public GaussianBlur(GraphicsDevice graphicsDevice, int width, int height, SurfaceFormat format, Effect effect)
{
if (graphicsDevice == null) throw new ArgumentNullException("graphicsDevice");
if (width < 1) throw new ArgumentOutOfRangeException("width");
if (height < 1) throw new ArgumentOutOfRangeException("height");
if (height < 1) throw new ArgumentOutOfRangeException("height");
GraphicsDevice = graphicsDevice;
Width = width;
Height = height;
this.effect = effect;
gaussianBlurEffect = new GaussianBlurEffect(effect);
gaussianBlurEffect.Width = width;
gaussianBlurEffect.Height = height;
spriteBatch = new SpriteBatch(graphicsDevice);
backingRenderTarget = new RenderTarget2D(graphicsDevice, width, height, false, format, DepthFormat.None);
}