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Poster
Using Block Coordinate Descent to Learn Sparse Coding Dictionaries with a Matrix Norm Update
- Citation Author(s):
- Submitted by:
- Bradley Whitaker
- Last updated:
- 23 April 2018 - 1:16pm
- Document Type:
- Poster
- Document Year:
- 2018
- Event:
- Presenters:
- Bradley Whitaker
- Paper Code:
- ICASSP18001
- Categories:
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Researchers have recently examined a modified approach to sparse coding that encourages dictionaries to learn anomalous features. This is done by incorporating the matrix 1-norm, or \ell_{1,\infty} mixed matrix norm, into the dictionary update portion of a sparse coding algorithm. However, solving a matrix norm minimization problem in each iteration of the algorithm
causes it to run more slowly. The purpose of this paper is to introduce block coordinate descent, a subgradient-like approach to minimizing the matrix norm, to the dictionary update. This approach removes the need to solve a convex optimization program in each iteration and dramatically reduces the time required to learn a dictionary. Importantly, the dictionary learned in this manner can still model anomalous features present in a dataset.