On the distribution of the DCT coefficients

The paper presents a statistical study in order to improve the image compression rate in discrete cosine transform (DCT) based methods and especially for compression methods which are defined in JPEG norm. It is realised extensively, using a battery of parametric and non-parametric fit-tests and laws such as those of Cauchy, Laplace, Gauss, and a mixture distribution of Laplace and Gaussian. Considering the absence of results for these laws in the literature, the authors constructed adapted statistical tools for DCT coefficients analysis. Then, they show that these coefficients can be modelized by a Gaussian finite mixture distribution. They also comment on the obtained results for medical images applications and explain how the compression rate can be improve with them