Source code:

[python]
import cv2
import numpy as np

img = cv2.imread("gray_cover.jpg")
roi = img[252: 395, 354: 455]
x = 354
y = 252
width = 455 – x
height = 395 – y
hsv_roi = cv2.cvtColor(roi, cv2.COLOR_BGR2HSV)
roi_hist = cv2.calcHist([hsv_roi], [0], None, [180], [0, 180])

cap = cv2.VideoCapture(0)

term_criteria = (cv2.TERM_CRITERIA_EPS | cv2.TERM_CRITERIA_COUNT, 10, 1)

while True:
_, frame = cap.read()
hsv = cv2.cvtColor(frame, cv2.COLOR_BGR2HSV)
mask = cv2.calcBackProject([hsv], [0], roi_hist, [0, 180], 1)

ret, track_window = cv2.CamShift(mask, (x, y, width, height), term_criteria)

pts = cv2.boxPoints(ret)
pts = np.int0(pts)
cv2.polylines(frame, [pts], True, (255, 0, 0), 2)

cv2.imshow("mask", mask)
cv2.imshow("Frame", frame)

key = cv2.waitKey(1)
if key == 27:
break

cap.release()
cv2.destroyAllWindows()
[/python]

 

Files:

  1. gray_cover.jpg