Processing of Images in Gas Discharge by Spatial Correlation Function and Fast Fourier Transform

Spatial correlation function and fast Fourier transform (FFT) are important methods in analysis of pattern. In this paper, images of square, hexagonal and random filaments state are obtained in dielectric barrier discharge system with decreasing applied voltage. The average distance between neighboring filaments is analyzed by spatial correlation. It increases with the decreasing of the applied voltage. For further investigation, these images are transformed to frequency domain and Fourier spectra are studied. It is found that the mode changes with voltage decreasing.