code: function isType2or4(frameData) {
      var zeroPositions = [0, 1, 8, 9, 24, 25, 48, 49, 80, 81, 120, 121, 168, 169, 224, 225];
      for (var i = 0; i < zeroPositions.length; i++) {
          if (frameData[zeroPositions[i]] !== 0) {
              return false;
          }
      }
  
      return true;
  }
docs: Returns true if the image is a less-than (<) shape.