HTML5VideoImageProcessing/sobel.html at master · DaisukeHirata/HTML5VideoImageProcessing · GitHub

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<!doctype html>
<html>
  <head>
    <meta charset="utf-8">
    <title>Video Frames</title>
    <link rel="stylesheet" href="style.css">
    <style>
      #movieclip {
        display: none;
      }
    </style>
  </head>
  <body>
    <header>Avoid cross domain security error. $ http-server -p 8000 </header>
    <canvas id="canvas"></canvas>

    <video id="movieclip" autoplay>
      <source src="./assets/movieclip.mp4" type="video/mp4"/>
      <source src="./assets/movieclip.webm" type="video/webm"/>
      <source src="./assets/movieclip.ogv" type="video/ogg"/>
    </video>

    <script src="utils.js"></script>
    <script src="Stats.js"></script>
    <script src="Filters.js"></script>
    <script src="camera.js"></script>
    <script>
    window.onload = function () {

      var canvas = document.getElementById('canvas'),
          context = canvas.getContext('2d'),
          video = document.getElementById('movieclip'),
          stats = Stat.initStats();

      Camera.createPlayButton(video);

      (function drawFrame () {

        stats.begin();

        window.requestAnimationFrame(drawFrame, canvas);
        canvas.width = video.videoWidth;
        canvas.height = video.videoHeight;
        context.drawImage(video, 0, 0);

        var imageData = context.getImageData(0, 0, canvas.width, canvas.height);

        var grayscale = Filters.grayscale(imageData);

        var vertical = Filters.convoluteFloat32(grayscale,
                                                [ -1, 0, 1,
                                                  -2, 0, 2,
                                                  -1, 0, 1 ]);

        var horizontal = Filters.convoluteFloat32(grayscale,
                                                [ -1, -2, -1,
                                                   0,  0,  0,
                                                   1,  2,  1 ]);

        var final_image = Filters.createImageData(vertical.width, vertical.height);
        for (var i=0; i<final_image.data.length; i+=4) {
          // make the vertical gradient red
          var v = Math.abs(vertical.data[i]);
          final_image.data[i] = v;
          // make the horizontal gradient green
          var h = Math.abs(horizontal.data[i]);
          final_image.data[i+1] = h;
          // and mix in some blue for aesthetics
          final_image.data[i+2] = (v+h)/4;
          final_image.data[i+3] = 255; // opaque alpha
        }

        context.putImageData(imageData, 0, 0);
        context.putImageData(final_image, 0, 0);

        stats.end();

      }());
    };
    </script>
  </body>
</html>