Various Python samples updated for Python 2/3 compatibility.

samples/python2/coherence.py

@@ -9,6 +9,14 @@ inspired by
   http://www.mia.uni-saarland.de/Publications/weickert-dagm03.pdf
 '''
 
+# Python 2/3 compatibility
+from __future__ import print_function
+import sys
+PY3 = sys.version_info[0] == 3
+
+if PY3:
+    xrange = range
+
 import numpy as np
 import cv2
 
@@ -16,7 +24,7 @@ def coherence_filter(img, sigma = 11, str_sigma = 11, blend = 0.5, iter_n = 4):
     h, w = img.shape[:2]
 
     for i in xrange(iter_n):
-        print i,
+        print(i)
 
         gray = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)
         eigen = cv2.cornerEigenValsAndVecs(gray, str_sigma, 3)
@@ -34,7 +42,7 @@ def coherence_filter(img, sigma = 11, str_sigma = 11, blend = 0.5, iter_n = 4):
         img1 = ero
         img1[m] = dil[m]
         img = np.uint8(img*(1.0 - blend) + img1*blend)
-    print 'done'
+    print('done')
     return img
 
 
@@ -54,7 +62,7 @@ if __name__ == '__main__':
         sigma = cv2.getTrackbarPos('sigma', 'control')*2+1
         str_sigma = cv2.getTrackbarPos('str_sigma', 'control')*2+1
         blend = cv2.getTrackbarPos('blend', 'control') / 10.0
-        print 'sigma: %d  str_sigma: %d  blend_coef: %f' % (sigma, str_sigma, blend)
+        print('sigma: %d  str_sigma: %d  blend_coef: %f' % (sigma, str_sigma, blend))
         dst = coherence_filter(src, sigma=sigma, str_sigma = str_sigma, blend = blend)
         cv2.imshow('dst', dst)
 
@@ -64,7 +72,7 @@ if __name__ == '__main__':
     cv2.createTrackbar('str_sigma', 'control', 9, 15, nothing)
 
 
-    print 'Press SPACE to update the image\n'
+    print('Press SPACE to update the image\n')
 
     cv2.imshow('src', src)
     update()