Desktop background or desktop wallpaper within the computer hardware is an image set for desktop appearance from the graphical user interface, in particular from the desktop environment.
The terms “wallpaper “desktop background” are related to the image, which is used as a computer screen background that is often the GUI desktop. The term “wallpaper” is used in the Microsoft Windows operation system, while Mac OS calls it “desktop image” (before Mac OS X system was introduced the term “desktop pattern”, which was a small ornament repeated along the whole area of the desktop space).
The images used as desktop wallpaper are usually raster ones, i.e. its dimension is equal to the screen resolution (for instance, 1024×768 or 1280×1024 pixels), which allows to cover the whole screen space. Most screen resolutions are proportional, thus, the image is zoomed and covers the screen real estate with any resolution being undistributed, though the zoom impacts the quality. Some systems such as Mac OS (8.6 Version and higher), KDE (3.4 Version and higher and GNOME support the vector format wallpapers (PICT is applied in Mac OS, SVG in KDE and GNOME). It is considered an advantage, as one file can be used for different screen sizes and can be also expanded for several images without quality loss.
You can sometimes meet wallpapers with a double horizontal size (for instance, 2560×1024) to display them on the multi-screen computers where the picture fills the desktops of two monitors.
Distinctive background under the overlaid windows was first introduced to the test bed office system named Office talk, which was developed by the research center Xerox PARC in 1975 for the computer Alto. Before, it was difficult to distinguish the white background under the overlaid window (for example, within the Small talk system) from the window content. The template color used in Office talk was 25% grey and comprised of 2 pixel high points, that could prevent the flickering of the monitor. Xerox Star computer has borrowed the same template.
The Apple Company used a similar grey background from Lisa and Macintosh computers. However, these computers were not equipped with the string monitors, therefore it was possible to use less recognizable background template, which represented a 2×2 pixel bar, filled with 50% grey. The introduction of digital monitors for personal computers led to the appearance of the template-free single-color background and then to the optional wallpapers.
There is a large variety of desktop wallpapers that makes possible for everyone to choose what he/she likes. These may be photographs, paintings, 3D-graphic and abstraction.
Among the main ones we can number the following: nature, animals, cars, anime, films, video games, celebrities and erotic art.
It’s quite handy if there is a clear area on the wallpapers that makes possible to distinguish the icons.
The desktop wallpapers popularity brought to the introduction of the special programs, which simplify and automate the change of the display images. This being said, the picture can be also chosen in turn or randomly, as well as through the selected time frame.