Aurora, the default wallpaper for Windows
Vista.
A screenshot of Ubuntu 6.06
LTS, showing Dawn of Ubuntu wallpaper
The terms wallpaper and desktop picture refer to an image used
as a background on a computer screen, usually for the desktop of a graphical user
interface. 'Wallpaper' is the term used in Microsoft Windows,
while the Mac
OS calls it a 'desktop picture' (prior to Mac OS X, the term desktop
pattern was used to refer to a small pattern that was repeated to fill the
screen).
Formats
Images used as computer wallpaper are usually raster graphics with the
same size as the display resolution
(for example 1024×768 pixels, or 1280×1024 pixels) in order to fill the whole
background. Many screen resolutions are proportional,
so an image scaled to fit in a different-sized screen will often be the correct
shape, albeit that scaling may impact quality. PNG and JPEG format are common.
Users with widescreen (16:9 or 16:10)
monitors have different aspect ratio
requirements for wallpaper, although images designed for standard (4:3) monitors can often be scaled or cropped to the
correct shape without loss of quality.
Wallpapers are sometimes available in double-width versions (e.g. 2560×1024)
for displaying on multi-monitor computers, where the image appears to fill two
monitors.
Some display systems allow unconventionally-proportioned images (1:1, 2:1, or
even 1:3) to be scaled without change of proportion, to fit the screen, whether
it be 16:9 or 4:3. The image would be sized just large enough that one pair of
edges touch the edges of the screen, but not all four, as this would unduly
distort the image.
Most display systems are capable of specifying a single-colour to use as the
background in place of a wallpaper, and some (such as KDE or GNOME) allow colour-gradients to
be specified. Microsoft Windows 3.x
and 9x systems allow using editable repeating two-color 8×8 tiles
for background.
Some desktop systems, such as Mac OS (version 8.6 or later),
KDE (version 3.4 or later), and GNOME, support vector wallpapers (PICT in Mac and SVG in KDE and
GNOME). This has the advantage that a single file may be used for screens of any
size, or stretched across several screens, without loss of quality.
History
Original computer wallpaper pattern, as used in Xerox's
Officetalk and Star; actual
size.
The first use of a distinguishable background in conjunction with overlapping
windows was in an experimental office system, Officetalk, developed in 1975 at Xerox
PARC on the Alto. Prior to that, the
white backgrounds to overlapping windows (for example, in Smalltalk) could be difficult
to distinguish from window interiors. The pattern used in Officetalk produced a
25% gray, using dots two pixels high to avoid flicker on the Alto's interlaced
screen. The same pattern was adopted for the Xerox Star.
Apple used a similar gray
background for their Lisa and Macintosh. However, since
these machines had non-interlaced screens it was possible to use a less
noticeable background pattern, formed from a simple 2x2 repeating pattern that
gave a 50 percent gray. The introduction of color monitors for personal
computers led to non-patterned, single-color backgrounds and then to arbitrary
'wallpapers'.
Styles
Wallpaper styles are as varied as people themselves, using photographs,
drawings, 3D renders or abstract pattern with complex gradients. It can be useful to
have plain areas so that icons can be clearly
seen atop the wallpaper.
Typical categories can include cars, models and celebrities, scenery, abstract
art, movies, pets, family, symmetry, and personal
photos.
In business use, corporate logos or plain backgrounds are
often specified by the companies' guidelines.
When using rack mounted computers
through a KVM switch, it can often be
useful to create a wallpaper with the computer's name on it, to easily identify
which computer you're connected to.
Dynamic backgrounds
Some operating environments (e.g. KDE and Mac OS X) allow a number of
different wallpapers to be used, and "rotated" to display a different wallpaper
at different times, to display a random image from a directory. If
the facility is not available in the OS' wallpaper settings, it may be possible
to get an external program which can change the wallpaper at certain times.
Microsoft Windows 98 and higher allow webpages to be set as frames on the
desktop which may be dynamic pages.
Programs such as Xplanet and EarthDesk use Internet
connections and graphics calculations to change the wallpaper with real data,
such as a shadowed view of the earth, the latest cloud or weather map, or
various events. Some media players can redirect video playback to desktop,
allowing any video to be used as a wallpaper. Other tools (for example WireChanger) can
add interactive widgets to a wallpaper, such as
calendar, notes, RSS feed, or generate
a wallpaper image using various algorithms.
Macromedia/Adobe Flash animated movies and games can be set a dynamic
interactive background as well. Point your desktop background settings to an
html file with embedded flash movie instead of an image.
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