From a79517c136427f1982fbbc47dbd343806c176654 Mon Sep 17 00:00:00 2001
From: Jens Ahrensfeld <jens@jayfield.org>
Date: Sun, 30 Jun 2024 13:24:17 +0200
Subject: [PATCH] - refactored - draw path

---
 ocv_track.py | 42 +++++++++++++++++++++++-------------------
 1 file changed, 23 insertions(+), 19 deletions(-)

diff --git a/ocv_track.py b/ocv_track.py
index 94ebd3e..3f2056e 100644
--- a/ocv_track.py
+++ b/ocv_track.py
@@ -4,23 +4,12 @@ import numpy as np
 import imutils as im
 
 IMG_SCALE_UP = 4
-TEMPLATE_SEARCH_AREA = 0.8
+TEMPLATE_SEARCH_AREA = 0.5
 
 (major_ver, minor_ver, subminor_ver) = cv2.__version__.split('.')
 print(cv2.__version__)
 
 
-def bbox_extend(bbox: cv2.typing.Rect, search_area: float):
-	we2 = int(round(bbox[2]*search_area/2))
-	he2 = int(round(bbox[3]*search_area/2))
-	res = (int(round(bbox[0]-we2)),)
-	res += (int(round(bbox[1]-he2)),)
-	res += (int(bbox[2]+2*we2),)
-	res += (int(bbox[3]+2*he2),)
-
-	return res
-
-
 def bbox_round(src):
 	x = int(round(src[0]))
 	y = int(round(src[1]))
@@ -30,10 +19,14 @@ def bbox_round(src):
 	return x, y, w, h
 
 
-def image_crop(src, bbox: cv2.typing.Rect, search_area: float = 0):
-	if search_area > 0:
-		bbox = bbox_extend(bbox, search_area)
+def bbox_extend(bbox: cv2.typing.Rect, factor: float = 0):
+	we2 = bbox[2]*factor/2
+	he2 = bbox[3]*factor/2
 
+	return bbox_round((bbox[0]-we2, bbox[1]-he2, bbox[2]+2*we2, bbox[3]+2*he2))
+
+
+def image_crop(src, bbox: cv2.typing.Rect):
 	x = bbox[0]
 	y = bbox[1]
 	w = bbox[2]
@@ -137,22 +130,26 @@ if not video.isOpened():
 	sys.exit()
 
 # Read first frame.
-ok, frame = video.read()
+ok, frame_init = video.read()
 if not ok:
 	print('Cannot read video file')
 	sys.exit()
 
-bbox = cv2.selectROI("Frame", frame, False)
-image_template = process_image_bbox(image_crop(frame, bbox, TEMPLATE_SEARCH_AREA))
+bbox_init = cv2.selectROI("Frame", frame_init, False)
+bbox_template = bbox_extend(bbox_init, TEMPLATE_SEARCH_AREA)
+image_template = process_image_bbox(image_crop(frame_init, bbox_template))
 ref = Reference(image_template)
 ref_center = ref.set()
 
 print(f"ref_center = {ref_center}")
 # Initialize tracker with first frame and bounding box
 tracker.create()
-tracker.init(frame, bbox)
+tracker.init(frame_init, bbox_init)
 
 current_angle = 0
+line_from = (ref_center[0] + bbox_template[0], ref_center[1] + bbox_template[1])
+
+
 while True:
 	# Read a new frame
 	ok, frame = video.read()
@@ -185,6 +182,12 @@ while True:
 
 		# Calculate Frames per second (FPS)
 		fps = cv2.getTickFrequency() / (cv2.getTickCount() - timer)
+
+		# Draw path
+		line_to = (round(startX + bbox[0]), round(startY + bbox[1]))
+		cv2.line(frame_init, line_from, line_to, (0, 0, 255), 2)
+		line_from = line_to
+
 	else:
 		# Tracking failure
 		cv2.putText(frame, "Tracking failure detected", (100, 80), cv2.FONT_HERSHEY_SIMPLEX, 0.75, (0, 0, 255), 2)
@@ -196,6 +199,7 @@ while True:
 	cv2.putText(frame, "FPS : " + str(int(fps)), (100, 50), cv2.FONT_HERSHEY_SIMPLEX, 0.75, (50, 170, 50), 2)
 
 	# Display result
+	cv2.imshow("Path", frame_init)
 	cv2.imshow("Tracking", frame)
 	cv2.imshow("image_bbox", image_template_rotated)