Editing Bit plane (section)

== Applications ==

=== Media file formats ===
As an example, in [[Pulse-code modulation|PCM]] sound [[code|encoding]] the first bit in the sample denotes the sign of the function, or in other words defines the half of the whole [[amplitude]] values range, and the last bit defines the precise value. Replacement of more significant bits result in more distortion than replacement of less significant bits. In lossy [[Data compression|media compression]] that uses bit-planes it gives more freedom to encode less significant bit-planes and it is more critical to preserve the more significant ones.<ref>{{cite journal
  | last =Cho
  | first =Chuan-Yu
  | authorlink =
  | author2 =Chen, Hong-Sheng | author3 = Wang, Jia-Shung
  | title =Smooth Quality Streaming With Bit-Plane Labelling
  | journal =Visual Communications and Image Processing
  | volume =5690
  | issue =
  | pages =2184–2195
  | publisher =The International Society for Optical Engineering
  | date =July 2006
  | bibcode =2005SPIE.5960.2184C
  | doi =10.1117/12.633501
  | id =
  
  | type =abstract  | series =Visual Communications and Image Processing 2005
  | s2cid =62549171
 }}</ref>

As illustrated in the image above, the early bitplanes, particularly the first, may have constant runs of bits, and thus can be efficiently encoded by [[run-length encoding]]. This is done (in the transform domain) in the [[Progressive Graphics File]] image format, for instance.

=== Bitmap displays ===
Some computers displayed graphics in [[Planar (computer graphics)|bit-plane format]], most notably PC with [[Enhanced Graphics Adapter|EGA]] graphics card, the [[Amiga]] and [[Atari ST]], contrasting with the more common [[Packed pixel|packed format]]. This allowed certain classes of image manipulation to be performed using bitwise operations (especially by a [[blitter]] chip), and parallax scrolling effects.

=== Video motion estimation ===

Some [[motion estimation]] algorithms can be performed using bit planes (e.g. after the application of a filter to turn salient edge features into binary values).<ref>{{cite CiteSeerX|title=bitlane motion estimation|citeseerx=10.1.1.16.1755}}</ref> This can sometimes provide a good enough approximation for correlation operations with minimal computational cost. This relies on an observation that the spatial information is more significant than the actual values. Convolutions may be reduced to [[bit shift]] and [[popcount]] operations, or performed in dedicated hardware.

=== Neural networks ===

Bitplane formats may be used for passing images to [[Spiking neural networks]], or low precision approximations to [[Artificial neural network|neural networks]]/[[convolutional neural networks]].<ref>{{cite arXiv
  | title=xnor net
  | eprint=1603.05279
  | last1=Rastegari|first1=Mohammad
  | last2=Ordonez|first2=Vicente
  | last3=Redmon|first3=Joseph
  | last4=Farhadi|first4=Ali
  | class=cs.CV
  | year=2016  }}</ref>