Parametric dictionary

Parametric Dictionary Design Using Genetic Algorithm for Biomedical Image De-noisii Application... 

Keywords— parametric dictionary (PD), Equiangular tight frame (ETF), MGF, Genetic Algorithm, Biomedical CT Image. 

Unfortunately, EFT does not exist for all the combinations of d, N. In [15], it can be shown that, by alternating projection, we can find a matrix that is predicted to be close to ETF. The aim of parametric dictionary (PD) is to find a set of parameters that minimizes the distance between dictionary and the Gram matrix. 

In this paper, we studied the problems of parametric dictionary (PD) design for sparse representations. We can see that by minimizing the distance between C norm of column of designed dictionary and Gram matrix, the resultant dictionary will have the minimum mutual coherence compared to initial dictionary. By the mean of constant characteristic of gram matrix, we eliminate the iteration method that was used in previous methods, enabling better results. 

Standard dictionaries define semiempirical as involving assumptions, approximations, or generalizations designed to simplify calculation or to yield a result in accord with observation [1]. In this spirit, the semiempirical methods of quantum chemistry start out from the ab initio formalism and then introduce rather drastic assumptions to speed up the calculations, typically by neglecting many of the less important terms in the ab initio equations. In order to compensate for the errors caused by these approximations, empirical parameters are incorporated into the formalism and calibrated against reliable experimental or theoretical reference data. If the chosen semiempirical model retains the essential physics to describe the properties of interest, the parametrization may... 

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