Wallpaper styles are as changing and various as people themselves, using photographs, drawings, 3D renders or abstract pattern with complex gradients. It can be helpful to have plain areas so that icons can be clearly seen atop the wallpaper.
Most common categories can include cars, models and celebrities, scenery, pets, movies, family, and personal photos.
When using rack mounted computers through a switch, it can often be useful to make a wallpaper with the computer's name on it, to easily identify which computer the user is connecting to.
System themes are often distributed with a background image that fits the style of the theme.
Certain operating systems allow a number of various 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's wallpaper settings, it may be possible to get an external program which can change the wallpaper at certain times. Microsoft Windows versions 98 through XP allow webpages to be set as frames on the desktop which may be dynamic pages. Adobe Flash can also be used to create dynamic (and interactive) wallpapers as well by setting the wallpaper to an HTML file with an embedded Flash image.
Windows Vista Ultimate also has the ability to use a video as a wallpaper. Users can choose to use their own home videos which loop continuously, or use one already installed.
Certain media players (mplayer) provide the option to output video to the background of X11, making them suitable as an engine for animated backgrounds from a wide range of video formats.
Programs like 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.
вівторок, 28 жовтня 2008 р.
The first and foremost screensavers...
The first screensavers for free were allegedly written for the original IBM PC by John Socha, best known for creating the Norton Commander; he also coined the term screen saver. The screensaver, named scrnsave, was published in December 1983 issue of the Softalk magazine. It simply blanked the screen after three minutes of inactivity (an interval which could be changed only by recompiling the program).
The Atari 400 and 800's screens would also go through random screensaver-like color changes if they were left inactive for too long. The user had no control over this. These computers, released in 1979, are technically earlier "screen savers." And prior to these computers, the 1977 Atari VCS/2600 gaming console included color cycling in games like Combat or Breakout, in order to prevent burn-in of game images to 1970's-era televisions. These are examples of screensavers in ROM or the firmware of a computer.
Today with the help of modern graphics technologies there is a wide variety of different screensavers. Because of 3D computer graphics, which provide realistic environments, 3D screensavers are available.
Monitors that are running free screensavers consume the same amount of power as when running normally, which can be anywhere from a few watts for small LCD monitors to several hundred for large plasma displays. Most modern computers can be set to switch the monitor into a lower power mode. A power saving mode for monitors is usually part of the power management options supported in most modern operating systems, though it must also be supported by the computer hardware and monitor itself.
Additionally, using screensavers free with a flat panel or LCD screen instead of powering down the screen can actually reduce the lifetime of the display, since the fluorescent backlight remains lit and ages faster than it would if the screen was turned off completely. As fluorescent tubes age they grow progressively dimmer. A typical LCD screen loses about 50% of its brightness during a normal product lifetime. (In most cases, the tube is an integral part of the LCD and the entire assembly needs to be changed out)
Thus the term "screen saver" is somewhat a misnomer—the best way to save the screen (and also save electricity) would simply be to have the computer turn off the monitor.
Notice also that screensavers as well as free screensavers may utilize a significant amount of CPU time. On a busy server this might be a problem.
An early screensaver for the Macintosh platform, and later PC/Windows, After Dark, prominently featured whimsical designs such as flying toasters. Perhaps in response to the workplace environment in which they are often viewed, many great screensavers continue this legacy of whimsy by populating the idle monitor with animals or fish, games, and visual expressions of mathematics equations such as fractals.
The screensaver is also an outlet for the work of creative computer programmers. The Unix-based screensaver XScreenSaver collects the display effects of other Unix screensavers, which are termed "display hacks" in the jargon file tradition of US computer science academics. It also collects forms of computer graphics effects called demo effects, originally included in demos created by the demo scene.
The Atari 400 and 800's screens would also go through random screensaver-like color changes if they were left inactive for too long. The user had no control over this. These computers, released in 1979, are technically earlier "screen savers." And prior to these computers, the 1977 Atari VCS/2600 gaming console included color cycling in games like Combat or Breakout, in order to prevent burn-in of game images to 1970's-era televisions. These are examples of screensavers in ROM or the firmware of a computer.
Today with the help of modern graphics technologies there is a wide variety of different screensavers. Because of 3D computer graphics, which provide realistic environments, 3D screensavers are available.
