Abstract
This paper presents a new probability density function (pdf), which approximates the distributions of discrete cosine transform (DCT) coefficients. Our discussion is based on the mathematical analysis using a doubly stochastic model reported by Lam and Goodman. In the contrast with their studies, we assume that the variance of the Gaussian distributions can be modeled by the Gamma distributions. The Kolmogorov-Smirnov (KS) test statistic of the proposed pdf for the high-energy AC coefficients is smaller than the Laplacian and Normal distribution, and is slightly larger than the general Gauss statistic.
