Wavelet packet decompositions for the analysis of 2-D fields with stationary fractional increments

Nonstationary two-dimensional random fields with wide-sense stationary fractional increments are introduced using a fractional order for their increments in two directions of space. Some of their properties are studied and their value in modeling nonstationary, possibly anisotropic, fields is shown via examples. A separable wavelet packet analysis proves to be a useful tool in analyzing this kind of texture as it leads to stationary wavelet packet coefficients.