Editing Alpha compositing (section)

==Other transparency methods==
Although used for similar purposes, [[Palette (computing)#Transparent color in palettes|transparent color]]s and [[Mask (computing)#Image masks|image mask]]s do not permit the smooth blending of the superimposed image pixels with those of the background (only whole image pixels or whole background pixels allowed).

A similar effect can be achieved with a 1-bit alpha channel, as found in the 16-bit RGBA [[high color]] mode of the [[Truevision TGA]] [[image file format]] and related [[TARGA]] and AT-Vista/NU-Vista display adapters' high color graphic mode. This mode devotes 5 bits for every primary RGB color ([[List of monochrome and RGB color formats#15-bit RGB|15-bit RGB]]) plus a remaining bit as the "alpha channel".

[[Dither]]ing can be used to simulate partial occlusion where only 1-bit alpha is available.

For some applications, a single alpha channel is not sufficient: a [[Stained glass|stained-glass window]], for instance, requires a separate transparency channel for each RGB channel to model the red, green and blue transparency separately. More alpha channels can be added for accurate spectral color filtration applications.

Some [[order-independent transparency]] methods replace the '''over''' operator with a commutative approximation.<ref>{{cite journal |last1=McGuire |first1=Morgan |last2=Bavoil |first2=Louis |date=2013 |title=Weighted Blended Order-Independent Transparency |journal=Journal of Computer Graphics Techniques|volume=2 |issue=2 |pages=122–141 |url=https://www.jcgt.org/published/0002/02/09/ }}</ref>