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                <div id="container">
    <label for="upload-image">1. upload an image</label>
    <input type="file" id="upload-image" name="upload-image" />

  <p id="frame-container">
    <canvas id="frame-canvas"></canvas>

<div id="menu"> 

  <div class="tray">
    <p><a href="index.html">SEURAT.EXTEND()<br /> a <code>var t;</code> demo</a></p>
    <p><small>upload an image, get an art<br /><a href="index.html">learn about  george-pierre seurat</a></small></p>
      <button id="clear">Clear</button>
      <button id="save">Save</button>


                body { font-family: Helvetica; padding: 1em; }

#container p { margin: 0 0 2em; }
label { font-weight: bold; text-transform: uppercase; font-size: 1.5em; display: block; margin: .5em 0; }

#menu { position: absolute; top: 10px; right: 10px; text-align: right;   }
#menu a { text-decoration: none; color: black; font-weight: bold; font-size: 1.2em; }
#menu p { margin-bottom: 10px; }
#menu small { font-family: monospace; }




    var uploadInput = document.getElementById('upload-image');
    var frameContainer = document.getElementById('frame-container');
    var canvas = document.getElementById('frame-canvas');
    var ctx = canvas.getContext('2d');

    var buttonClear = document.getElementById('clear');
    var buttonSave = document.getElementById('save');

    var pixelSize = 15;
    var frameSize;


    var calculateFrameSize = function(dimension) {
      // returns computer-pixel width of frame
      var size = pixelSize * Math.ceil( (dimension * .1) / pixelSize) ;
      return size;
    var drawFrame = function() {

      // go through each 15px pixel and draw 
      for ( var x = 0; x <= canvas.width; x = x + pixelSize ) {
        for ( var y = 0; y <= canvas.height; y = y + pixelSize ) {

          console.log(x, y);
          // only draw if pixel is outside of image
          if ( 
            x < frameSize || 
            y < frameSize ||
            x >= canvas.width - frameSize - 1 ||
            y >= canvas.height - frameSize - 1
          ) {
            ctx.fillStyle = 'lime';
            ctx.fillRect(x, y, pixelSize, pixelSize);


    /** EVENTS **/

    // when uploading an image, embed it onto canvas and show it
    uploadInput.onchange = function(){

      // embed image onto canvas
      var uploadedImage = uploadInput.files[0];
      var reader = new FileReader();
      reader.onload = function(e){
        var img = new Image();
        img.onload =function() {
          // calculate frame width off of smallest dimension
          frameSize = calculateFrameSize(Math.min(img.width, img.height));
 = 'hotpink';
          canvas.width = img.width + 2 * frameSize;
          canvas.height = img.height + 2 * frameSize;

        img.src =;

      // show sketch container = "block";

    // clear canvas when clear button clicked
    buttonClear.onclick = function(){
      ctx.fillStyle = "#ffffff";
      ctx.fillRect(0,0,canvas.width,canvas.height); = 'none';

    // open png in new window when save button clicked
    buttonSave.onclick = function(){'image/png'));