CSS Critic reporter to find offending pixels

gistfile1.txt

 csscritic.addReporter({
     reportComparison: function (comparison) {
         if (imagediff.equal(comparison.pageImage, comparison.referenceImage)) {
             return;
         }
         var d = imagediff.diff(comparison.pageImage, comparison.referenceImage, {align: 'top'}).data;
         var pixelDiff = [], i;
         for (i=0; i < d.length; i += 4) {
             if (d[i] !== 0 || d[i+1] !== 0 || d[i+2] !== 0 || d[i+3] !== 255) {
                 pixelDiff.push([d[i], d[i+1], d[i+2], d[i+3]]);
             }
         }
         console.log(comparison.testCase.url, pixelDiff.length, pixelDiff);
     }
 });