Noise


[Abstract]:

A thorough investigation and presentation of what noise has to offer visually upon digital imagery; also introducing the different and features of noise. Noise is an interesting and important element for digital artists and photo enhancers. This research will demonstate how noise can be used, what the noise controls are, then how to apply, adjust, and simulate noise.

[Definition]:

Noise is unwanted electrical or electromagnetic energy that degrades the quality of signals and data. Noise occurs in digital and analog systems, and can affect files and communications of all types, including text, programs, images, audio, and telemetry. Noise is quite simple, an effect where every pixel gets a random value added to it. This may sound simple, but it can be the first step towards just about any surface that has that "natural chaos" look to it. There is complicated math behind noise, but you don't really need to understand the math to use the techniques.

[Features]:

[Controls]:

[Examples | Illustrations]:


Above, we see Uniform noise. Values here are purely random and unbiased, so that any value is (in theory) just as likely as any other value. This was done with a value of 56 in the Amount slider, so all values fall randomly between (128-56)/256 and (128+56)/256.


This is Gaussian noise. Here, the randomness falls into more of a curve, where midtones are most likely, and darks and lights are rare. You'll notice that values here are found beyond the +/-56 border that the Uniform noise fell into, even though this was also made with an Amount of 56. This value, in this case, is acting more as a midpoint, and the curve continues to approach 0% probability as it reaches positive and negative infinity, in theory. In reality, it bumps into solid white and solid black and bunches up there. You can see the spikes at the very edges of the graph.

[Links]:

http://www.graphic-design.com/Photoshop/noise/index.html