Computer Graphics

In computer graphics, pictures or graphics objects are presented as o collection of discrete picture elements called pixels. The pixel is the smallest addressable screen element. It is the smallest piece of the display screen which we can control. The control is achieved by setting the intensity and colour of the pixel which compose the screen.

Each pixel on the graphics display does not represent mathematical point. Rather, it represents a region which theoretically can contain a infinite number of points.
The special procedures determine which pixel will the best approximation to the desired picture or graphics object.
The process of determining the appropriate pixels for representing picture or graphics object is known as rasterization, and the process of representing continuous picture or graphics object as a collection of discrete pixels is called scan conversion.
The computer graphics allows rotation, translation, scaling and performing various projections on the picture before displaying it. It also allows to add effects such as hidden surface removal, shading or transparency to the picture before final representation. It provides user the control to modify contents, structure and appearance of pictures or graphics objects using input devices such as a keyboard, mouse, or touch-sensitive panel on the screen. There is a close relationship between the input devices and display devices.
Therefore, graphics devices includes both input devices and display devices.