bytecut-ssimulacra2

The SSIMULACRA 2 image quality metric as WebAssembly for Node.js 22+. No native dependency and no install script.

import { loadScorer, createPool } from "bytecut-ssimulacra2";

const scorer = await loadScorer();
// Packed 8-bit sRGB, 3 bytes per pixel. 100 is identical; higher is better.
const score = scorer.score(
  { data: referenceRgb, width, height },
  { data: encodedRgb, width, height },
);

// Or off the main thread:
const pool = createPool({ size: 4 });
await pool.score(reference, distorted);
await pool.close();

Rough guide: 90+ is visually indistinguishable, 70+ is high quality, 50 is medium.

ssimulacra2.wasm is committed; rebuild it with pnpm build:wasm (needs Rust with the wasm32-unknown-unknown target). The crate is pinned in rust/Cargo.lock. See NOTICE for what is compiled in and under which licences.