What is Computer Graphics
Graphics : The Product of the graphic art.
Graphic art : The visual, descriptive & technical art involving drawing, printing, writing, design, etc.
Computer Graphics : The use of computers to generate and manipulate visual images. Or
The set of technologies used to create Art / Picture with computers
Definition
CG is the field of Visual Computing , where one utilizes computers both to generate visual images & to integrate or alter visual & spatial information sampled from the real world
Categories
Interactive CG :
- Users interact with the System.
- Two way of Communication.
- Both Graphical I/P and graphical O/P.
- e.g. Games.
Passive CG :
- No option for users to interact.
- e.g. Movies
Graphics Standard
- CORE SYSTEM
- GKS (Graphical Kernel System)
- PHIGS (Programmer’s Hierarchical Interactive Graphics standard.)
- CGI
- CGM (Computer Graphics Metafile)
Core System
- First Graphical standard ever developed.
- Provide a standardized set of commands to control the construction & display of graphics images.
- It contained mechanism for describing & displaying both 2d & 3D structures.
- But it lacked primitives for describing areas & could only create line drawing.
GKS
- Adopted as the first graphics software standard by ISO & by various national standard organization including ANSI.
- Contain Primitives for imaging areas & colors.
- Initially it did not contain the constructs for 3d objects.
- Later a 3D GKS extension was subsequently developed.
PHIGS
- An extension of GKS.
- Programmer’s toolbox intended for programming graphics application.
- Increased capabilities for object modeling, color specification, surface rendering & Picture manipulations are Provided.
- To Provide 3D surface-shading capabilities an extension of PHIGS (PHIGS+) was developed.
PHIGS
Does not Provide
- standard methodology for graphics interface to O/P devices.
- Methods for storing & transmitting Pictures.
