[ECE558] Project02 problem 2 (dft2, idf2)

import cv2
import argparse
import numpy as np
from matplotlib import pyplot as plt
import ast
import math

# function for dft2
def dft2(img):
    img = np.fft.fft(np.fft.fft(img,axis=0),axis=1)
    return img

# function for idft2
def idft2(fft):
    y, x = fft.shape
    return dft2(np.conjugate(fft))/(x*y)

# driver code
parser = argparse.ArgumentParser(description='2D convolution')
parser.add_argument('-i', action='store', dest='img_path',help='Enter image path (relative path)')
args = parser.parse_args()

img_path = args.img_path
img = cv2.imread(img_path)
img = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)

# normalize input image
y, x = img.shape
modified = np.zeros([y,x])
i = 0
maxF = img.max()
minF = img.min()
# apply transformation
while(i < y):
    j = 0
    while(j < x):
        modified[i][j] = ((img[i][j]-minF)/(maxF-minF));
        j += 1
    i += 1

img = dft2(modified)

# display phase and magnitude spectrum
fshift = np.fft.fftshift(img)
magnitude_spectrum = 20*np.log(np.abs(fshift))
phase =  np.angle(fshift)
imgishift = np.fft.ifftshift(fshift)
img = idft2(imgishift*255)
cv2.imshow('Result Spectrum',np.uint8(magnitude_spectrum))
cv2.imshow('Result Phase',np.uint8(phase))
cv2.waitKey(0)
cv2.destroyAllWindows()