dither is an intentionally introduced fluctuation that makes a quantizer's output vary between codes, reducing signal-correlated quantization artifacts. A suitable distribution can make the averaged code carry information about a constant voltage smaller than one conversion step. The improvement requires filtering or averaging; extra noise does not improve an individual conversion or repair arbitrary calibration errors.
Let a constant input lie a fraction of the way between two consecutive quantizer levels separated by . With independent uniform additive dither spanning one step and nearest-level rounding, the two output codes occur with probabilities and . Their mean equals the input and their sample-average variance is the displayed expression. This simple model shows both the sub-step information and the remaining noise cost.
Articles by others on the same topic
Dither is a technique used in digital signal processing and digital image processing to reduce the appearance of noise or to create the illusion of color depth in images with limited color palettes. Essentially, dither introduces small, random variations in data, which can help to smooth out transitions and create a more visually appealing or accurate representation. In the context of audio, dithering involves adding low-level noise to the audio signal before reducing its bit depth (e.g.