- fixed accessing variable outside function

- refactored

ocv_corner_tracker.py

@@ -1,6 +1,7 @@
 import cv2
 import numpy as np
 import argparse
+import sys
 
 from util import image_crop, to_rect, bbox_add_position, bbox_center, bbox_round
 
@@ -143,8 +144,8 @@ class CornerTracker:
 
 	def init_reference_frame(self, _image: np.array):
 		# Draw mask
-		_mask = CornerTracker.mask_init(image)
-		CornerTracker.mask_draw(image, _mask)
+		_mask = CornerTracker.mask_init(_image)
+		CornerTracker.mask_draw(_image, _mask)
 
 		# Select search area
 		print(f"Select tracking object")
@@ -299,6 +300,7 @@ if __name__ == '__main__':
 	parser.add_argument("--scale", default=1.0)
 	parser.add_argument("--track", action="store_true")
 	parser.add_argument("--path", action="store_true")
+	parser.add_argument("--loop", action="store_true")
 	args = parser.parse_args()
 	video = cv2.VideoCapture(args.filename)
 
@@ -309,10 +311,15 @@ if __name__ == '__main__':
 	colors = [(255, 0, 0), (0, 255, 0), (0, 0, 255), (255, 0, 255), (0, 255, 255), (255, 255, 255)]
 	tracker_count = 0
 	tracker_list = []
-	if video.isOpened():
+	if not video.isOpened():
+		print('Cannot open video file')
+		sys.exit(1)
 	# Read first frame.
 	ok, image = video.read()
-		if ok:
+	if not ok:
+		print('Cannot read video file')
+		sys.exit(1)
+
 	for tracker_count in range(0, 6):
 		select_window = image.copy()
 		print(f"Draw tracker #{tracker_count}")
@@ -324,9 +331,6 @@ if __name__ == '__main__':
 		else:
 			break
 
-		else:
-			print('Cannot read video file')
-
 	# rewind to frame 0
 	video.set(cv2.CAP_PROP_POS_FRAMES, 0)
 
@@ -338,7 +342,13 @@ if __name__ == '__main__':
 		timer = cv2.getTickCount()
 		# Read a new frame
 		ok, image = video.read()
-			if ok:
+		if not ok:
+			if args.loop:
+				video.set(cv2.CAP_PROP_POS_FRAMES, 0)
+				continue
+			else:
+				break
+
 		image_anno = image.copy()
 		i = 0
 		cv2.rectangle(image_anno, (25, 0), (int(image_anno.shape[1]), 25*(1+len(tracker_list))), (0, 0, 0), -1)
@@ -362,9 +372,6 @@ if __name__ == '__main__':
 					cv2.FONT_HERSHEY_SIMPLEX, 0.5, (50, 170, 50), 1)
 
 		cv2.imshow(f"Image Anno", image_anno)
-			else:
-				video.set(cv2.CAP_PROP_POS_FRAMES, 0)
-				continue
 
 		# Exit if ESC pressed
 		k = cv2.waitKey(key_wait) & 0xff
@@ -376,5 +383,3 @@ if __name__ == '__main__':
 			else:
 				key_wait = -1
 
-	else:
-		print('Cannot open video file')