电镜作业2

#Author：zhanghaonan
import cv2 as cv
import numpy as np
from matplotlib import pyplot as plt
import matplotlib.image as mpimg

def GaussianLowFilter(image,d):
    f = np.fft.fft2(image)
    fshift = np.fft.fftshift(f)
    s1 = np.log( np.abs( fshift ) )
    def make_transform_matrix(d):
        transfor_matrix = np.zeros(image.shape)
        center_point = tuple(map(lambda x:(x-1)/2,s1.shape))
        for i in range(transfor_matrix.shape[0]):
            for j in range(transfor_matrix.shape[1]):
                def cal_distance(pa,pb):
                    from math import sqrt
                    dis = sqrt((pa[0]-pb[0])**2+(pa[1]-pb[1])**2)
                    return dis
                dis = cal_distance(center_point,(i,j))
                transfor_matrix[i,j] = np.exp(-(dis**2)/(2*(d**2)))
        return transfor_matrix
    d_matrix = make_transform_matrix(d)
    new_img = np.abs(np.fft.ifft2(np.fft.ifftshift(fshift*d_matrix)))
    return new_img
img= cv.imread('zhn.jpg',0)#把你文件名输入进来，尾缀必须有.jpg或.png
img_d1=GaussianLowFilter(img,1.667)
plt.subplot(111)
plt.axis("off")
plt.imshow(img_d1,cmap="gray")
plt.title('Gaussianlow')
plt.show()