[FIXED] Fourier Transform 2D artifact - what am I doing wrong?

Issue

So currently I'm trying to wrap my head around the fourier transform (in 2D). I wanted to fourier transform an image and return back in only the magnitude spectrum just like this topic on this site:

https://dsp.stackexchange.com/questions/16995/image-reconstructionphase-vs-magnitude

However my image (using spyder ide) comes out like this with some weird artificant in the middle, using the same image from the link above.

original image:

Magnitude spectrum:

The code that I'm using is in python using numpy (np), OpenCV and Matplotlib:

import numpy as np
import cv2
from matplotlib import pyplot as plt
from os import listdir
from os.path import isfile, join


image1 = cv2.imread("Images/test2.png", 0)
fourier = np.fft.fft2(image1)
magnitude = abs(fourier)
inverse = np.fft.ifftshift(np.fft.ifft2(magnitude))
plt.subplot(), plt.imshow(np.uint8(inverse), cmap='gray')
plt.title(''), plt.xticks([]), plt.yticks([])
plt.show()

What am I doing wrong?

Update: added imports

Solution

You can try changing the np.uint8 to np.abs. Since you want clipping above 255 and not modulus you should do something like this:

inverse = np.fft.ifftshift(np.fft.ifft2(magnitude))
inv = np.abs(inverse)
inv[inv > 255] = 255
plt.subplot(), plt.imshow(inv, cmap='gray')

Answered By - Aguy