Computer Graphics: Introduction

Computer Graphics

Introduction:

Computer Graphics is a field related to the generation of graphics using computers. It includes the creation, storage, and manipulation of images of objects. These objects come from diverse fields such as physical, mathematical, engineering, architectural, abstract structures and natural phenomenon. Computer graphics today is largely interactive, that is , the user controls the contents, structure, and appearance of images of the objects by using input devices, such as keyboard, mouse, or touch-sensitive panel on the screen.

            Until the early 1980's computer graphics was a small, specialized field, largely because the hardware was expensive and graphics-based application programs that were easy to use and cost-effective were few. Then personal computers with built-in raster graphics displays-such as the Xerox Star, Apple Macintosh and the IBM PC- popularized the use of bitmap graphics for user-computer interaction. A bitmap is a ones and zeros representation of the rectangular array points on the screen. Each point is called a pixel, short for "Picture Elements" . Once bitmap graphics became affordable, and explosion of easy-to-use and inexpensive graphics-based applications soon followed. Graphics-based user interfaces allowed millions of new users to control simple, low-cost application programs, such as word-processors, spreadsheets, and drawing programs.

            The concepts of a "desktop" now became a popular for organizing screen space. By means of a window manager, the user could create, position and resize rectangular screen areas called windows. This allowed user to switch among multiple activities just by pointing and clicking at the desired window, typically with a mouse. Besides windows, icons which represent data files, application program, file cabinets, mailboxes, printers, recycle bin, and so on, made the user-computer interaction more effective. By pointing and clicking the icons, users could activate the corresponding programs or objects, which replaced much of the typing of the commands used in earlier operating systems and computer applications.

            Today, almost all interactive application programs, even those for manipulating text(e.g.. word processor) or numerical data (e.g. spreadsheet programs), use graphics extensively in the user interface and for visualizing and manipulating the application-specific objects.

            Even people who do not use computers encounter computer graphics in TV commercials and as cinematic special effects. Thus computer graphics is and integral part of all computer user interfaces, and is indispensable for visualizing 2D, 3D objects in all most all areas such as education, science, engineering, medicine, commerce, the military, advertising, and entertainment. The theme is that learning how to program and use computers now includes learning how to use simple 2D graphics.