(eng): We propose methodology for the analysis of active regions on the Sun. It is based on high-order statistical moments of image histogram, particularly on its skewness. The methodology includes a new technique to select regions with possible formation of the flare. We track these areas in the time video sequences to search for triggers -- turning point(s), when the pre-flare phase changes to the full developed event. The frequency analysis in the flare formation areas is based on Fourier analysis, Morlet wavelets, and principal component analysis. Results have been evaluated to achieve the periods of oscillations stimulating the flare origin.