python-opencv实现低通滤波

python-opencv实现低通滤波

import os
import cv2
import numpy as np
import matplotlib.pyplot as plt
def read_img(img_7_path):
    img=cv2.imread(img_7_path,0)
    dft=cv2.dft(np.float32(img),flags=cv2.DFT_COMPLEX_OUTPUT)
    dftshift=np.fft.fftshift(dft)
    rows,cols=img.shape
    crow,ccol=int(rows/2),int(cols/2)
    mask=np.zeros((rows,cols,2),np.uint8)
    mask[crow-30:crow+30,ccol-30:ccol+30]=1
    fshit=dftshift*mask
    ishit=np.fft.ifftshift(fshit)
    iImg=cv2.idft(ishit)
    iImg=cv2.magnitude(iImg[:,:,0],iImg[:,:,1])
    plt.subplot(121), plt.imshow(img, cmap='gray')
    plt.title('orignal'), plt.axis('off')
    plt.subplot(122),plt.imshow(iImg,cmap='gray')
    plt.title('inverse'),plt.axis('off')
    plt.show()
if __name__ == '__main__':
    work_path = os.getcwd()
    data_path = os.path.join(work_path, 'data')
    img_7_path = os.path.join(data_path, '7.jpg')
    read_img(img_7_path)