Monitors that are running free screensavers consume the same amount of power as when running normally, which can be anywhere from a few watts for small LCD monitors to several hundred for large plasma displays. Most modern computers can be set to switch the monitor into a lower power mode. A power saving mode for monitors is usually part of the power management options supported in most modern operating systems, though it must also be supported by the computer hardware and monitor itself.
Additionally, using screensavers free with a flat panel or LCD screen instead of powering down the screen can actually reduce the lifetime of the display, since the fluorescent backlight remains lit and ages faster than it would if the screen was turned off completely. As fluorescent tubes age they grow progressively dimmer. A typical LCD screen loses about 50% of its brightness during a normal product lifetime. (In most cases, the tube is an integral part of the LCD and the entire assembly needs to be changed out)
Thus the term "screen saver" is somewhat a misnomer—the best way to save the screen (and also save electricity) would simply be to have the computer turn off the monitor.
Notice also that screensavers as well as free screensavers may utilize a significant amount of CPU time. On a busy server this might be a problem.
An early screensaver for the Macintosh platform, and later PC/Windows, After Dark, prominently featured whimsical designs such as flying toasters. Perhaps in response to the workplace environment in which they are often viewed, many great screensavers continue this legacy of whimsy by populating the idle monitor with animals or fish, games, and visual expressions of mathematics equations such as fractals.
The screensaver is also an outlet for the work of creative computer programmers. The Unix-based screensaver XScreenSaver collects the display effects of other Unix screensavers, which are termed "display hacks" in the jargon file tradition of US computer science academics. It also collects forms of computer graphics effects called demo effects, originally included in demos created by the demo scene.
Don't confuse screensavers with...
Free Screensaver software can also be used as a rudimentary security measure. Many screensavers can be configured to ask users for a password before permitting the user to resume work. However, a user might be able to circumvent the password by restarting the computer if the computer's owner has set their account to automatically log in.
Screensavers are not to be confused with power management features. In fact, screensavers can actually waste power, because they can prevent the computer from entering the lower power (or sleep) state, and they often cause the CPU and GPU to perform more calculations, and keep the hard disk running for longer than if the computer were idle.
Screensaver programs were designed to help avoid effects by automatically changing the images on the screen during periods of user inactivity.
Older machines designed without burn-in problems taken into consideration often display evidence of screen damage, with images or text such as "Please insert your card" (in the case of ATMs) visible even when the display changes while the machine is in use. Blanking the screen is out of the question as the machine would appear to be out of service. In these applications, burn-in is prevented by shifting the position of the display contents every few seconds, or by having a number of different images that are changed regularly.
Modern CRTs are much less susceptible to burn-in than older models due to improvements in phosphor coatings, and because modern computer images are generally lower contrast than the stark green- or white-on-black text and graphics of earlier machines. LCD computer monitors, including the display panels used in laptop computers, are not susceptible to burn-in because the image is not directly produced by phosphors. For these reasons, screensavers today are primarily decorative or for entertainment, and usually feature moving images or patterns and sometimes sound effects.
One increasingly popular application is for free screensavers to activate a useful background task, such as a virus scan or a distributed computing application. This is convenient because these things only use resources when the computer would be otherwise idle, and thus are very efficient.
Screensavers are not to be confused with power management features. In fact, screensavers can actually waste power, because they can prevent the computer from entering the lower power (or sleep) state, and they often cause the CPU and GPU to perform more calculations, and keep the hard disk running for longer than if the computer were idle.
Screensaver programs were designed to help avoid effects by automatically changing the images on the screen during periods of user inactivity.
Older machines designed without burn-in problems taken into consideration often display evidence of screen damage, with images or text such as "Please insert your card" (in the case of ATMs) visible even when the display changes while the machine is in use. Blanking the screen is out of the question as the machine would appear to be out of service. In these applications, burn-in is prevented by shifting the position of the display contents every few seconds, or by having a number of different images that are changed regularly.
Modern CRTs are much less susceptible to burn-in than older models due to improvements in phosphor coatings, and because modern computer images are generally lower contrast than the stark green- or white-on-black text and graphics of earlier machines. LCD computer monitors, including the display panels used in laptop computers, are not susceptible to burn-in because the image is not directly produced by phosphors. For these reasons, screensavers today are primarily decorative or for entertainment, and usually feature moving images or patterns and sometimes sound effects.
One increasingly popular application is for free screensavers to activate a useful background task, such as a virus scan or a distributed computing application. This is convenient because these things only use resources when the computer would be otherwise idle, and thus are very efficient.
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