% make FFT log magnitude image w/ full scale contrast

function [y] = LogMagSpectrum(x)

z = log(1 + abs(fftshift(fft2(x))));

zmin = min(min(z));
zmax = max(max(z));

K = 255.0 / (zmax - zmin);

y = K * (z - zmin);

return;
