In the context of video, signal distortion—known more colloquially as “noise”—can take the form of a random pattern of pixels that do not represent visual features in the scene being captured, or coherent noise produced by a particular device’s characteristics. A certain degree of noise is inevitable in any electronic device that transmits or receives a signal, and in video cameras, noise is a by-product of image capture.

Perhaps counterintuitively, higher-resolution cameras are more susceptible to noise. The reason is that the elements on the optical sensor are smaller and thus able to collect less light, narrowing tolerances and making errors more likely. Moreover, to compensate for the lesser amount of light collected by individual sensor elements, greater signal amplification is often applied, which itself introduces noise. More generally, for any given camera, low-light conditions will result in higher noise levels.

What's inside?

• Types of noise reduction approaches
• The need for an integrated approach
• Benefits of noise reduction