Title
Toward Fast Transform Learning
Abstract
This paper introduces a new dictionary learning strategy based on atoms obtained by translating the composition of convolutions with -sparse kernels of known support. The dictionary update step associated with this strategy is a non-convex optimization problem. We propose a practical formulation of this problem and introduce a Gauss–Seidel type algorithm referred to as alternative least square algorithm for its resolution. The search space of the proposed algorithm is of dimension , which is typically smaller than the size of the target atom and much smaller than the size of the image. Moreover, the complexity of this algorithm is linear with respect to the image size, allowing larger atoms to be learned (as opposed to small patches). The conducted experiments show that we are able to accurately approximate atoms such as wavelets, curvelets, sinc functions or cosines for large values of K. The proposed experiments also indicate that the algorithm generally converges to a global minimum for large values of and .
Year
DOI
Venue
2015
10.1007/s11263-014-0771-z
International Journal of Computer Vision
Keywords
Field
DocType
Dictionary learning,Matrix factorization,Fast transform,Sparse representation,Global optimization,Gauss–Seidel
Sinc function,Global optimization,Convolution,Computer science,Sparse approximation,Deconvolution,Algorithm,Artificial intelligence,Optimization problem,Machine learning,Curvelet,Wavelet
Journal
Volume
Issue
ISSN
114
2
0920-5691
Citations 
PageRank 
References 
8
0.52
39
Authors
4
Name
Order
Citations
PageRank
Olivier Chabiron1292.49
F. Malgouyres211216.27
Jean-Yves Tourneret31154104.46
Nicolas Dobigeon42070108.02