compute_smoothness.py

import sys 
import csv 

import numpy as np
from scipy.misc import imread


output_file = 'sharpnesses.txt'
imgs = sys.argv[1:]


with open(output_file, 'w', newline='') as csvfile:
    writer = csv.writer(csvfile, quoting=csv.QUOTE_MINIMAL)
    for img in imgs:
        im = imread(img).astype('float32') / 255.

        # We suppose a Latitude-Longitude format, so we remove the ground (bottom part)
        im = im[:np.round(im.shape[0]*0.47).astype('int'),:,:]

        im_grayscale = np.dot(im, [0.299, 0.587, 0.114])
        im_fft = np.abs(np.fft.fft2(im_grayscale))
        sharpness = np.sum(im_fft.ravel() > 5) / im_grayscale.size
        writer.writerow([img, sharpness])