Blue Noise

What Does Blue Noise Mean?

Blue noise increases in volume with increasing frequency, but at a lower rate than a similar kind of noise called violet noise.


Blue noise is also known as azure noise.

Techopedia Explains Blue Noise

Blue noise is one of many terms for different kinds of noise that operate differently across the noise frequency spectrum. Blue noise is characterized as a noise with a less intense frequency increase than purple noise. It can also be contrasted to pink noise, where intensity decreases by a similar margin over a finite frequency range. That relative increase and decrease is 3 decibels per octave.

In terms of its use, blue noise is sometimes used for randomization or pattern projection, such as in digital images utilizing or transitioning from grayscale. For example, a strategy called dithering is used in audio and video processes to help to project different changes to images. Blue noise can be useful in dithering because of its logarithmic function.


Related Terms

Margaret Rouse
Technology Expert

Margaret is an award-winning technical writer and teacher known for her ability to explain complex technical subjects to a non-technical business audience. Over the past twenty years, her IT definitions have been published by Que in an encyclopedia of technology terms and cited in articles by the New York Times, Time Magazine, USA Today, ZDNet, PC Magazine, and Discovery Magazine. She joined Techopedia in 2011. Margaret's idea of a fun day is helping IT and business professionals learn to speak each other’s highly specialized languages.