Lecture 3.7 - Arithmetic Operations.ipynb

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    "## Arithmetic Operations\n",
    "\n",
    "These are simple operations that allow us to directly add or subract to the color intensity.\n",
    "\n",
    "Calculates the per-element operation of two arrays. The overall effect is increasing or decreasing brightness."
   ]
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     "text": [
      "(830L, 1245L, 3L)\n"
     ]
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   "source": [
    "import cv2\n",
    "import numpy as np\n",
    "\n",
    "image = cv2.imread('images/input.jpg')\n",
    "height = image.shape[0]\n",
    "width = image.shape[1]\n",
    "depth  = image.shape[2]\n",
    "\n",
    "M = np.ones([height,width, depth], dtype=\"uint8\")*25\n",
    "\n",
    "added = cv2.add(image,M)\n",
    "\n",
    "cv2.imshow('added', added)\n",
    "cv2.waitKey(0)\n",
    "cv2.destroyAllWindows()\n",
    "\n",
    "subtracted = cv2.subtract('')\n"
   ]
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       "array([[[75, 75, 75],\n",
       "        [75, 75, 75],\n",
       "        [75, 75, 75],\n",
       "        ..., \n",
       "        [75, 75, 75],\n",
       "        [75, 75, 75],\n",
       "        [75, 75, 75]],\n",
       "\n",
       "       [[75, 75, 75],\n",
       "        [75, 75, 75],\n",
       "        [75, 75, 75],\n",
       "        ..., \n",
       "        [75, 75, 75],\n",
       "        [75, 75, 75],\n",
       "        [75, 75, 75]],\n",
       "\n",
       "       [[75, 75, 75],\n",
       "        [75, 75, 75],\n",
       "        [75, 75, 75],\n",
       "        ..., \n",
       "        [75, 75, 75],\n",
       "        [75, 75, 75],\n",
       "        [75, 75, 75]],\n",
       "\n",
       "       ..., \n",
       "       [[75, 75, 75],\n",
       "        [75, 75, 75],\n",
       "        [75, 75, 75],\n",
       "        ..., \n",
       "        [75, 75, 75],\n",
       "        [75, 75, 75],\n",
       "        [75, 75, 75]],\n",
       "\n",
       "       [[75, 75, 75],\n",
       "        [75, 75, 75],\n",
       "        [75, 75, 75],\n",
       "        ..., \n",
       "        [75, 75, 75],\n",
       "        [75, 75, 75],\n",
       "        [75, 75, 75]],\n",
       "\n",
       "       [[75, 75, 75],\n",
       "        [75, 75, 75],\n",
       "        [75, 75, 75],\n",
       "        ..., \n",
       "        [75, 75, 75],\n",
       "        [75, 75, 75],\n",
       "        [75, 75, 75]]], dtype=uint8)"
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   "source": [
    "M = np.ones(image.shape, dtype = \"uint8\") * 75 \n",
    "M"
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