@cfai/video-compare

WebAssembly library for real-time image frame comparison (SSIM/PSNR/MSE)

Installation

npm install @cfai/video-compare

Usage

Node.js

const { VideoComparer } = require('@video-compare/wasm');

async function main() {
  const comparer = await VideoComparer.create();

  const metrics = await comparer.compare({
    left: leftRGBBuffer,   // Uint8Array, width × height × 3 bytes
    right: rightRGBBuffer,
    width: 1920,
    height: 1080,
  });

  console.log(`SSIM: ${metrics.ssim.toFixed(4)}`);
  console.log(`PSNR: ${metrics.psnr.toFixed(2)} dB`);
  console.log(`MSE:  ${metrics.mse.toFixed(2)}`);

  comparer.dispose();
}

main();

Browser

Load the Wasm loader before using the package:

<script src="node_modules/@video-compare/wasm/dist/video-compare.js"></script>
<script type="module">
  import { VideoComparer } from '@video-compare/wasm';

  const comparer = await VideoComparer.create();
  const result = await comparer.compare({ left, right, width, height });
  console.log(result);
</script>

API

VideoComparer.create(config?)

Create a new instance. config is optional:

| Option | Default | Description | |--------|---------|-------------| | maxWidth | 1920 | Max width before downsampling | | maxHeight | 1080 | Max height before downsampling | | blockSize | 16 | Block size for SSIM/MSE computation |

comparer.compare(input)

Compare two frames. Returns { ssim, psnr, mse, width, height, downsampled }.

comparer.dispose()

Free Wasm resources. Instance cannot be reused after this call.

Output Format

| Metric | Range | Interpretation | |--------|-------|----------------| | SSIM | 0–1 | ≥0.95 = identical, <0.80 = very different | | PSNR | dB | ≥40 = excellent, <30 = poor | | MSE | 0–65025 | Lower = more similar |

License

MIT