Definition-of-Computer-Graphics

Graphics (from Greek γραφικός graphikos,"belonging to drawing") are visual images or designs on some surface, such as a wall, canvas, screen, paper, or stone to inform, illustrate, or entertain. In contemporary usage it includes: a pictorial representation of data, as in computer-aided design and manufacture, in typesetting and the graphic arts, and in educational and recreational software.
Example:
1. Photographs
2. Drawings
3. Line art
4. Graphs
5. Diagrams
6. Maps
7. Engineering drawings
Introduction:
The computer is information processing machine, a tool for storing, manipulating, and correlating data. Data tables can easily be generated. The time and effort required to understand increases with the numerous data. CG directly solves this problem. It is a study of techniques to improve communication between human and machine. A graphical presentation of the data eases out the problem. This is a passive form of CG.
Communication can also be a two way process. A dialogue can be established through the graphics medium for interaction. This is termed interactive computer graphics.
Basic concepts of Computer Graphics: Now a day all of us are very fond of video games and you may be good at playing them. For example a game named ping-pong. It’s a game played by two people with a pair video game controller and a home television set. You can see that when a game is switched on, a small bright spot, representing a ball, is seen bouncing to and fro across the screen. Now each player uses his video game controller to position a paddle to bounce the ball back to his opponent. The player who hits the ball past his opponent wins a point and the one who gains 15 points wins the game. Now how did you invent this video game? This has been done with the aid of Computer Graphics. Video games represent a major use in the home of computer graphics. Computer graphics helps to create and manipulate pictures with the aid of computers.
Computer graphics is concerned with all aspects of producing images using a computer. It concerns with the pictorial synthesis of real or imaginary objects from their computer-based models.
Different types of Computer Graphics: Computer Graphics can be broadly divided into two
• Non Interactive Computer Graphics
• Interactive Computer Graphics
Non Interactive Computer Graphics: In non-interactive computer graphics otherwise known as passive computer graphics, the observer has no control over the image. Familiar examples of this type of computer graphics include the titles shown on TV and other forms of computer art. Interactive Computer Graphics: Interactive Computer Graphics involves a two way communication between computer and user. Here the observer is given some control over the image by providing him with an input device for example the video game controller of the ping pong game. This helps him to signal his request to the computer. The computer on receiving signals from the input device can modify the displayed picture appropriately. To the user it appears that the picture is changing instantaneously in response to his commands. He can give a series of commands, each one generating a graphical response from the computer. In this way he maintains a conversation, or dialogue, with the computer.
Interactive computer graphics affects our lives in a number of indirect ways. For example, it helps to train the pilots of our airplanes. We can create a flight simulator which may help the pilots to get trained not in a real aircraft but on the grounds at the control of the flight simulator. The flight simulator is a mockup of an aircraft flight deck, containing all the usual controls and surrounded by screens on which we have the projected computer generated views of the terrain visible on takeoff and landing. Flight simulators have many advantages over the real aircrafts for training purposes, including fuel savings, safety, and the ability to familiarize the trainee with a large number of the world’s airports.