LAPLACIAN DCT COEFFICIENT MODELS

Abstract

It is well known that the distribution of the discrete cosine transform (DCT) coefficients of most natural images follow a Laplace distribution. In this note, a collection of formulas is derived for the distribution of the actual DCT coefficient. The corresponding estimation procedures are derived by the method of moments and the method of maximum likelihood. Finally, the superior performance of the derived distributions over the standard Laplace model is illustrated. It is expected that this work could serve as a useful reference and lead to improved modeling with respect to image analysis and image coding.