{
 "cells": [
  {
   "cell_type": "code",
   "execution_count": 1,
   "metadata": {},
   "outputs": [],
   "source": [
    "import folium\n",
    "import matplotlib\n",
    "import numpy as np\n",
    "import branca\n",
    "from matplotlib.pyplot import imread\n",
    "from matplotlib.colors import Normalize\n",
    "from matplotlib.colors import ListedColormap\n",
    "from folium import raster_layers"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 2,
   "metadata": {},
   "outputs": [],
   "source": [
    "image = '/notebooks/resources/gpm/gpm_1d.20190531.tif'"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 3,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "10.0 -180.0\n",
      "-60.0 -180.0\n",
      "-60.0 -30.0\n",
      "10.0 -30.0\n",
      "ext = [[10.0, -180.0], [-60.0, -180.0], [-60.0, -30.0], [10.0, -30.0]]\n",
      "geo_ext = [[10.0, -180.0], [-60.0, -180.0], [-60.0, -30.0], [10.0, -30.0]]\n"
     ]
    }
   ],
   "source": [
    "from osgeo import gdal,ogr,osr\n",
    "\n",
    "def GetExtent(gt,cols,rows):\n",
    "    ''' Return list of corner coordinates from a geotransform\n",
    "\n",
    "        @type gt:   C{tuple/list}\n",
    "        @param gt: geotransform\n",
    "        @type cols:   C{int}\n",
    "        @param cols: number of columns in the dataset\n",
    "        @type rows:   C{int}\n",
    "        @param rows: number of rows in the dataset\n",
    "        @rtype:    C{[float,...,float]}\n",
    "        @return:   coordinates of each corner\n",
    "    '''\n",
    "    ext=[]\n",
    "    xarr=[0,cols]\n",
    "    yarr=[0,rows]\n",
    "\n",
    "    for px in xarr:\n",
    "        for py in yarr:\n",
    "            x=gt[0]+(px*gt[1])+(py*gt[2])\n",
    "            y=gt[3]+(px*gt[4])+(py*gt[5])\n",
    "            ext.append([y,x])\n",
    "            print (y,x)\n",
    "        yarr.reverse()\n",
    "    return ext\n",
    "\n",
    "def ReprojectCoords(coords,src_srs,tgt_srs):\n",
    "    ''' Reproject a list of x,y coordinates.\n",
    "\n",
    "        @type geom:     C{tuple/list}\n",
    "        @param geom:    List of [[x,y],...[x,y]] coordinates\n",
    "        @type src_srs:  C{osr.SpatialReference}\n",
    "        @param src_srs: OSR SpatialReference object\n",
    "        @type tgt_srs:  C{osr.SpatialReference}\n",
    "        @param tgt_srs: OSR SpatialReference object\n",
    "        @rtype:         C{tuple/list}\n",
    "        @return:        List of transformed [[x,y],...[x,y]] coordinates\n",
    "    '''\n",
    "    trans_coords=[]\n",
    "    transform = osr.CoordinateTransformation( src_srs, tgt_srs)\n",
    "    for x,y in coords:\n",
    "        x,y,z = transform.TransformPoint(x,y)\n",
    "        trans_coords.append([x,y])\n",
    "    return trans_coords\n",
    "\n",
    "raster=image\n",
    "ds=gdal.Open(raster)\n",
    "\n",
    "gt=ds.GetGeoTransform()\n",
    "cols = ds.RasterXSize\n",
    "rows = ds.RasterYSize\n",
    "\n",
    "ext=GetExtent(gt,cols,rows)\n",
    "print(\"ext = \" + str(ext))\n",
    "\n",
    "src_srs=osr.SpatialReference()\n",
    "src_srs.ImportFromWkt(ds.GetProjection())\n",
    "# tgt_srs=osr.SpatialReference()\n",
    "# tgt_srs.ImportFromEPSG(3857)\n",
    "tgt_srs = src_srs.CloneGeogCS()\n",
    "\n",
    "geo_ext=ReprojectCoords(ext,src_srs,tgt_srs)\n",
    "print(\"geo_ext = \" + str(geo_ext))"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 4,
   "metadata": {},
   "outputs": [],
   "source": [
    "# # Choose colormap\n",
    "# cmap = matplotlib.cm.cool\n",
    "\n",
    "# # Get the colormap colors\n",
    "# my_cmap = cmap(np.arange(cmap.N))\n",
    "\n",
    "\n",
    "# # Set alpha\n",
    "# my_cmap[:,-1] = np.linspace(0, 1, cmap.N)\n",
    "\n",
    "# # Create new colormap\n",
    "# my_cmap = ListedColormap(my_cmap)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 5,
   "metadata": {},
   "outputs": [],
   "source": [
    "# # Choose colormap\n",
