Editing Pixel (section)

===Subpixels===
[[Image:Pixel geometry 01 Pengo.jpg|thumb|upright=0.9|Geometry of color elements of various CRT and LCD displays]]

Many display and image-acquisition systems are not capable of displaying or sensing the different [[Channel (digital image)|color channels]] at the same site. Therefore, the pixel grid is divided into single-color regions that contribute to the displayed or sensed color when viewed at a distance. In some displays, such as LCD, LED, and plasma displays, these single-color regions are separately addressable elements, which have come to be known as '''subpixels''', mostly [[RGB]] colors.<ref>{{cite dictionary|url=http://dictionary.reference.com/browse/pixel|title=''Subpixel'' in Science|dictionary=[[dictionary.com]]|access-date=4 July 2015|url-status=live|archive-url=https://web.archive.org/web/20150705170454/http://dictionary.reference.com/browse/pixel|archive-date=5 July 2015}}</ref> For example, [[LCD]]s typically divide each pixel vertically into three subpixels. When the square pixel is divided into three subpixels, each subpixel is necessarily rectangular. In display industry terminology, subpixels are often referred to as ''pixels'', as they are the basic addressable elements in a viewpoint of hardware, and hence ''pixel circuits'' rather than ''subpixel circuits'' is used.
[[File:Samsung TV subpixels..jpg|thumb|[[Samsung]] UA40M5860AKCHD TV subpixels]]
Most digital camera [[image sensor]]s use single-color sensor regions, for example using the [[Bayer filter]] pattern, and in the camera industry these are known as ''pixels'' just like in the display industry, not ''subpixels''.

For systems with subpixels, two different approaches can be taken:
* The subpixels can be ignored, with full-color pixels being treated as the smallest addressable imaging element; or
* The subpixels can be included in rendering calculations, which requires more analysis and processing time, but can produce apparently superior images in some cases.

This latter approach, referred to as [[subpixel rendering]], uses knowledge of [[pixel geometry]] to manipulate the three colored subpixels separately, producing an increase in the apparent resolution of color displays. While [[cathode-ray tube|CRT]] displays use red-green-blue-masked phosphor areas, dictated by a mesh grid called the shadow mask, it would require a difficult calibration step to be aligned with the displayed pixel raster, and so CRTs do not use subpixel rendering.

The concept of subpixels is related to [[Sample (graphics)|samples]].