def rfft2d_freqs ( h , w ) : fy = np . fft . fftfreq ( h ) [ : , None ] # when we have an odd input dimension we need to keep one additional # frequency and later cut off 1 pixel if w % 2 == 1 : fx = np . fft . fftfreq ( w ) [ : w // 2 + 2 ] else : fx = np . fft . fftfreq ( w ) [ : w // 2 + 1 ] return np . sqrt ( fx * fx + fy * fy )
python 2d fft to power spectrum
Computes 2D spectrum frequencies .
def rfft2d_freqs(h, w):
    """Computes 2D spectrum frequencies."""

    fy = np.fft.fftfreq(h)[:, None]
    # when we have an odd input dimension we need to keep one additional
    # frequency and later cut off 1 pixel
    if w % 2 == 1:
        fx = np.fft.fftfreq(w)[: w // 2 + 2]
    else:
        fx = np.fft.fftfreq(w)[: w // 2 + 1]
    return np.sqrt(fx * fx + fy * fy)