Computer Graphics Lecture 1: A Survey of Computer Graphics

Flashcards containing key terms and definitions from the lecture notes about a survey of computer graphics.

Pixels

Images are made up of pixels.

RGB Color cube

A color model used in computer graphics, along with HSV, YUV, YCrCb, and YIQ.

The “goal” of computer graphics

Solve the function Red @ a pixel is f(i,j)=… Green @ a pixel is f(i,j)=… Blue @ a pixel is f(i,j)=…

Data Visualization & Computer Aided Design (CAD)

Charts and Graphs; Better conceptualization, interaction, transfer of ideas

Virtual Reality (VR)

User interacts and views with a 3D world using “more natural”

Data Visualization

Scientific, Engineering, Medical data; Visualizing millions to billions of data points; See trends; Different schemes

Education and Training & Computer Art

Models of physical, financial, social systems; Comprehension of complex systems; Fine and commercial art, Performance Art, Aesthetic Computing SIGGRAPH Games/Movies

Image Processing

Inverse of Graphics; Start with a picture; Process picture information

Theory

Analytical Geometry, Vectors and Matrices

Algorithms

Line drawing, Filling, Lighting, Shading effects etc.

Implementation

Programming (OpenGL)

Graphics Hardware

Processor, Input Devices, Output Devices

Main players

ATI (http://www.ati.com/), and 3D Labs (http://www.3dlabs.com/), Nvidia (http://www.nvidia.com)

Logical Input Devices

Categorized based on functional characteristics; Each device transmits a particular kind of data; The different types of data are called input primitives (basic geometric shapes such as line, point, shape, etc).

Locator Devices

Coordinate position (x,y); Examples: Mouse, Keyboard

Stroke Devices

A sequence of coordinate positions; Example: Mouse, Trackball

String Devices

A string of characters; Example: Keyboard

Valuator

Scalar values (typically between 0 and 1).; Examples: Control Dials, Sensing devices

Choice

A selection from a list of options.; Examples: Mouse, Keyboard (Function Keys), Touch Panel etc

Pick

Selection of a part of the screen.; Examples: Mouse, Joystick, Digitizer.

Type of video display devices

Refresh Cathode-Ray Tubes (CRT), Flat panels Displays, Stereoscopic and Virtual Reality (VR) Systems

Electron gun

Emits a beam of electrons (cathode rays) that passes through focusing and deflection systems.

Focusing and deflection systems

Directs the beam toward specified positions on the phosphor-coated screen.

Phosphor-coated screen

Phosphor glows briefly when electrons strike it hard enough.

Refresh rate

Frequency at which a picture is redrawn on the screen.

Raster-scan Displays

The electron beam is swept across the screen, one row at a time, from top to bottom.

Aspect ratio

Number of pixel columns / number of scan lines

Frame buffer

A region of memory where the picture definition for the entire screen is stored sufficiently large to hold all the pixel values of the display surface.

Bilevel system

Monochrome / black-and-white

Random-scan Displays

Electron beam is directed only to those part of the screen where a picture is displayed.

Emissive displays

convert electrical energy into light.

Non-emisive displays

use optical effect to convert light from some other source into a graphics pattern.

Stereoscopic viewing

A technique for 3-Dimensional viewing; Provides 3D effects by presenting a different view to each eye of an observer so that scenes appear to have depth.

Hard-copy Devices

Line Drawing Devices & Raster Devices

Line Drawing Devices

Create pictures by drawing lines.

Raster Devices

Create pictures by displaying dots