Speckle noise filter
The color of the generated speckles
Density of the speckles, default is 0.1, min, 0.0, max is 1.0
Noisiness of the generated speckles, default is 0.0, min is 0.0, max is 1.0
should the output colors be multiplied by the alpha channel, default is true
noise seed, feed it with time to animate