Display numpy ndarray as Image in Jupyter/IPython notebook

ipython_display.py

# if input image is in range 0..1, please first multiply img by 255
# assume image is ndarray of shape [height, width, channels] where channels can be 1, 3 or 4
def imshow(img):
    import cv2
    import IPython
    _,ret = cv2.imencode('.jpg', img) 
    i = IPython.display.Image(data=ret)
    IPython.display.display(i)

ipython_display_demo.ipynb

{
 "cells": [
  {
   "cell_type": "code",
   "execution_count": 1,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "image/png": "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\n",
      "text/plain": [
       "<IPython.core.display.Image object>"
      ]
     },
     "metadata": {},
     "output_type": "display_data"
    }
   ],
   "source": [
    "import numpy as np\n",
    "from ipython_display import imshow\n",
    "\n",
    "src = np.zeros((128, 128, 3))\n",
    "src+=0.2\n",
    "src[40:60, 60:100] += 0.3\n",
    "src[50:90, 20:70] += 0.2\n",
    "\n",
    "imshow(src*255)"
   ]
  }
 ],
 "metadata": {
  "kernelspec": {
   "display_name": "Python 3",
   "language": "python",
   "name": "python3"
  },
  "language_info": {
   "codemirror_mode": {
    "name": "ipython",
    "version": 3
   },
   "file_extension": ".py",
   "mimetype": "text/x-python",
   "name": "python",
   "nbconvert_exporter": "python",
   "pygments_lexer": "ipython3",
   "version": "3.5.2"
  }
 },
 "nbformat": 4,
 "nbformat_minor": 2
}

Thank you! Image shows directly in Jupyter Lab ❤️