This project never really took of, I'm not maintaining it and it's not likely to be very useful to you.
A simple plugin for powerful raster functions.
UNMAINTAINED This repo never reached more than proof-of-concept status, feel free to check it out for ideas, but don't expect it to work. Sorry.
This plugin makes it easy to add powerful raster processing to your Leaflet map, running directly in the browser. Examples can be hill shading, vegetation index analysis (NDVI for example) and much more.
The plugin by itself is very small and does very little. Its purpose is to function as the glue between Leaflet and powerful libraries like GeoTIFF.js and raster-blaster.
A small example using both GeoTIFF.js and raster-blaster:
import RasterLayer from 'leaflet-raster'
import GeoTIFF from 'geotiff'
import Pipeline from 'raster-blaster/src/pipeline'
import * as PipelineSteps from 'raster-blaster/src/pipeline-steps'
import WebGlRenderer from 'raster-blaster/src/webgl/webgl-renderer'
const pipeline = new Pipeline([
// VARI vegetation index
new PipelineSteps.GrayScale('($g - $r) / ($g + $r - $b)'),
// Stretch histogram to between index 0.2 to 0.8
new PipelineSteps.SmoothstepContrast(0.2, 0.8)
// Map grayscale to color scale Red-Yellow-Green
new PipelineSteps.ColorMap('RdYlGn'),
// Copy alpha band directly to alpha channel
new PipelineSteps.BandsToChannels('a')
],
{
bands: 'rgba',
dataType: 'Uint8'
})
const renderer = new WebGlRenderer()
const renderFn = (canvas, getRasters) => renderer.render(canvas, pipeline, getRasters)
GeoTIFF.fromUrl('data/ortho.tiff')
.then(tiff => {
const rasterFn = (nwSe, size) => tiff.readRasters({
bbox: [nwSe[0].lng, nwSe[1].lat, nwSe[1].lng, nwSe[0].lat],
width: size.x,
height: size.y
})
// RasterLayer ties the raster function (GeoTIFF.js) and
// render function (raster-blaster) together
const geotiffLayer = new RasterLayer(tiff, rasterFn, renderFn)
L.map('map', {
maxZoom: 26,
layers: [geotiffLayer]
})
.fitBounds([[57.3066538, 12.3338591], [57.3089762, 12.3387167]])