georaster-layer-for-leaflet

Display GeoTIFFs and soon other types of rasters on your Leaflet Map

Install

npm install georaster-layer-for-leaflet

Load Package via Script Tag

<script src="https://unpkg.com/georaster-layer-for-leaflet/georaster-layer-for-leaflet.browserify.min.js"></script>

Usage

new GeoRasterLayer({georaster: georaster}).addTo(map);

Demo

https://geotiff.github.io/georaster-layer-for-leaflet-example/

Why

• Super faster rendering thanks to a simple nearest neighbor interpolation
• Use of web workers means seamless integration that doesn't block main thread
• Loads large geotiffs greater than a hundred megabytes

Longer Usage Example

Source Code: https://github.com/GeoTIFF/georaster-layer-for-leaflet-example/blob/master/main.js

var parse_georaster = require("georaster");

var GeoRasterLayer = require("georaster-layer-for-leaflet");

// initalize leaflet map
var map = L.map('map').setView([0, 0], 5);

// add OpenStreetMap basemap
L.tileLayer('http://{s}.tile.osm.org/{z}/{x}/{y}.png', {
    attribution: '&copy; <a href="http://osm.org/copyright">OpenStreetMap</a> contributors'
}).addTo(map);

var url_to_geotiff_file = "example_4326.tif";

fetch(url_to_geotiff_file)
  .then(response => response.arrayBuffer())
  .then(arrayBuffer => {
    parse_georaster(arrayBuffer).then(georaster => {
      console.log("georaster:", georaster);

      /*
          GeoRasterLayer is an extension of GridLayer,
          which means can use GridLayer options like opacity.

          Just make sure to include the georaster option!

          Optionally set the pixelValueToColorFn function option to customize
          how a pixel value is translated to a color.

          http://leafletjs.com/reference-1.2.0.html#gridlayer
      */
      var layer = new GeoRasterLayer({
          georaster: georaster,
          opacity: 0.7,
          pixelValueToColorFn: value => value === 42 ? '#ffffff' : '#000000'
      });
      layer.addTo(map);

      map.fitBounds(layer.getBounds());

  });
});

Support

Contact the package author, Daniel J. Dufour, at [email protected]