02-CamShift-Tracking.ipynb

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    "<a href=\"https://www.pieriandata.com\"><img src=\"../DATA/Logo.jpg\"></a>\n",
    "*Copyright Pierian Data Inc.*"
   ]
  },
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   "cell_type": "markdown",
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   "source": [
    "# CamShift Tracking"
   ]
  },
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   "source": [
    "import numpy as np\n",
    "import cv2 \n",
    "\n",
    "# Capture a video stream\n",
    "cap = cv2.VideoCapture(0)\n",
    "\n",
    "# take first frame of the video\n",
    "ret,frame = cap.read()\n",
    "\n",
    "\n",
    "# Set Up the Initial Tracking Window\n",
    "\n",
    "\n",
    "# We will first detect the face and set that as our starting box.\n",
    "face_cascade = cv2.CascadeClassifier('../DATA/haarcascades/haarcascade_frontalface_default.xml')\n",
    "face_rects = face_cascade.detectMultiScale(frame) \n",
    "\n",
    "# Convert this list of a single array to a tuple of (x,y,w,h)\n",
    "(face_x,face_y,w,h) = tuple(face_rects[0]) \n",
    "track_window = (face_x,face_y,w,h)\n",
    "# set up the ROI for tracking\n",
    "roi = frame[face_y:face_y+h, face_x:face_x+w]\n",
    "\n",
    "\n",
    "# Use the HSV Color Mapping\n",
    "hsv_roi =  cv2.cvtColor(roi, cv2.COLOR_BGR2HSV)\n",
    "\n",
    "# Find histogram to backproject the target on each frame for calculation of meanshit\n",
    "roi_hist = cv2.calcHist([hsv_roi],[0],None,[180],[0,180])\n",
    "\n",
    "# Normalize the histogram array values given a min of 0 and max of 255\n",
    "cv2.normalize(roi_hist,roi_hist,0,255,cv2.NORM_MINMAX)\n",
    "\n",
    "\n",
    "# Setup the termination criteria, either 10 iteration or move by at least 1 pt\n",
    "term_crit = ( cv2.TERM_CRITERIA_EPS | cv2.TERM_CRITERIA_COUNT, 10, 1 )\n",
    "\n",
    "while True:\n",
    "    ret ,frame = cap.read()\n",
    "    if ret == True:\n",
    "        \n",
    "        # Grab the Frame in HSV\n",
    "        hsv = cv2.cvtColor(frame, cv2.COLOR_BGR2HSV)\n",
    "        \n",
    "        # Calculate the Back Projection based off the roi_hist created earlier\n",
    "        dst = cv2.calcBackProject([hsv],[0],roi_hist,[0,180],1)\n",
    "        \n",
    "        #########################################################\n",
    "        #########################################################\n",
    "        ########## CAM SHIFT ####################################\n",
    "        ########################################################\n",
    "        #######################################################\n",
    "        \n",
    "        # Apply Camshift to get the new coordinates of the rectangle\n",
    "        ret, track_window = cv2.CamShift(dst, track_window, term_crit)\n",
    "        \n",
    "        # Draw it on image\n",
    "        pts = cv2.boxPoints(ret)\n",
    "        pts = np.int0(pts)\n",
    "        img2 = cv2.polylines(frame,[pts],True, (0,0,255),5)\n",
    "        cv2.imshow('img2',img2)\n",
    "        \n",
    "        ########################################################\n",
    "        #######################################################\n",
    "        ########################################################\n",
    "        #######################################################\n",
    "        \n",
    "        k = cv2.waitKey(1) & 0xff\n",
    "        if k == 27:\n",
    "            break\n",
    "        \n",
    "    else:\n",
    "        break\n",
    "        \n",
    "cv2.destroyAllWindows()\n",
    "cap.release()"
   ]
  }
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