examples/notebooks/136_download_parallel.ipynb

{
 "cells": [
  {
   "cell_type": "markdown",
   "id": "0",
   "metadata": {},
   "source": [
    "<a href=\"https://githubtocolab.com/gee-community/geemap/blob/master/examples/notebooks/136_download_parallel.ipynb\" target=\"_parent\"><img src=\"https://colab.research.google.com/assets/colab-badge.svg\" alt=\"Open in Colab\"/></a>\n",
    "\n",
    "**Downloading Earth Engine images in parallel**\n",
    "\n",
    "Uncomment the following line to install [geemap](https://geemap.org) if needed."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "id": "1",
   "metadata": {},
   "outputs": [],
   "source": [
    "# !pip install -U geemap geedim"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "id": "2",
   "metadata": {},
   "outputs": [],
   "source": [
    "import ee\n",
    "import geemap"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "3",
   "metadata": {},
   "source": [
    "Add a Landsat imagery to the map"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "id": "4",
   "metadata": {},
   "outputs": [],
   "source": [
    "Map = geemap.Map(center=[40, -100], zoom=4)\n",
    "image = ee.Image(\"LANDSAT/LE7_TOA_5YEAR/1999_2003\").select([\"B4\", \"B3\", \"B2\"])\n",
    "Map.addLayer(image, {\"min\": 20, \"max\": 200, \"gamma\": 2.0}, \"Landsat\")\n",
    "Map"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "5",
   "metadata": {},
   "source": [
    "Specify a region of interest."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "id": "6",
   "metadata": {},
   "outputs": [],
   "source": [
    "region = ee.Geometry.BBox(-112.5439, 34.0891, -85.0342, 49.6858)\n",
    "Map.addLayer(region, {}, \"ROI\")\n",
    "Map.centerObject(region)"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "7",
   "metadata": {},
   "source": [
    "Create a fishnet."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "id": "8",
   "metadata": {},
   "outputs": [],
   "source": [
    "fishnet = geemap.fishnet(region, h_interval=4.0, v_interval=4.0, delta=0.5)"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "9",
   "metadata": {},
   "source": [
    "Add the fishnet to the map."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "id": "10",
   "metadata": {},
   "outputs": [],
   "source": [
    "style = {\"color\": \"ffff00ff\", \"fillColor\": \"00000000\"}\n",
    "Map.addLayer(fishnet.style(**style), {}, \"Fishnet\")"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "11",
   "metadata": {},
   "source": [
    "Download images by the fishnet cells in parallel."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "id": "12",
   "metadata": {},
   "outputs": [],
   "source": [
    "geemap.download_ee_image_tiles_parallel(\n",
    "    image, fishnet, out_dir=\"tiles\", scale=1000, crs=\"EPSG:3857\"\n",
    ")"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "13",
   "metadata": {},
   "source": [
    "The parallel downloading above takes ~10 seconds. The serial downloading below takes ~60 seconds."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "id": "14",
   "metadata": {},
   "outputs": [],
   "source": [
    "geemap.download_ee_image_tiles(\n",
    "    image, fishnet, out_dir=\"tiles\", scale=1000, crs=\"EPSG:3857\"\n",
    ")"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "15",
   "metadata": {},
   "source": [
    "![](https://i.imgur.com/L1IH3fq.png)"
   ]
  }
 ],
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