distance_from_camera.ipynb

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    {
     "ename": "ValueError",
     "evalue": "not enough values to unpack (expected 3, got 2)",
     "output_type": "error",
     "traceback": [
      "\u001b[0;31m---------------------------------------------------------------------------\u001b[0m",
      "\u001b[0;31mValueError\u001b[0m                                Traceback (most recent call last)",
      "\u001b[0;32m<ipython-input-1-7137fa2d2736>\u001b[0m in \u001b[0;36m<module>\u001b[0;34m\u001b[0m\n\u001b[1;32m     63\u001b[0m \u001b[0;34m\u001b[0m\u001b[0m\n\u001b[1;32m     64\u001b[0m     \u001b[0;31m#find the histogram\u001b[0m\u001b[0;34m\u001b[0m\u001b[0;34m\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0;32m---> 65\u001b[0;31m     \u001b[0m_\u001b[0m\u001b[0;34m,\u001b[0m\u001b[0mcont\u001b[0m\u001b[0;34m,\u001b[0m\u001b[0mhei\u001b[0m \u001b[0;34m=\u001b[0m \u001b[0mcv2\u001b[0m\u001b[0;34m.\u001b[0m\u001b[0mfindContours\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0md_img\u001b[0m\u001b[0;34m,\u001b[0m\u001b[0mcv2\u001b[0m\u001b[0;34m.\u001b[0m\u001b[0mRETR_EXTERNAL\u001b[0m\u001b[0;34m,\u001b[0m\u001b[0mcv2\u001b[0m\u001b[0;34m.\u001b[0m\u001b[0mCHAIN_APPROX_SIMPLE\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0m\u001b[1;32m     66\u001b[0m     \u001b[0mcont\u001b[0m \u001b[0;34m=\u001b[0m \u001b[0msorted\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0mcont\u001b[0m\u001b[0;34m,\u001b[0m \u001b[0mkey\u001b[0m \u001b[0;34m=\u001b[0m \u001b[0mcv2\u001b[0m\u001b[0;34m.\u001b[0m\u001b[0mcontourArea\u001b[0m\u001b[0;34m,\u001b[0m \u001b[0mreverse\u001b[0m \u001b[0;34m=\u001b[0m \u001b[0;32mTrue\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m[\u001b[0m\u001b[0;34m:\u001b[0m\u001b[0;36m1\u001b[0m\u001b[0;34m]\u001b[0m\u001b[0;34m\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[1;32m     67\u001b[0m \u001b[0;34m\u001b[0m\u001b[0m\n",
      "\u001b[0;31mValueError\u001b[0m: not enough values to unpack (expected 3, got 2)"
     ]
    }
   ],
   "source": [
    "import numpy as np\n",
    "import cv2\n",
    "\n",
    "\n",
    "#Define object specific variables  \n",
    "dist = 0\n",
    "focal = 450\n",
    "pixels = 30\n",
    "width = 4\n",
    "\n",
    "\n",
    "#find the distance from then camera\n",
    "def get_dist(rectange_params,image):\n",
    "    #find no of pixels covered\n",
    "    pixels = rectange_params[1][0]\n",
    "    print(pixels)\n",
    "    #calculate distance\n",
    "    dist = (width*focal)/pixels\n",
    "    \n",
    "    #Wrtie n the image\n",
    "    image = cv2.putText(image, 'Distance from Camera in CM :', org, font,  \n",
    "       1, color, 2, cv2.LINE_AA)\n",
    "\n",
    "    image = cv2.putText(image, str(dist), (110,50), font,  \n",
    "       fontScale, color, 1, cv2.LINE_AA)\n",
    "\n",
    "    return image\n",
    "\n",
    "#Extract Frames \n",
    "cap = cv2.VideoCapture(0)\n",
    "\n",
    "\n",
    "#basic constants for opencv Functs\n",
    "kernel = np.ones((3,3),'uint8')\n",
    "font = cv2.FONT_HERSHEY_SIMPLEX \n",
    "org = (0,20)  \n",
    "fontScale = 0.6 \n",
    "color = (0, 0, 255) \n",
    "thickness = 2\n",
    "\n",
    "\n",
    "cv2.namedWindow('Object Dist Measure ',cv2.WINDOW_NORMAL)\n",
    "cv2.resizeWindow('Object Dist Measure ', 700,600)\n",
    "\n",
    "\n",
    "#loop to capture video frames\n",
    "while True:\n",
    "    ret, img = cap.read()\n",
    "\n",
    "    hsv_img = cv2.cvtColor(img,cv2.COLOR_BGR2HSV)\n",
    "\n",
    "\n",
    "    #predefined mask for green colour detection\n",
    "    lower = np.array([37, 51, 24])\n",
    "    upper = np.array([83, 104, 131])\n",
    "    mask = cv2.inRange(hsv_img, lower, upper)\n",
    "     \n",
    "\n",
    "\n",
    "    #Remove Extra garbage from image\n",
    "    d_img = cv2.morphologyEx(mask, cv2.MORPH_OPEN, kernel,iterations = 5)\n",
    "\n",
    "\n",
    "    #find the histogram\n",
    "    _,cont,hei = cv2.findContours(d_img,cv2.RETR_EXTERNAL,cv2.CHAIN_APPROX_SIMPLE)\n",
    "    cont = sorted(cont, key = cv2.contourArea, reverse = True)[:1]\n",
    "\n",
    "    for cnt in cont:\n",
    "        #check for contour area\n",
    "        if (cv2.contourArea(cnt)>100 and cv2.contourArea(cnt)<306000):\n",
    "\n",
    "            #Draw a rectange on the contour\n",
    "            rect = cv2.minAreaRect(cnt)\n",
    "            box = cv2.boxPoints(rect) \n",
    "            box = np.int0(box)\n",
    "            cv2.drawContours(img,[box], -1,(255,0,0),3)\n",
    "            \n",
    "            img = get_dist(rect,img)\n",
    "\n",
    "    cv2.imshow('Object Dist Measure ',img)\n",
    "\n",
    "    if cv2.waitKey(1) & 0xFF == ord('q'):\n",
    "        break\n",
    "\n",
    "cv2.destroyAllWindows()"
   ]
  }
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