978-3-03868-098-7
},
DOI = {10.2312/vmv.20191317
}
}