Fixed shebangs, added error checking

samples/python2/browse.py

@@ -1,4 +1,4 @@
-#/usr/bin/env python
+#!/usr/bin/env python
 
 '''
 browse.py
@@ -14,6 +14,8 @@ browse.py [image filename]
 
 import numpy as np
 import cv2
+
+# built-in modules
 import sys
 
 if __name__ == '__main__':
@@ -25,6 +27,10 @@ if __name__ == '__main__':
         fn = sys.argv[1]
         print 'loading %s ...' % fn
         img = cv2.imread(fn)
+        if img is None:
+            print 'Failed to load fn:', fn
+            sys.exit(1)
+
     else:
         sz = 4096
         print 'generating %dx%d procedural image ...' % (sz, sz)
@@ -33,6 +39,7 @@ if __name__ == '__main__':
         track = np.int32(track*10 + (sz/2, sz/2))
         cv2.polylines(img, [track], 0, 255, 1, cv2.CV_AA)
 
+
     small = img
     for i in xrange(3):
         small = cv2.pyrDown(small)