Four methods to estimate the fractal dimension from self-affine signals (medical application)

Four methods for estimating the fractal dimension, namely, relative dispersion, correlation, rescaled range, and Fourier (spectral) analysis, are described. Modifications of these methods for use on self-similar or self-affine signals are presented. It is found that correlation analysis and rescaled range analysis yield seriously biased results under many circumstances. Relative dispersion analysis is well suited for long signals. Spectral analysis gives the least biased results, and also has lowest variance in the estimates of the fractal dimension.<>