Output devices

An output device is any piece of computer hardware item which utilizes whatever data and commands from your computer in order to perform a task. This leads to the results of data processing carried out by an information processing system (such as a computer) which converts the electronically generated information into human-readable form.

A display device is an output device that visually conveys text, graphics, and video information. Information shown on a display device is called soft copy because the information exists electronically and is displayed for a temporary period of time. Display devices include CRT monitors, LCD monitors and displays, gas plasma monitors, and televisions.

There are many input and output devices such as multifunction printers and computer-based navigation systems that are used for specialized or unique applications. In computing, input/output refers to the communication between an information processing system (such as a computer), and the outside world. Inputs are the signals or data received by the system, and outputs are the signals or data sent from it.

Some types of output are text, graphics, tactile,audio, and video. Text consists of characters that are used to create words, sentences, and paragraphs. Graphics are digital representations of nontext information such as drawings, charts, photographs, and animation . Tactile output such as raised line drawings may be useful for some individuals who are blind. Audio is music, speech, or any other sound. Video consists of images played back at speeds to provide the appearance of full motion.

A digital image is a numeric representation of an image stored on a computer. They don't have any physical size until they are displayed on a screen or printed on paper. Until that point, they are just a collection of numbers on the computer's hard drive that describe the individual elements of a picture and how they are arranged. Some computers come with built-in graphics capability of . Others need a device, called a graphics card or graphics adapter board, that has to be added. Unless a computer has graphics capability built into the motherboard, that translation takes place on the graphics card. Depending on whether the image resolution is fixed, it may be of vector or raster type. Without qualifications, the term "digital image" usually refers to raster images also called bitmap images. Raster images that are composed of pixels and is suited for photo-realistic images. Vector images which are composed of lines and co-ordinates rather than dots and is more suited to line art, graphs or fonts. To make a 3-D image, the graphics card first creates a wire frame out of straight lines. Then, it rasterizes the image (fills in the remaining pixels). It also adds lighting, texture and color.

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Wikipedia