<!DOCTYPE html>

<head>
  <meta charset="utf-8" />
  <meta name="viewport" content="width=device-width" />
  <title>Realpha - Restone image's alpha channel</title>
  <script :version="1.0.5" src="/toy/veps.js"></script>
</head>

<style>
  body {
    display: grid;
    grid: 1fr auto 2fr / 1fr 1fr;
    gap: 8px;
    height: calc(100vh - 20px);
  }
  canvas {
    --bg-img: 45deg, #ccc 25%, #0000 25%, #0000 75%, #ccc 75%, #ccc;
    width: 100%;
    height: 100%;
    background: linear-gradient(var(--bg-img)) 0