anchor.diff:                name: 'path/to/image/' + i + '/Chrome'
               };
             });
  -          var matchingCompareSets= compareSets.slice();
  +
  +          // Prepare canvas for images to match against
  +          function getSelectionCanvas(img) {
  +            // Generate our canvas sized down to the selection
  +            // https://github.com/scijs/get-pixels/blob/7c447cd979637b31e47e148f238a1e71611af481/dom-pixels.js#L14-L18
  +            var canvasEl = document.createElement('canvas');
  +            canvasEl.width = targetArea.width;
  +            canvasEl.height = targetArea.height;
  +            var context = canvasEl.getContext('2d');
  +
  +            // Draw a clip for safety (performanc), then our image
  +            // DEV: We haven't tested if this improves performance but assume it should
  +            // https://developer.mozilla.org/en-US/docs/Web/API/CanvasRenderingContext2D/drawImage
  +            // https://developer.mozilla.org/en-US/docs/Web/API/CanvasRenderingContext2D/rect
  +            context.rect(0, 0, targetArea.width, targetArea.height);
  +            context.clip();
  +            context.drawImage(img, -1 * targetArea.left, -1 * targetArea.top);
  +
  +            // Return our generated canvas
  +            return canvasEl;
  +          }
  +          var expectedDiffImg = document.querySelector('#expected-diff-img');
  +          var expectedDiffCanvas = getSelectionCanvas(expectedDiffImg);
  +
  +          document.body.appendChild(expectedDiffCanvas);
  +
  +          // Filter image sets based on matching widths and selection
  +          var matchingCompareSets = compareSets.filter(function matchCompareSet (compareSet) {
  +            return true;
  +          });
   
             // Pass through matching sets to `bulkUpdateSelection`
  +          return;
             bulkUpdateSelection(matchingCompareSets);
           }
   
  
positive.code:           var resultsEl = document.querySelector('#results');
            var resultsDocFrag = document.createDocumentFragment();
  
            // Iterate over our sets
            Array.prototype.forEach.call(compareSets, function forEachCompareSetEl (compareSet) {
              // Localize our references
              var currentImg = compareSet.currentImg;
              var refImg = compareSet.refImg;
  
negative.code:         td
            img(src="gemini-report/images/root/default-large/Chrome~current.png", height=imgHeight)
          td
            img#expected-diff-img(src="gemini-report/images/root/default-large/Chrome~diff.png", height=imgHeight)
          td
            img(src="gemini-report/images/root/default-large/Chrome~ref.png", height=imgHeight)
  
  