preprocess.py 文件源码

def blkwl(img):
    """Calculate wavelength  given an image block"""
    f=np.abs(fftshift(fft2(img)))
    origin=np.where(f==np.max(f));f[origin]=0;mmax=np.where(f==np.max(f))
    wl=2*img.shape[0]/(((origin[0]-mmax[0][0])*2)**2+((origin[1]-mmax[1][0])*2)**2)**0.5
    return wl