% Correlated Noise Detection
function[norm_fft_column_power, norm_fft_row_power]=image_power(column_mean, row_mean);
% This routine calculates the normalized spectral power of the image
% in the column and row directions
% Calculate power in column direction
fft_column=fft(column_mean-mean(column_mean));
N=length(fft_column);
fft_column_power=abs(fft_column(1:N/2)).^2;
norm_fft_column_power=fft_column_power./max(fft_column_power);
nyquist=1/2;
freq_column=(1:N/2)/(N/2)*nyquist;
% Calculate power in row direction
fft_row=fft(row_mean-mean(row_mean));
M=length(fft_row);
fft_row_power=abs(fft_row(1:M/2)).^2;
norm_fft_row_power=fft_row_power./max(fft_column_power);
freq_row=(1:M/2)/(M/2)*nyquist;
% Plot
figure (5)
plot(freq_column, norm_fft_column_power);
figure(6)
plot(freq_row, norm_fft_row_power);
