Title
Learning computationally efficient dictionaries and their implementation as fast transforms.
Abstract
Dictionary learning is a branch of signal processing and machine learning that aims at finding a frame (called dictionary) in which some training data admits a sparse representation. The sparser the representation, the better the dictionary. The resulting dictionary is in general a dense matrix, and its manipulation can be computationally costly both at the learning stage and later in the usage of this dictionary, for tasks such as sparse coding. Dictionary learning is thus limited to relatively small-scale problems. In this paper, inspired by usual fast transforms, we consider a general dictionary structure that allows cheaper manipulation, and propose an algorithm to learn such dictionaries --and their fast implementation-- over training data. The approach is demonstrated experimentally with the factorization of the Hadamard matrix and with synthetic dictionary learning experiments.
Year
Venue
DocType
2014
CoRR
Journal
Volume
Citations 
PageRank 
abs/1406.5388
4
0.43
References 
Authors
7
2
Name
Order
Citations
PageRank
Luc Le Magoarou1145.02
Rémi Gribonval2120783.59