Clean fft.py

datasets/raise/fft/fft.py

@@ -0,0 +1,41 @@
+from scipy import fftpack
+import numpy as np
+import imageio
+from PIL import Image, ImageDraw
+import matplotlib.pyplot as plt
+
+image = imageio.imread('image.jpg', mode = 'L')
+#plt.imshow(image, cmap = 'grey')
+#plt.show()
+
+# convert image to numpy array
+imageNp = np.array(image)
+
+# fft of image
+fft1 = fftpack.fftshift(fftpack.fft2(imageNp))
+
+# create a low pass filter image
+x, y = imageNp.shape
+# size of circle
+CIRCLE_RADIUS = 50
+eX, eY = CIRCLE_RADIUS, CIRCLE_RADIUS
+# create a box
+middleX, middleY = x / 2, y / 2
+bbox = (middleX - eX, middleY - eY, middleX + eX, middleY + eY)
+
+lowPass = Image.new('L', imageNp.shape, color = 0)
+
+draw = ImageDraw.Draw(lowPass)
+draw.ellipse(bbox, fill = 1)
+
+lowPassNp = np.array(lowPass)
+
+# multiply both the images
+filtered = np.multiply(fft1, lowPassNp.T)
+
+# inverse fft
+ifft2 = np.real(fftpack.ifft2(fftpack.ifftshift(filtered)))
+ifft2 = np.maximum(0, np.minimum(ifft2, 255))
+
+# save the image
+imageio.imsave('fft-then-ifft.png', ifft2.astype(np.uint8))