The fractal systems are broadly found throughout the nature, generally in any scale. For each dimension (1D, 2D . . . ) in any structures and in any mathematical algorithms or in any object (sequence, line, square) its dimension can be calculated. These dimensions are specific parameters for description of the DNA sequence characters ACGT strings. Generally a first step consists in the converting of a one-dimensional sequence into the image. In the second step, the method for calculating the dimensions for all scales is selected. For the calculations of the above mentioned dimensions the Power Spectrum (PS) method has been proposed and examined. The Power Spectrum method provides universal calculation of dimension and it allows to obtain the resulting multifractal coefficient. The multifractal coefficient represents the means rate of approximation to ideal power spectrum. It has to be emphasized that the multifractal coefficient is independent of any scale to be chosen. Moreover, the multifractal coefficient serves as an advanced parameter for mathematical description of analyzed specific sequence of the deoxyribonucleic acid (DNA) or the whole genome. The conversion of the sequence into the image as the first step of the pre-processing can be used also for the alternative imaging and the description of sequence and it is possible to choose another method for the processing and analyzing a fractal image (for example Box Counting method). In the paper, the method for the processing of the DNA in the genome sequencing, the Power Spectrum method, will be introduced. The results of the Power Spectrum methods will be presented also.