eprintid: 1530 rev_number: 6 eprint_status: archive userid: 45 dir: disk0/00/00/15/30 datestamp: 2013-03-07 14:02:16 lastmod: 2013-03-12 14:58:11 status_changed: 2013-03-07 14:02:16 type: article metadata_visibility: show creators_name: Rusu, Cristian creators_name: Dumitrescu, Bogdan creators_id: cristian.rusu@imtlucca.it creators_id: title: Stagewise K-SVD to Design Efficient Dictionaries for Sparse Representations ispublished: pub subjects: QA75 divisions: CSA full_text_status: none keywords: classification, coding, dataset, dictionaries, error constraint, pattern recognition, sparse representations, stagewise K-SVD abstract: The problem of training a dictionary for sparse representations from a given dataset is receiving a lot of attention mainly due to its applications in the fields of coding, classification and pattern recognition. One of the open questions is how to choose the number of atoms in the dictionary: if the dictionary is too small then the representation errors are big and if the dictionary is too big then using it becomes computationally expensive. In this letter, we solve the problem of computing efficient dictionaries of reduced size by a new design method, called Stagewise K-SVD, which is an adaptation of the popular K-SVD algorithm. Since K-SVD performs very well in practice, we use K-SVD steps to gradually build dictionaries that fulfill an imposed error constraint. The conceptual simplicity of the method makes it easy to apply, while the numerical experiments highlight its efficiency for different overcomplete dictionaries. date: 2012 date_type: published publication: IEEE Signal Processing Letters volume: 19 number: 10 publisher: IEEE pagerange: 631-634 id_number: 10.1109/LSP.2012.2209871 refereed: TRUE issn: 1070-9908 official_url: http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=6247465&isnumber=6249741 citation: Rusu, Cristian and Dumitrescu, Bogdan Stagewise K-SVD to Design Efficient Dictionaries for Sparse Representations. IEEE Signal Processing Letters, 19 (10). pp. 631-634. ISSN 1070-9908 (2012)