Higuruma - COG Tiler on Hono

• Hono -> Hi(火🔥)
• Cloud Optimized GeoTIFF(COG) -> gear -> Haguruma(歯車⚙️)

motivation

• geomatico/maplibre-cog-protocol is amazing work to consume COG on browser, maximizing performance of geotiff.js and provides utilities to colorize raster data.
• It is also good the process to load COG and tiling them on server in terms of utilize shared cache.

usage

As Library

npm install higuruma

import { renderTile, locationValues } from 'higuruma/dist/index.esm.js'; // ES Module
// const { renderTile, locationValues } = require('higuruma/dist/index.cjs.js'); // CommonJS

const tile = await renderTile('https://path/to/cog.tif', z, x, y); // ArrayBuffer of PNG
const values = await locationValues('https://path/to/cog.tif', {latitude, longitude}); // pixel values

AWS Lambda

npm install
npm run deploy # needs credentials

endpoints

• /tile/{z}/{x}/{y}?url=https://path/to/cog.tif: content-type is image/png
• /values?url=https://path/to/cog.tif&lat=35.681236&lon=139.767125: return pixel value at the given lat/lon

inspired by developmentseed/titiler

acknowledgements

• This codes includes many codes derived from geomatico/maplibre-cog-protocol, modified to fit on Node.js.