Firstly, several simulations will be carried out to verify the convergence performance of the proposed CCDL. As the main contributions of the new method lie in the dictionary updating stage, we focus on the performance of designing the orthonormal matrices U and V, that is, solving (26).
Figures 1 and 2 show the efficiency of the proposed CCDL, where the authentic dictionary is generated with an ideal format as (47).
For convenience, the learning systems are denoted as [Dict.sub.new], [Dict.sub.ksvd], [Dict.sub.BP], and [Dict.sub.SDB] for the proposed CCDL and the methods in the references just mentioned, respectively.
For CCDL, the maximum iteration numbers for the loops indexed by k and j are fixed as 100 and 10, respectively.