@blazediff/core-native

type NativeDiffResult =
  | { kind: "compared"; count: number; percentage: number; identical: boolean;
      window?: { x: number; y: number; count: number } }
  | { kind: "dimension-mismatch"; a: Size; b: Size }
  | { kind: "io-error"; path?: string; message: string };

import { diff } from '@blazediff/core-native';
 
const result = await diff('expected.png', 'actual.png', {
  output: 'diff.png',
  threshold: 0.1,
});
 
if (result.kind === 'compared') {
  if (result.identical) console.log('Images are identical!');
  else console.log(`${result.count} pixels differ (${result.percentage.toFixed(2)}%)`);
} else if (result.kind === 'dimension-mismatch') {
  console.log('Images have different dimensions');
} else {
  console.log(`Could not read ${result.path}: ${result.message}`);
}

import { readFile } from "node:fs/promises";
import { diff } from "@blazediff/core-native";
 
const [expected, actual] = await Promise.all([
  readFile("expected.png"),
  readFile("actual.png"),
]);
 
// Reuse these same Buffer objects across comparisons without a JS-to-Rust copy.
const result = await diff(expected, actual, { output: "diff.png" });

# Compare two PNG images and write the diff
npx blazediff expected.png actual.png -o diff.png
 
# Compare two JPEG images
npx blazediff expected.jpg actual.jpg -o diff.jpg
 
# Mixed formats (PNG input, QOI output - recommended for smallest diff files)
npx blazediff expected.png actual.png -o diff.qoi
 
# Stricter threshold, anti-aliased pixels counted
npx blazediff expected.png actual.png -o diff.png --threshold 0.05 --no-antialiasing
 
# pixelmatch 8 metric and the busiest 16×16 window, as JSON
npx blazediff expected.png actual.png --metric oklab --window 16 --json
 
# With higher PNG compression (smaller output file, slower)
npx blazediff expected.png actual.png -o diff.png -c 6

Usage: blazediff [OPTIONS] <A> <B>
 
Options:
  -o, --output <OUTPUT>            Write the diff image here (only when the images differ)
  -t, --threshold <THRESHOLD>      Color difference threshold (0.0-1.0) [default: 0.1]
      --antialiasing               Detect anti-aliased pixels and leave them out of the count (default)
      --no-antialiasing            Count anti-aliased pixels as differences
      --metric <METRIC>            Color difference metric: yiq or oklab (pixelmatch 8) [default: yiq]
      --mask <MASK>                Image the size of the inputs; its non-black pixels are skipped
      --window <WINDOW>            Also report the N×N window with the most diff pixels
  -a, --alpha <ALPHA>              Opacity of the faded background (0.0-1.0) [default: 0.1]
      --diff-color <R,G,B>         RGB color for differing pixels
      --diff-color-alt <R,G,B>     RGB color for pixels that get darker in the second image
      --aa-color <R,G,B>           RGB color for anti-aliased pixels
      --background <BACKGROUND>    faded or transparent [default: faded]
  -c, --compression <COMPRESSION>  PNG compression level (0-9) [default: 0]
  -q, --quality <QUALITY>          JPEG quality (1-100) [default: 90]
      --json                       Print the result as JSON
  -h, --help                       Print help
  -V, --version                    Print version

import { interpret } from '@blazediff/interpret-native';
 
const result = await interpret('expected.png', 'actual.png');
console.log(result.summary);
// "Moderate visual change detected (1.87% of image, 4 regions).
//  Content changed: 1 region (bottom).
//  Content added: 2 regions (right, bottom-left)."