add -s option to override default camera resolution

canny.py

@@ -38,6 +38,12 @@
     type=float,
     help="rescale image by this factor",
     default=1.0)
+parser.add_argument(
+    "-s",
+    "--set_resolution",
+    type=int,
+    nargs=2,
+    help='override default camera resolution as H W')
 parser.add_argument(
     'video_file',
     metavar='video_file',
@@ -107,6 +113,12 @@ def nothing(x):
     sobel_size = 3  # greater than 7 seems to crash
     cv2.createTrackbar("sobel size", window_name2, sobel_size, 7, nothing)
 
+    # override default camera resolution
+
+    if not(args.set_resolution is None):
+        cap.set(cv2.CAP_PROP_FRAME_HEIGHT, args.set_resolution[1])
+        cap.set(cv2.CAP_PROP_FRAME_WIDTH, args.set_resolution[0])
+
     while (keep_processing):
 
         # if video file successfully open then read frame from video