code: function ConvolutionFilter(matrix, width, height)
  {
      core.AbstractFilter.call(this,
          // vertex shader
          null,
          // fragment shader
          fs.readFileSync(__dirname + '/convolution.frag', 'utf8'),
          // custom uniforms
          {
              matrix:     { type: '1fv', value: new Float32Array(matrix) },
              texelSize:  { type: '2v', value: { x: 1 / width, y: 1 / height } }
          }
      );
  }
docs: The ConvolutionFilter class applies a matrix convolution filter effect.
  A convolution combines pixels in the input image with neighboring pixels to produce a new image.
  A wide variety of image effects can be achieved through convolutions, including blurring, edge
  detection, sharpening, embossing, and beveling. The matrix should be specified as a 9 point Array.
  See http://docs.gimp.org/en/plug-in-convmatrix.html for more info.
  
  @class
  @extends AbstractFilter
  @memberof PIXI.filters
  @param matrix {number[]} An array of values used for matrix transformation. Specified as a 9 point Array.
  @param width {number} Width of the object you are transforming
  @param height {number} Height of the object you are transforming