Magic Pen.ipynb

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   "source": [
    "#Importing Necessary projects\n",
    "import cv2\n",
    "import numpy as np"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 4,
   "metadata": {},
   "outputs": [],
   "source": [
    "#Creating the video capture object \n",
    "cap = cv2.VideoCapture(0)\n",
    "\n",
    "#Defining upper and lower ranges for yellow color\n",
    "Lower = np.array([20, 100, 100])\n",
    "Upper = np.array([30, 255, 255])\n",
    "\n",
    "#Defining kernel for Morphological operators\n",
    "kernel = np.ones((5,5),np.uint8)\n",
    "#Defining starting point\n",
    "x0,y0 = -1,-1\n",
    "\n",
    "\n",
    "#Creating an empty image / white background with the same frame size\n",
    "temp = np.ones((480, 640, 3),dtype = np.uint8)\n",
    "temp = temp*255\n",
    "\n",
    "while True:\n",
    "        ret,frame = cap.read()\n",
    "        s = frame.shape\n",
    "        #Flipping for mirror image\n",
    "        frame = cv2.flip(frame,1)\n",
    "        #Getting a hsv version of the frame for easy colour detection and locating the mask\n",
    "        hsv = cv2.cvtColor(frame,cv2.COLOR_BGR2HSV)\n",
    "        mask = cv2.inRange(hsv,Lower,Upper)\n",
    "        #Performing morphological operators \n",
    "        mask = cv2.erode(mask,kernel,iterations = 2)\n",
    "        final = cv2.morphologyEx(mask,cv2.MORPH_OPEN,kernel)\n",
    "        final  = cv2.dilate(mask,kernel,iterations = 1)\n",
    "\n",
    "        #Finding contours in the mask \n",
    "        contours,_ = cv2.findContours(final,cv2.RETR_EXTERNAL,cv2.CHAIN_APPROX_NONE)\n",
    "        #Getting the largest contours assuming it would be the object of interest\n",
    "        if contours:\n",
    "            cnt = max(contours,key = cv2.contourArea)\n",
    "            x,y,width,height = cv2.boundingRect(cnt)\n",
    "\n",
    "            if x0 == -1:\n",
    "                x0,y0 = x+width//2,y+height//2\n",
    "            else:\n",
    "                #Drawing on the temporary masked image\n",
    "                temp = cv2.line(temp,(x0,y0),(x+width//2,y+height//2),(0,0,255),5)\n",
    "    #             cv2.circle(frame,(x,y),5,2)\n",
    "                #To track can be removed if necessary \n",
    "                frame = cv2.line(frame,(x0,y0),(x+width//2,y+height//2),(255,255,255),5)\n",
    "                x0,y0 = x+width//2,y+height//2\n",
    "        else:\n",
    "            x0,y0=-1,-1\n",
    "            \n",
    "        # Operations using bitwise functions for the written stuff on the Result image\n",
    "        temp_gray = cv2.cvtColor(temp,cv2.COLOR_BGR2GRAY)  # BLACK FOREGROUND AND WHITE BACKGROUND\n",
    "        temp_gray_inv = cv2.bitwise_not(temp_gray) #WHITE FOREGROUND AND BLACK BACKGROUND\n",
    "        white_background = np.full(temp.shape, 255, dtype=np.uint8)  #Plain white background\n",
    "        bk = cv2.bitwise_or(white_background, white_background, mask=temp_gray_inv) #3 channeled temp_gray_inv\n",
    "        fg = cv2.bitwise_or(temp, temp, mask=temp_gray_inv) #Red foreground and black background\n",
    "        Result = cv2.bitwise_or(frame,fg)\n",
    "#         cv2.imshow('Main',frame)\n",
    "#         cv2.imshow('Mask',mask)\n",
    "#         cv2.imshow('Temp',temp)\n",
    "#         cv2.imshow('Tempgrayinv',temp_gray_inv)\n",
    "        cv2.imshow('Result',Result)\n",
    "        #To end the program\n",
    "        key  = cv2.waitKey(1) & 0xFF\n",
    "        if key == 27:\n",
    "            break\n",
    "            \n",
    "            \n",
    "        \n",
    "cap.release()\n",
    "cv2.destroyAllWindows()\n"
   ]
  }
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