Overview: Precision and banding

Sample precision, banding and dithering explain how smooth color or luminance changes become discrete signal values.

A smooth gradient has to be represented by a finite set of sample values. When those steps become visible, the picture can show bands. Bit depth describes the available precision, while dithering changes the pattern and visibility of quantization differences.

• Video bit depth
  Video bit depth determines how many distinct coded values are available for each component sample.

• Color banding
  Color banding occurs when a smooth change in picture values is represented by visible plateaus and transitions.

• Dithering
  Video dithering varies quantization decisions across positions or time so rounding error is less likely to form coherent visible bands.