fast-geotiff

Description

FastGeoTIFF is a layer over GeoTIFF.js (https://geotiffjs.github.io/) optimized for high performance raster reads of commonly formatted GeoTIFFs. For many common non-tiled, planar, RAW or LZW compressed GeoTIFFs, FastGeoTIFF can decode an ImageData of the rasters 5-10x faster than GeoTIFF.js.

E.g. a 150MB LZW compressed GeoTIFF can be decoded to ImageData in ~1s.

If FastGeoTIFF can't read the file, it will fall back to the (bundled) copy of GeoTIFF.js.

Uncompressed GeoTIFFs are 'read' using a direct mmap. LZW compressed GeoTIFFs are decoded using 'fast-lzw' (https://github.com/ceresimaging/fast-lzw), which uses web assembly for performance.

import { readRasterFromURL } from 'fast-geotiff'
 
// Load the ImageData from a URL (an arraybuffer version also exists)
const imageData = await readRasterFromURL('http://server.com/some-image.tiff')
 
// Draw it to an <img>
const canvas = new OffscreenCanvas(imageData.width, imageData.height)
canvas.getContext("2d").putImageData(imageData, 0, 0)
const dataURL = canvas.getDataURL()
const img = document.createElement("img")
img.setAttribute("src", canvas.getDataURL())
document.appendChild(img)