Dictionary construction for sparse representation classification: A novel cluster-based approach

There has been a rapid development in sparse representation classification (SRC) since it came out. Most previous work on dictionary improvement was to enhance the classification performance by modifying the dictionary representation structure while this paper concentrates on the reduction of dictionary length with nearly no sacrifice in classification accuracy. A novel cluster-based dictionary construction approach for SRC is proposed in this paper. Both cluster technique and clustering evaluation index are introduced to help construct an optimal dictionary for better classification performance. Results of experiments have verified that the new dictionary does not lose discrimination ability while its running time is greatly reduced. Most importantly, its robustness is also preserved.