    "# cmap = matplotlib.cm.cool\n",
    "\n",
    "# min_x = 0\n",
    "# max_x = 256\n",
    "\n",
    "# def my_cmap(x):\n",
    "#     x = np.clip((x - min_x)/(max_x - min_x), 0, 1)\n",
    "#     c = cmap(x)\n",
    "#     # multiplying alpha by 10 to make a sharper transition to the colors in the lower range\n",
    "#     return c[:3] + (np.clip(x*10, 0, 1),) "
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 10,
   "metadata": {},
   "outputs": [],
   "source": [
    "colormap = branca.colormap.StepColormap(\n",
    "    ['#64abb0','#9dd3a7', '#c7e9ad', '#edf8b9', '#ffedaa', '#fec980', '#f99e59', '#e85b3a', '#d7191c'],\n",
    "    vmin=0, vmax=10000,\n",
    "    index=[0, 25, 50, 100, 250, 500, 1000, 2500, 5000, 10000],\n",
    "    caption='step'\n",
    ")\n",
    "\n",
    "my_cmap = colormap\n",
    "\n",
    "# # Get the colormap colors\n",
    "# my_cmap = colormap(np.arange(colormap.N))\n",
    "\n",
    "\n",
    "# # Set alpha\n",
    "# my_cmap[:,-1] = np.linspace(0, 1, colormap.N)\n",
    "\n",
    "# # Create new colormap\n",
    "# my_cmap = ListedColormap(my_cmap)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 11,
   "metadata": {
    "scrolled": false
   },
   "outputs": [
    {
     "ename": "IndexError",
     "evalue": "tuple index out of range",
     "output_type": "error",
     "traceback": [
      "\u001b[0;31m---------------------------------------------------------------------------\u001b[0m",
      "\u001b[0;31mIndexError\u001b[0m                                Traceback (most recent call last)",
      "\u001b[0;32m<ipython-input-11-1cdfaf3b95d4>\u001b[0m in \u001b[0;36m<module>\u001b[0;34m\u001b[0m\n\u001b[1;32m     15\u001b[0m     \u001b[0;34m,\u001b[0m \u001b[0mbounds\u001b[0m \u001b[0;34m=\u001b[0m \u001b[0;34m[\u001b[0m\u001b[0mext\u001b[0m\u001b[0;34m[\u001b[0m\u001b[0;36m2\u001b[0m\u001b[0;34m]\u001b[0m\u001b[0;34m,\u001b[0m \u001b[0mext\u001b[0m\u001b[0;34m[\u001b[0m\u001b[0;36m0\u001b[0m\u001b[0;34m]\u001b[0m\u001b[0;34m]\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[1;32m     16\u001b[0m     \u001b[0;34m,\u001b[0m \u001b[0mmercator_project\u001b[0m \u001b[0;34m=\u001b[0m \u001b[0;32mTrue\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0;32m---> 17\u001b[0;31m     \u001b[0;34m,\u001b[0m \u001b[0mcolormap\u001b[0m \u001b[0;34m=\u001b[0m \u001b[0mmy_cmap\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0m\u001b[1;32m     18\u001b[0m )\n\u001b[1;32m     19\u001b[0m            )\n",
      "\u001b[0;32m/usr/local/lib/python3.5/dist-packages/folium/raster_layers.py\u001b[0m in \u001b[0;36m__init__\u001b[0;34m(self, image, bounds, origin, colormap, mercator_project, pixelated, name, overlay, control, show, **kwargs)\u001b[0m\n\u001b[1;32m    274\u001b[0m                 origin=origin)\n\u001b[1;32m    275\u001b[0m \u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0;32m--> 276\u001b[0;31m         \u001b[0mself\u001b[0m\u001b[0;34m.\u001b[0m\u001b[0murl\u001b[0m \u001b[0;34m=\u001b[0m \u001b[0mimage_to_url\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0mimage\u001b[0m\u001b[0;34m,\u001b[0m \u001b[0morigin\u001b[0m\u001b[0;34m=\u001b[0m\u001b[0morigin\u001b[0m\u001b[0;34m,\u001b[0m \u001b[0mcolormap\u001b[0m\u001b[0;34m=\u001b[0m\u001b[0mcolormap\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0m\u001b[1;32m    277\u001b[0m \u001b[0;34m\u001b[0m\u001b[0m\n\u001b[1;32m    278\u001b[0m         \u001b[0mself\u001b[0m\u001b[0;34m.\u001b[0m\u001b[0mbounds\u001b[0m \u001b[0;34m=\u001b[0m \u001b[0mjson\u001b[0m\u001b[0;34m.\u001b[0m\u001b[0mloads\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0mjson\u001b[0m\u001b[0;34m.\u001b[0m\u001b[0mdumps\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0mbounds\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n",
