Fourier Transform of Image
Fourier Transform is used to analyze the frequency characteristics of various filters.
Here we will use numpy function np.fft.fft2()
import numpy as np import cv2 from matplotlib import pyplot as plt img = cv2.imread('C:/Users/user/Desktop/python/image.jpg') f = np.fft.fft2(img) fshift = np.fft.fftshift(f) magnitude_spectrum = 20*np.log(np.abs(fshift)) plt.subplot(121),plt.imshow(img, cmap = 'gray') plt.title('Input Image'), plt.xticks([]), plt.yticks([]) plt.subplot(122),plt.imshow(magnitude_spectrum, cmap = 'gray') plt.title('Magnitude Spectrum'), plt.xticks([]), plt.yticks([]) plt.show()
For more see OpenCV doc
http://docs.opencv.org/trunk/de/dbc/tutorial_py_fourier_transform.html