Editing Spatial anti-aliasing (section)

==Examples==
In computer graphics, anti-aliasing improves the appearance of "jagged" polygon edges, or "[[jaggies]]", so they are smoothed out on the screen. However, it incurs a performance cost for the [[Graphics Card|graphics card]] and uses more [[video memory]]. The level of anti-aliasing determines how smooth [[Polygon edge|polygon edges]] are (and how much video memory it consumes).{{Multiple image
| align             = 
| direction         = 
| total_width       = 900
| image1            = Aliased.png
| alt1              = 
| caption1          = Visual distortion when anti-aliasing is not used
| image2            = Antialiased.png
| caption2          = Anti-aliased
| caption3          = Anti-aliased via [[Lanczos resampling]]
| image3            = Antialiased lanczos.png
| image4            = Antialiased-zoom.png
| caption4          = Magnified portion of image lacking anti-aliasing (left) and anti-aliased (right)
}}

Near the top of an image with a receding checker-board pattern, the image is difficult to recognise and often not considered aesthetically pleasing. In contrast, when anti-aliased the checker-board near the top blends into grey, which is usually the desired effect when the [[Image resolution|resolution]] is insufficient to show the detail. Even near the bottom of the image, the edges appear much smoother in the anti-aliased image. Multiple methods exist, including the [[sinc filter]], which is considered a better anti-aliasing algorithm.<ref name = refA>{{cite journal |doi=10.1145/965105.807509 |author=Leler, William J. |title=Human vision, anti-aliasing, and the cheap 4000 line display |journal=ACM SIGGRAPH Computer Graphics |volume=14 |issue=3 |pages=308–313 |date=July 1980 }}
</ref> When magnified, it can be seen how anti-aliasing interpolates the brightness of the pixels at the boundaries to produce grey [[pixel]]s since the space is occupied by both black and white tiles. These help make the sinc filter antialiased image appear much smoother than the original.
[[File:Anti-aliased-diamonds.png|alt=|left|thumb|upright=1.3|Left: an aliased version of a simple shape. Right: an anti-aliased version of the same shape.]]
In a simple diamond image, anti-aliasing blends the boundary pixels; this reduces the aesthetically jarring effect of the sharp, step-like boundaries that appear in the aliased graphic.

Anti-aliasing is often applied in rendering text on a computer screen, to suggest smooth contours that better emulate the appearance of text produced by conventional ink-and-paper printing. Particularly with [[Computer font|fonts]] displayed on typical LCD screens, it is common to use [[subpixel rendering]] techniques like [[ClearType]]. Sub-pixel rendering requires special colour-balanced anti-aliasing filters to turn what would be severe colour distortion into barely-noticeable colour fringes. Equivalent results can be had by making individual sub-pixels addressable as if they were full pixels, and supplying a hardware-based anti-aliasing filter as is done in the [[OLPC XO-1]] laptop's display controller. [[Pixel geometry]] affects all of this, whether the anti-aliasing and sub-pixel addressing are done in software or hardware.