      "\u001b[0;32m/usr/local/lib/python3.5/dist-packages/folium/utilities.py\u001b[0m in \u001b[0;36mimage_to_url\u001b[0;34m(image, colormap, origin)\u001b[0m\n\u001b[1;32m    109\u001b[0m         \u001b[0murl\u001b[0m \u001b[0;34m=\u001b[0m \u001b[0;34m'data:image/{};base64,{}'\u001b[0m\u001b[0;34m.\u001b[0m\u001b[0mformat\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0mfileformat\u001b[0m\u001b[0;34m,\u001b[0m \u001b[0mb64encoded\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[1;32m    110\u001b[0m     \u001b[0;32melif\u001b[0m \u001b[0;34m'ndarray'\u001b[0m \u001b[0;32min\u001b[0m \u001b[0mimage\u001b[0m\u001b[0;34m.\u001b[0m\u001b[0m__class__\u001b[0m\u001b[0;34m.\u001b[0m\u001b[0m__name__\u001b[0m\u001b[0;34m:\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0;32m--> 111\u001b[0;31m         \u001b[0mimg\u001b[0m \u001b[0;34m=\u001b[0m \u001b[0mwrite_png\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0mimage\u001b[0m\u001b[0;34m,\u001b[0m \u001b[0morigin\u001b[0m\u001b[0;34m=\u001b[0m\u001b[0morigin\u001b[0m\u001b[0;34m,\u001b[0m \u001b[0mcolormap\u001b[0m\u001b[0;34m=\u001b[0m\u001b[0mcolormap\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0m\u001b[1;32m    112\u001b[0m         \u001b[0mb64encoded\u001b[0m \u001b[0;34m=\u001b[0m \u001b[0mbase64\u001b[0m\u001b[0;34m.\u001b[0m\u001b[0mb64encode\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0mimg\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m.\u001b[0m\u001b[0mdecode\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0;34m'utf-8'\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[1;32m    113\u001b[0m         \u001b[0murl\u001b[0m \u001b[0;34m=\u001b[0m \u001b[0;34m'data:image/png;base64,{}'\u001b[0m\u001b[0;34m.\u001b[0m\u001b[0mformat\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0mb64encoded\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n",
      "\u001b[0;32m/usr/local/lib/python3.5/dist-packages/folium/utilities.py\u001b[0m in \u001b[0;36mwrite_png\u001b[0;34m(data, origin, colormap)\u001b[0m\n\u001b[1;32m    172\u001b[0m     \u001b[0;32mif\u001b[0m \u001b[0mnblayers\u001b[0m \u001b[0;34m==\u001b[0m \u001b[0;36m1\u001b[0m\u001b[0;34m:\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[1;32m    173\u001b[0m         \u001b[0marr\u001b[0m \u001b[0;34m=\u001b[0m \u001b[0mnp\u001b[0m\u001b[0;34m.\u001b[0m\u001b[0marray\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0mlist\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0mmap\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0mcolormap\u001b[0m\u001b[0;34m,\u001b[0m \u001b[0marr\u001b[0m\u001b[0;34m.\u001b[0m\u001b[0mravel\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0;32m--> 174\u001b[0;31m         \u001b[0mnblayers\u001b[0m \u001b[0;34m=\u001b[0m \u001b[0marr\u001b[0m\u001b[0;34m.\u001b[0m\u001b[0mshape\u001b[0m\u001b[0;34m[\u001b[0m\u001b[0;36m1\u001b[0m\u001b[0;34m]\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0m\u001b[1;32m    175\u001b[0m         \u001b[0;32mif\u001b[0m \u001b[0mnblayers\u001b[0m \u001b[0;32mnot\u001b[0m \u001b[0;32min\u001b[0m \u001b[0;34m[\u001b[0m\u001b[0;36m3\u001b[0m\u001b[0;34m,\u001b[0m \u001b[0;36m4\u001b[0m\u001b[0;34m]\u001b[0m\u001b[0;34m:\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[1;32m    176\u001b[0m             raise ValueError('colormap must provide colors of r'\n",
      "\u001b[0;31mIndexError\u001b[0m: tuple index out of range"
     ]
    }
   ],
   "source": [
    "m = folium.Map(\n",
    "      location = [-22, -114]\n",
    "    , zoom_start = 2\n",
    "    , control_scale = True \n",
    "    , tiles = 'Stamen Terrain'\n",
    ")\n",
    "\n",
    "data = matplotlib.pyplot.imread(image)\n",
    "\n",
    "# Image bounds on the map in the form\n",
    "# [[lat_min, lon_min], [lat_max, lon_max]]\n",
    "m.add_child(raster_layers.ImageOverlay(\n",
    "      data\n",
    "    , opacity = 0.7\n",
    "    , bounds = [ext[2], ext[0]]\n",
    "    , mercator_project = True\n",
    "    , colormap = my_cmap\n",
    ")\n",
    "           )\n",
    "\n",
    "m"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": []
  }
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