hdrify

Universal EXR, HDR, and gain map image library for Node.js and browsers. Read and write HDR (Radiance RGBE), EXR (OpenEXR), and JPEG with gain maps (JPEG-R / Ultra HDR) in pure JavaScript. No native bindings.

Related packages: hdrify-cli (CLI tool) · hdrify-react (React component)

Features

• Read and write RGB EXR files (PIZ, PXR24, ZIP, ZIPS, and RLE compression)
• Read and write HDR (Radiance RGBE) files
• Read and write both Adobe Gain Map JPEGs and Ultra HDR JPEGs (Android compatible)
• Tone mappers (ACES, Khronos Neutral, AgX, Reinhard)
• Full TypeScript support
• No DOM or Node.js dependencies (works in browser, web workers, and Node.js)
• Written in a functional style to support tree-shaking

Installation

pnpm add hdrify

HdrifyImage

All read functions return HdrifyImage, and all write functions accept it. This is the universal intermediate format.

interface HdrifyImage {
  width: number;
  height: number;
  data: Float32Array;     // RGBA: [R, G, B, A, R, G, B, A, ...]
  linearColorSpace: LinearColorSpace;
  metadata?: Record<string, unknown>;
}

Usage

Reading an EXR file

import { readExr } from 'hdrify';

const buffer = fs.readFileSync('image.exr');
const image = readExr(new Uint8Array(buffer));

console.log(`Image: ${image.width}x${image.height}`);

Reading an HDR file

import { readHdr } from 'hdrify';

const buffer = fs.readFileSync('image.hdr');
const image = readHdr(new Uint8Array(buffer));

Reading a JPEG gain map (JPEG-R / Ultra HDR)

import { readJpegGainMap } from 'hdrify';

const buffer = fs.readFileSync('image.jpg');
const image = readJpegGainMap(new Uint8Array(buffer));
// image.data is linear HDR Float32Array RGBA; metadata.format is 'ultrahdr' or 'adobe-gainmap'

Converting between formats

import { encodeGainMap, readExr, writeExr, readHdr, writeHdr, writeJpegGainMap } from 'hdrify';

const image = readExr(new Uint8Array(fs.readFileSync('input.exr')));
fs.writeFileSync('output.hdr', writeHdr(image));

const encoding = encodeGainMap(image, { toneMapping: 'reinhard' });
fs.writeFileSync('output.jpg', writeJpegGainMap(encoding, { quality: 90 }));

License

MIT

Author

Ben Houston, Sponsored by Land of Assets